How to sharpen a small drill

How to properly sharpen a drill bit for concrete at home - basic methods

To make holes during construction work, it is recommended to use a drill and pobedit drills. They are characterized by precision in operation and long service life. When the drill wears out, you can sharpen it yourself

Basic rules for sharpening

Before sharpening a concrete drill at home, you need to familiarize yourself with the basic rules for this procedure:

• Sharpening a drill for concrete should be carried out in compliance with the optimal body temperature. It is strictly forbidden to overheat it, as this will lead to damage to the product. This rule must be followed if the drill is made from a titanium-based hard alloy.
• If the drill accidentally overheats, it is strictly forbidden to lower it into water. It should cool down naturally.
• The work needs to be done gradually. Initially, a small part of the drill is sharpened. After the sharpened section has cooled, we proceed to the next one.
• During the work process, it is recommended to focus on equality of angles.
• The cutting edges of the drill must be of the same length, since under high loads the tool will be pushed to the side, which causes breakage.

Sharpening of drills used in a drill or hammer drill must be carried out in strict accordance with the rules, which will ensure their excellent performance.

Methods

When drilling into hard materials, only the edges should come into contact with them. That is why the back surface is sharpened at a certain angle. As a result of this operation, a gap appears between the edge and the bottom of the hole.

Using a conical sharpener

The drill is inserted into a special prism of the sharpening machine, which moves around its axis. The prism is positioned at a certain angle in relation to the grinding wheel. The back of the drill is shaped like a cone. It is located in the place where the working surface of the grinding wheel intersects with the swing axis.

In order to properly sharpen the drill, you need to first configure the parameters. The axis of the sharpening cone should be located at an angle of 45 degrees relative to the axis of the drill itself. Cone sharpening can be performed using two methods:

1. The top of the cone that will be sharpened should be located below the top of the sharpening cone. It is first recommended to carry out the adjustment in accordance with the specified parameters: a - 45 degrees, b - from 13 to 15 degrees, n - 1.9d. the drill axis and the cone must intersect at an angle that is less than the angle of the grinding wheel and drill. If we sharpen using this method, we need to make sure that the tip of the drill is located above the top of the sharpening cone. The tip and the drill should be 1.06 in apart. The axis of the drill and the axis of the cone should intersect at an angle of 90 degrees.
2. In order to ensure the rear angle for the peripheral point, it is necessary to provide indicators - a-5-7 degrees, angle 2f - from 116 to 118 degrees. the cutting transverse edge should be at an angle of 55 degrees.

Using screw sharpening

If there is a need to automate the process of sharpening drills, then the use of the screw method is recommended. It lies in the fact that translational movements are coordinated with the rotations of the grinding wheel. With its help, you can simultaneously sharpen the front and rear corners.

When screw sharpening, the rear angles of the working part increase as they approach the center. When using this method, there is a decrease in the strength of the transverse edge of the drills, which leads to their breakage when drilling excessively hard materials.

Two-plane sharpening

Using this method, it is recommended to sharpen drills that are intended for drilling non-hard materials. If the diameter of the drill is less than 3 mm, then the use of this sharpening method is recommended. Using this method, drills are sharpened at an angle of 60 degrees. Thanks to this method, products are improved rather than errors are corrected.

Features of pobedit drills

To produce products, high-strength metals are used - tungsten, cobalt, which are mixed with carbon. With the help of such tools, drilling is carried out in brick, stone and other materials of a high level of hardness. The Pobedit plate is fastened to the steel tail using copper soldering. The diameter of the drill is measured in cylindrical sections.

The drill has a conical surface and is characterized by abrasion resistance. The product is resistant to high temperatures. But, it is characterized by fragility, so sharpening work must be done carefully. In pobedit drills, only the trailing edge is most often sharpened.

How to sharpen a pobedite drill bit?

When sharpening, you need to pay attention to symmetry, since in its absence the tool will wear out. Pobedite drills require sharpening only the back edge at an angle of 60 degrees. During work, you need to ensure the uniformity of the plane. It can be identified by its reflection. Several reflections indicate that the drill is sharpened in several planes. In this case, repeated sharpening is carried out until one plane comes out.

If the leading edge of the Pobedit drill is covered with solder, then you need to sharpen it too. The work consists of removing excess metal along the axis of the tool and opening the vibrator. It is not recommended to overdo it in this case, as this can lead to loosening of the fastening of the plate to the steel axle. When sharpening, you need to ensure that there is a bridge between the front and rear edges.

Sharpening at home

When sharpening drills with your own hands, the user is advised to adhere to safety rules. When working on sanding wheels, safety glasses must be worn. This will protect your eyes from abrasives and pieces of scale. Glasses must be used even if there is a protective screen on the sandpaper.

It is strictly forbidden to carry out work wearing gloves. The drill may get caught in the thread, causing hand injury. It is recommended to carry out work in tight-fitting clothing, the buttons of which are pre-fastened. It is recommended to adjust the support so that the gap between it and the stone is small.

Sharpening drills can be carried out in various ways, which allows a person to choose the most suitable option for himself. To avoid injury, you must adhere to safety precautions during work.

Source: https://1beton.info/maloetazhnoe/instrument/kak-zatochit-sverlo-po-betonu-v-domashnih-usloviyah

Sharpening drills for metal: how to properly sharpen a drill with your own hands, video tips - SibNovStroy

Twist drills are used to create holes in metals. No matter how durable the tip material is, sooner or later the tool will lose the sharpness of the cutting edge.

Signs of dullness:

• when rubbing against a workpiece, a sharp creak is heard;
• the chips come out in small crumbs, not in a spiral;
• During drilling, intense heat occurs.

If any of these signs are present, you will need to sharpen your drill bit. Moreover, there is no need to wait for the sharp edges to be completely ground down. When working with a blunt tip, it becomes so hot that the hardened metal “relaxes” and rapidly degrades.

It would be better for you to reduce the length of the tool by 0.5-1 mm with each sharpening, but the device will always be sharp and will last longer.

The next extreme is to throw away the blunt instrument and buy a new one. You don't throw away dull knives or an ax, do you? So the drills need to be sharpened.

Unlike cutting tools, this process is regulated by certain standards.

How to sharpen a drill correctly, and what should be the angles of the working edge

The main angle at the tip, which determines the ability to process different metals, is the development of the tip edges.

Its value varies for different materials.

• Hard steel – 140°;
• Stainless steel – 135°-140°;
• Deep drilling – 130°;
• Cast iron - double angle. Main – 118°, auxiliary – 90°;
• Aluminium, brass, bronze – 118°;
• Copper and alloys based on it – 100°.

To understand how to properly sharpen different angles, you need to understand how many of them the drill has and where they are located. For example, consider the components of the working part and the tip angles for processing stainless steel:

As you can see, the tool consists of a large number of components, each of which does its own job. However, not all edges will have to be sharpened by hand. Yes, and you can control the process using a universal template.

Metal drills look the same, with the exception of special models that are not used in everyday life.

The shank and neck require no maintenance. Of the working part, only the cutting part is sharpened. The ribbon, intended for the formation and removal of chips, is manufactured at the factory. It is almost impossible to process it at home or even in an industrial environment.

The cutting edge consists of a back and front surface that meet at an acute angle. It is this edge that scrapes chips from the workpiece, going deeper into the surface and forming a hole.

If the edge is not sharp, has dents and irregularities, drilling becomes very difficult, and banal idle friction of metal on metal occurs.

How to sharpen a drill for metal

Unlike a knife or an axe, a simple whetstone is not enough. For sharpening, you will need an abrasive wheel rotating at speeds of up to 1500 rpm. The most convenient device is a sharpening machine.

The disc must be fine-grained. The size of the fraction according to the standard marking is 8H-16H. The material of the emery wheel is silicon carbide. Such abrasives have a characteristic greenish tint. Material marking – 64C.

Experienced craftsmen sharpen by hand, using only a tool. The correctness of the angles is checked with a template. However, there are a number of devices to facilitate work and increase processing accuracy.

The choice is quite wide, you can choose a machine to suit every taste and budget. Many “Kulibins” make their own devices.

You just need to set the required angle according to the table, secure the drill in the rack - and control the heating.

IMPORTANT! When sharpening, the working edge heats up so much that the hardened metal can “release.” The tip will lose hardness and wear will occur faster.

Therefore, you need to feed the tool with short movements, 2-3 seconds each. If necessary, after each approach the tip can be cooled with water and dissolved soda.

If you work with drills on an industrial scale, it makes sense to buy a semi-automatic sharpening machine. This can be either a separate specialized machine or an attachment to a power tool.

In both cases, your participation in the work is minimal. The quality of processing in such devices is ideal, but the cost is quite high.

Don't despair, the wise Chinese have figured out how to sharpen drills inexpensively and efficiently. The attachment on a regular screwdriver does the job slowly, but efficiently. And the price tag is more than humane.

And yet let's return to the traditional manual method.

This is exactly how almost all home mechanics sharpen metal drills.

Before starting work, you need to decide what type of sharpening you need to process the working part of the drill. Cutting edges are sharpened in the following ways:

1. single-plane;
2. two-plane;
3. conical;
4. cylindrical;
5. screw.

First, the back surface of the edge is sharpened. The thickness of the removed material should be such that not a single defect remains on the edge. If there are dents of 1-2 mm on the drill, you will have to shorten the nozzle to this length.

During the process, we periodically inspect the working edge. The edges must be symmetrical, the jumper must be smooth, and be located exactly in the middle between the working edges.

Drills with a diameter of up to 3 mm are sharpened using a single-plane method. After giving the correct shape to the back surface, the drill using a tool rest or other device is pressed against the sandpaper at an angle of 25°-30°.

IMPORTANT! The working surface of the abrasive wheel should “run” onto the sharpening surface. Otherwise the edge will be uneven.

During the sharpening process, the drill should not be rotated or changed angle. This is necessary to give the edge a perfectly flat shape. In addition, when turning, part of the metal of the working edge may crumble.

A tool of such a small diameter can be sharpened in one go, so there is no need to worry about overheating.
You can cool the drill in a soda solution when changing the sharpening plane. We inspect the working tip - the edges should be identical and have an equal angle of inclination.

We check the correct angle using the template. If it doesn’t work out the first time, you can’t rework the edge. It needs to be sharpened again.

Tools with a diameter of more than 4 mm are sharpened using a conical method. The technique requires certain skills, so before processing valuable drills you should practice on those that you don’t mind ruining.

ADVICE! Try not to throw away broken drill bits. Firstly, you can practice sharpening skills on them, and secondly, the shank of a broken tool can be used as a drift or cotter pin.

The conical method is fundamentally different from the single-plane method. The drill is held with two hands (the size of large specimens allows this).

After the cutting edge touches the abrasive, the drill is rotated along the back side to give it a conical shape.

IMPORTANT! During the process, do not tear the drill off the sandpaper. Each approach starts from the working edge and ends with a full turn to the end of the back surface.

After each approach, the working part is checked against the templates in all three corners.

You can sharpen large drills using a planar method. However, with this method, the drill will have difficulty removing chips from the hole and will overheat greatly.

How to store new and sharpened drill bits

When storing and carrying, drills should not rub against each other. When you take the tool out of the common box, the sharp working edges become dull against their neighbors. The best option is individual holes or sleeves for vertical storage. And if you sign the dimensions, searching for a drill of the required diameter will not take much time.

Of course, indoor humidity should not lead to corrosion. For a detailed description of how to properly sharpen a drill, watch this video.

Source: https://sibnovostroy.ru/stanki/zatachivaem-svyorla-po-metallu-kak-pravilno-zatochit-sverlo-svoimi-rukami-video-sovety.html

How to sharpen a drill correctly: features of drill sharpening

Very often in everyday life we ​​use a tool such as a drill. Everyone knows that this thing is irreplaceable and should always be at hand. You can quickly make a hole in the right place using a drill, for example, to hang a mirror.

The tool always comes with a set of drills of different diameters, thanks to which you can easily drill a hole in the wall.

During operation, parts become dull and need to be sharpened. Most owners solve this problem simply - purchase new ones. And some take matters into their own hands and sharpen the details to a shine.

Here we will describe in detail how you can sharpen metal drills efficiently and quickly.

You will need:

• a small machine or grinding wheel;
• drills that need to be sharpened;
• bowl of water;
• glasses that can protect you from dust.

The main thing is to understand the principle of the whole process.

Spiral sharpening

Most often, metal drills need sharpening. These elements must always be sharpened, otherwise the work will stall. A bad drill will heat up the drill, causing it to wear out even more. If you hear squeaking and humming, it's time to sharpen the part.

While at home, it is better to use a sharpening machine with a small stone. As for sharpening methods, this will directly depend on the desired shape of the back of the part.

The forms can be different, namely:

1. Screw.
2. Single-plane.
3. Two-plane.
4. Cylindrical.
5. Conical.

Sharpening of the product should be done exclusively along the back edge. The 2 teeth should be sharpened equally.

Important! Doing this process yourself will be inconvenient. Also, in addition to the inconvenience, it is very difficult to maintain the required angle and maintain shape.

Planar option

Single-plane sharpening is characterized by a clearance angle that averages 30°. During operation, the part must be turned towards the grinding wheel so that its cutting part runs parallel to the circle. In this case, the product cannot be twisted; it must be in one position.

Conical version

If you want to sharpen the drill more than 3 mm, then you should choose the conical method. This is a very complex, labor-intensive process that takes a lot of time. You need to grab the part by the tail with your right hand, and with your left hand grab the work area closer to the intake cone.

For grinding, the product should be pressed firmly against the end of the stone with its back surface and cutting edge. Next, you need to slightly rock the part with your right hand, thus forming a conical surface on the edges. The main thing is to sharpen the product carefully and smoothly, without removing your hand from the sharpening tool.

Important! When sharpening the part, you should try to preserve the factory shape of the drill at the back of it.

In the process of working with wood, the products practically do not become dull, they can be used for a long time, they completely retain their original characteristics, which cannot be said about drills for metal and concrete. By periodically sharpening parts, drills will make holes faster and better, and their service life will increase.

Source: http://amstafkomanda.ru/remont/kak-pravilno-zatochit-sverlo-osobennosti-zatochki-sverla.html

How to sharpen a drill for metal? Sharpening device. Drill sharpening angle - expert advice:

The technological process of mechanical processing of materials includes many different operations, which require high-quality and sharp tools. Thus, in a machine shop at any machine-building enterprise, a set of turning, milling, drilling and more complex machines can be used. They use their own type of tool, each of which has a specific sharpening method.

Features of drills

Mechanical processing of metal involves enormous loads on the tool. In general, it consists of three main parts: connecting, body and cutting. So the cutting part is a small wedge-shaped element designed to penetrate the metal and remove part of it from the workpiece.

If, for example, in a turning tool or a disk cutter everything is clear with the shape and design of the cutting part, then when processing holes on a drilling machine everything is much more interesting and complicated, so you need to know how to sharpen the drill correctly. This is a tool designed for axial metal processing. That is, the feed movement is directed strictly along the axis. This should be taken into account before sharpening a drill for metal, because an incorrect cutting angle will lead to vibration and breakage.

Main elements of the cutting part of the drill

Before sharpening a drill for metal, you should familiarize yourself with the design of its cutting part, which includes the following elements:

1. Main cutting edge.

2. Auxiliary helical cutting edge (ribbon).

3. Jumper.

4. Front surface.

5. Back surface.

What will you need for sharpening?

At the enterprise, everything necessary for instrument restoration is always at hand. But the home craftsman has to look for an alternative to high-quality factory devices in simpler solutions that can be used in a regular garage. And yet, before sharpening a drill for metal, stock up on the minimum set:

1. Grinding wheel. It must be installed on a rotating shaft. The device is popularly known as “emery”. It is very common in the garage.

2. Coolant container.

3. Coolant (water or engine oil).

In order to maintain the sharpening angle of the drill, such a set may not be enough. After all, you will have to control the process “by eye,” which is unlikely to happen without some experience. In this case, the basic kit must also include a device for sharpening the drill, which you can buy or make yourself.

Controlled parameters

When everything is ready, you need to familiarize yourself with some theory in order to have an idea of ​​​​the basic parameters of an axial cutting tool. Before you sharpen a drill correctly, you need to know its angles:

1. Front. Defined in the main cutting plane (runs perpendicular to the main cutting edge) as the angle between the rake surface and the main plane (perpendicular to the cutting speed vector). It is directed tangentially to the drill circumference.

2. Rear. Also defined in the main cutting plane as the angle between the flank surface and the cutting plane (passes through the velocity vector and the cutting edge).

3. The point angle is between the two main cutting edges when looking at the drill from the side.

The optimal value of the front angle is 18-20 degrees, the rear angle is 10-12. The tip angle in metal drills has a standard value of 118 degrees.

Sharpening process

Now let's talk about how to sharpen a metal drill using regular sandpaper. The main sharpening of this axial tool is carried out along the rear surface. To do this, turn on the emery, firmly grasp the drill in your hand so that the main cutting edge is directed towards the rotation of the sharpener.

Now we bring the edge to the sharpener, after which we turn the drill by the shank so that the cutting edge is parallel to the surface of the circle. We perform the same operation with the second cutting edge.

The result is the so-called simple sharpening of the drill, which is optimal for most metal processing modes.

Simple sharpening is used for drills with a diameter of up to 10 mm. By increasing this parameter, you can additionally sharpen the front surface. As a result, the rake angle decreases, which means the thickness of the blade (the so-called cutting edge angle) increases and, accordingly, the service life of the drill.

Sharpening using a jig or machine

The method described above can be called artisanal, since precise control of the drill parameters directly during sharpening is simply impossible to achieve. In the best case, you will check the angles after finishing sharpening, and in the worst case, you will simply check how much better the drill has become. How to sharpen a drill correctly?

Of course, for this it is better to use more advanced options that will allow you to adjust to certain angles in advance. In this case, you will need a device or machine for sharpening drills.

https://www.youtube.com/watch?v=wY2X2IkNmf8

If the scale of work in your workshop is large enough and tool sharpening is required constantly, then purchasing a machine would be optimal. It will significantly simplify the process, especially if you need to resharpen carbide drills for metal.

The main advantage of its use is the exact adherence to predetermined parameters. When there is a large volume of work, it is unacceptable to use an incorrectly sharpened tool, as this will lead to a decrease in productivity.

Modern sharpening machines allow you to obtain different types of drill sharpening:

1. X-type. Mainly used for drilling blind holes. Designed to reduce axial cutting force.

2. XR type. Used for universal drills. The penetration into the material is somewhat worse than in the first type, however, such drills have increased strength and durability.

3. S-type. The point described above is used here, which also allows you to increase the service life of the drill when processing various materials (from cast iron to stainless steel).

4. N-type. A point is also used, but of a smaller size. Drills with this sharpening are used for deep drilling.

Device design

As has already become clear, manual sharpening of a drill is the work of a professional who not only knows the correct angles, but also feels the cutting process. Unfortunately, such an instinct comes only after many years of practice working with a drill press or drill. There is no need to experiment, as you can make it yourself or purchase a sharpening device. In both cases, it will include the same structural elements and work according to the same principle.

So, the main task of the device is the correct orientation of the drill relative to the plane of the grinding wheel. To do this, its design includes a base plate, on which it is desirable to place both the device itself and the electric motor on the shaft of which the sharpener is located. The plate also contains a rotating column on which the drill is fixed. It must be able to not only rotate, but also move towards the grinding wheel.

As a column, you can use any bearing assembly with a shaft, for example from an old drill. A drill bed is fitted onto the shaft rings (you can use an adapter sleeve), to which it is pressed with screws.

After fixing the drill, the sharpener drive is turned on, the column is brought to the grinding surface and rotated to give the back surface of the drill the correct shape.

It is important that when initially setting up the device, the drill tip angle is maintained at 118 degrees.

Sharpening with attachments

Another simple and convenient method involves using a device such as a drill sharpening attachment. Its main advantage is its versatility and ease of use. The device has a cylindrical shape.

On one side there is a connecting unit, through which the attachment is installed on the drill spindle. On the other side there are holes for installing drills of a certain diameter.

To sharpen, the drill is inserted into the hole, after which the sharpening mechanism is driven by the drill motor.

Security measures

Drill sharpening is associated with the formation of small particles that come off the sharpener during wear. They heat up and fly in different directions in the form of fiery sparks, so for safety you should use safety glasses and gloves.

When sharpening a drill without a jig, make sure to securely fix its position. Otherwise, upon contact with the sharpener, it may simply be torn out of your hands.

Source: https://www.syl.ru/article/156979/new_kak-zatochit-sverlo-po-metallu-prisposoblenie-dlya-zatochki-ugol-zatochki-sverla---sovetyi-spetsialistov

How to sharpen a drill correctly

Often, household appliances such as a drill are used. Every owner knows what a reliable assistant this power tool is. It easily drills holes of different diameters in the required places. This is only possible thanks to drills.

Drills may need sharpening during operation. Some decide to simply replace them by buying new ones. But in most cases, old drills can be brought back to life. In this article we will tell you how to sharpen a drill correctly.

Let's look at the differences in sharpening drills for wood, metal and concrete.

What you need to sharpen a drill at home

No matter what materials the drill is used for, you must prepare the following tool and material in advance:

• Protective glasses.
• Water container.
• Drill.
• Grinding wheel or sharpening machine.

Sharpening machine

In most cases, drills up to Ø16 mm are used at home. Therefore, you should not have any particular difficulties when sharpening such drills. The most important thing is to understand the principle of this process.

Sharpening a twist drill

As for wood drills, they need to be sharpened extremely rarely. The same cannot be said about metal drills. Such a drill should always be sharp. How do you know if a drill needs sharpening? When drilling begins, it makes a characteristic creaking sound.

A worn drill quickly heats up the product and, accordingly, wears it out even more. As a rule, drills are sharpened on special machines; at home, you can use a small sharpening machine with a stone.

So, how to properly sharpen a drill for metal? The method and type of sharpening will directly depend on the required shape of the back surface of the drill. For example, it could be:

• Single-plane.
• Two-plane.
• Conical.
• Cylindrical.
• Screw.

Twist drill

In any case, the drill is sharpened along the back edge. Two teeth are sharpened equally. If you decide to do this manually, it will be quite inconvenient. Moreover, it will be extremely difficult to maintain the required shape of the back edge and angle manually.

Flat drill sharpening

Single-plane sharpening is characterized as such because the back of the nib has one plane. The rear angle averages 28–30°. When sharpening, the drill must be placed against the circle so that its cutting part runs parallel to the circle. In this case, the drill cannot be rotated or moved. This manual sharpening method has one drawback: the cutting edge of the drill is chipped. But at the same time, for a Ø3 mm drill, this is the easiest method of manual sharpening.

Conical method

If you want to sharpen a drill larger than Ø3 mm, then the conical method is chosen. Although it is difficult to sharpen using this method, it is possible. With your right hand you should take the drill by the tail, and with your left hand by the working part closer to the intake cone.

The drill is pressed against the end of the grinding stone by the cutting edge and the surface of the rear part. With your right hand you need to shake it slightly, thereby forming a conical surface on the edges. Hand movements should be smooth and slow; hands should not be lifted from the stone.

To sharpen the second feather, the procedure is repeated.

Drill sharpening angle diagram

During the sharpening process, it is advisable to maintain the factory shape of the rear part of the drill, this will allow you to maintain the desired clearance angle.

What is the purpose of such a point? The drill resource increases by reducing the rake angle, and the angle of the cutting edge increases, respectively, all this increases the resistance of the drill to chipping. The width of the cross edge will automatically become smaller. This edge does not drill into the metal, but only scrapes it in the central part. If possible, you can fine-tune the drill.

This process refers to the removal of burrs after sharpening. So, the drills will last much longer. For this process, you can use grinding stones made of green silicon carbide on a bakelite bond, hardness M3-SM1, grain size 5–6, stone grade 63C. In addition, you can take a grinding wheel made of CBN LO on a bakelite bond with a grain size of 6–8.

How to sharpen a pobedite drill bit

Sharp pobedit drill

As a rule, a Pobedite drill bit is used for concrete. It may also need sharpening. During the drilling process, a dull drill bit will become very hot and, accordingly, may make a characteristic squealing sound. If you want to save money on buying a new one, then you can try sharpening the drill yourself. To do this, it is enough to prepare:

• Sharpening machine with diamond wheel.
• Coolant.

If the soldering on the cutting part of the drill is 10 mm high, then you can sharpen the Pobedit drill.

Scheme for sharpening a Pobedit drill

It is important to take into account one well-known fact: the harder the material, the lower the sharpening speed should be. On a Pobedit drill, you only need to correct the slick edges, so sharpening it will be quick. It is important not to rush the process, otherwise there is a risk of licking off the excess surface of the drill. It is necessary to sharpen the front surface of the drill.

In the case when the soldering has already been ground down to the base of the drill, sharpening will be required. In order for the thickness of the soldering center to be smaller, it is necessary to sharpen the front surface at the same time. After sharpening, both cutting sides must be the same size, otherwise the holes will be uneven and enlarged.

When sharpening a Pobedit drill, it is important to maintain an angle of 170°; this is especially necessary if the material is quite hard.

Pobedite drill

It is not allowed to overheat the drill during sharpening. The carbide plates may peel off and the surface may crack. Therefore, during the process, you should cool the drill in water or oil from time to time.

So, we have looked at the basic principles of sharpening drills for wood, concrete and metal. You can share your comments!

After watching the following videos, you will learn how to sharpen twist drills. This video tutorial covers sharpening technology in detail in four parts.

Processing the back surface of the drill:

Grinding the drill jumper:

Technology for sharpening small-diameter drills, carbide drills and others:

Source: https://kakpravilnosdelat.ru/kak-pravilno-zatochit-sverlo/

How to properly sharpen a drill for metal: methods and videos

Tools become unusable over time: they become dull, break and crack. Not all consequences of use can be eliminated, which is why you have to purchase new devices, but some can still be restored and given a second life. This is especially true for drills, which during use can not only break, but also become dull.

• Types of drills for metal
• How to sharpen a product at home
• Methods for sharpening drills for metal
• Finishing after sharpening the drill
• Recommendations for sharpening metal drills

Types of drills for metal

Today it is possible to make a hole in non-ferrous metals, steel, cast iron without the use of special equipment. For such purposes, you only need a high-quality drill and good drill bits.

This type of product comes in different shapes. For example, a cutting tool in the form of a spiral , which is formed by several longitudinal grooves that remove chips. Such a device is usually called a spiral device.

A metal drill can also be of this type:

The latter type has a conical shape . Using this product, holes of various diameters are drilled depending on the final and initial circumference of the cone. It is easier to work with the former, because each step in them means a certain diameter, and when using the latter, you will have to constantly monitor the process.

Core drills are best used for drilling large diameter holes. They are also effective for multi-layer drilling of several sheets of metal at once. Due to the design of these products, there is no need to use more powerful tools, since the cutting forces are kept low.

In order for the core drill to last as long as possible, it is necessary to ensure that there is no vibration and the metal is cooled. When purchasing them, you need to pay attention to tools with reinforced shanks that do not slip in the chuck.

Shanks are mainly produced in conical and cylindrical shapes. Hexagons are very rare. Tools with a cylindrical shank are fixed in a three-jaw chuck, so their diameter does not exceed 12 mm.

Of course, industrial products with a tapered shank are designed for drilling machines. Their maximum size can reach 60 mm. If the cone of the tool and the spindle do not match, then use an adapter sleeve .

Drill markings

Drills are marked with special symbols. They most often indicate the steel grade and diameter. True, on too small instruments up to 2 mm nothing is noted. Products with a thickness of more than 3 mm also carry information about the manufacturer and accuracy class .

When the drill is made of high-speed steel, it is marked in the form of the letter P. The remaining numbers with letters indicate how much and what component is in the alloy.

Suppose if the device says K6, that means six parts cobalt . When choosing long metal products, you should pay attention to the presence of such a component, because it improves the heat resistance of the product.

Signs of a dull metal drill

Most people continue to do necessary work with a dull tool until it breaks. As a result, they have to throw it away and buy a new one.

This happens because inexperienced craftsmen simply do not know how to sharpen drills. You can even restore a dull tool yourself, using tools available in any workshop.

Drilling should only be done with a sharpened product. If, when creating a hole, you hear a creaking sound in the place where the drill comes into contact with the metal, it means that it has become dull.

In this case, the tool will rub strongly against the steel, rotate and generate heat during operation. It’s better not to wait for the device to break, but to move on to sharpening a metal drill with your own hands.

How to sharpen a product at home

Home craftsmen usually do not use large metal drills at home; the most popular sizes are 0.5-18 mm. Of course, it is best to do the work of sharpening such tools on a machine. If you don’t have such equipment, then a small sandpaper that everyone has in their garage will do.

In addition, to sharpen a drill for metal, you can use an attachment on an electric drill or grinder . But before work, it is necessary to firmly fix the power tool on a flat surface. With their help you can make a rotating sandstone or sharpening disc.

You can make a device for sharpening drills with your own hands. When processing them, do not forget about safety precautions. It is imperative to carry out work wearing safety glasses to avoid injury.

Moreover, it is important to cool the product , otherwise the steel will lose strength, so you need to periodically lower the tool into a container with cold liquid. The water should be placed near a fixed power tool or sharpening machine.

Methods for sharpening drills for metal

Single-plane processing at home. This option is used when it is necessary to sharpen products no more than 3 mm.

The disadvantage of this sharpening is that the edge may chip during operation. This technique requires special care. Its essence is that the drill is applied to the circle and moves parallel to the working surface .

Sleeve or two-plane sharpening

This option is widely used by craftsmen to sharpen products. In this case, special bushings are used. First of all, you need to take the drill in your left hand by the working surface, then you should bring it to the fence cone, holding the device by the tail with your right hand.

The cutting edge of the product will be pressed against the end of the grinding wheel and, as a result, the drill will rotate around its own axis with the help of your right hand. In this way the back surface of the tool will be sharpened.

the correct angle when rotating the tool , formed between the end of the grinding stone and its inclination. It is for this purpose that special bushings are used to maintain the sharpening angle of the metal drill.

Conical sharpening

When you start sharpening twist drills with your own hands, first they process the back part, and then the cutting part. The work is carried out as follows:

• First of all, the surface of the device must be pressed against the grinding wheel or stone so that there are no gaps left.
• When sharpening, the angle must be kept the same at all times.
• It is necessary to pay attention to the tip of the product from the side: if the back surface is processed correctly, an even cone will be visible.
• Then you can proceed to sharpening the cutting edge with your own hands, while strictly observing the angle.

Using attachments for sharpening metal drills

This convenient method involves the use of special devices for sharpening products. The advantages of this method include ease of use and versatility . This device has a cylindrical shape.

It contains, on the one hand, a connecting unit, with the help of which the attachment is put on the drill spindle, and on the other, there are recesses for installing drills of a certain width. To process it, you need to insert the product into the hole, after which all that remains is to set the device in motion with the drill motor and maintain the sharpening angle.

Finishing after sharpening the drill

Without finishing the product, it will not be possible to eliminate roughness and achieve a smooth surface. In addition, drills that are subjected to finishing acquire wear resistance .

It is advisable to perform it with grinding wheels made of green silicon carbide . When making adjustments, it is important to maintain the symmetry of the axes. To avoid mistakes, it is better to check the correct sharpening of the drill angle with a template , which you can make yourself from the following materials:

Sheets of them should have a thickness of approximately 1 mm. Steel products are the most durable. Using the template, you can find out the length of the edges for cutting, as well as the angle between the jumper and the cutting part. It should be done before starting to use a new tool in order to transfer the required angles from the last one.

The easiest way to determine the correctness of the point is to carry out test drilling . When the cutting feathers are sharpened unevenly, in the less loaded part, chips will come out of the hole in small quantities. Sometimes it flies out through only one recess. Moreover, the diameter of the excavation made may exceed the thickness of the drill.

After sharpening a drill for metal, you need to pay attention to its symmetry. To make sure that the work was done correctly, you will need a regular drill . Using this tool, they drill into plastic and then check which side will produce more chips. It is this edge that will need to be refined.

Rules for storing new and sharpened products

When carrying and storing metal drills, you must ensure that they do not rub against each other. Remember that when removing the device from the general box, the cutting working edges will become dull on adjacent products.

Therefore, it is better to make individual sleeves or holes to store them in a vertical position. On top of that, it is recommended to sign the dimensions so that searching for a drill of the required size does not take much time. Of course, it is necessary to control the humidity in the room to avoid corrosion of products.

Recommendations for sharpening metal drills

Spiral products should be processed along the trailing edges. They should turn out exactly the same after work.

Moreover, this is not so easy to do, especially in manual mode, since it is necessary to maintain a certain shape and angle of the tool during sharpening.

Before you start sharpening a cutting tool, it is advisable to practice first on non-working products. It is also worth considering the fact that the drilling is performed by the side edges of the device.

Sharpening is carried out to return the cutting part of the product to its factory shape. When working, you should adhere to the basic rule for sharpening tools with tips made of various alloys: the harder the material of the drill being processed, the lower the sharpening speed.

Source: https://instrument.guru/osnastka/kak-pravilno-zatochit-sverlo-po-metallu-sposoby-i-video.html

How to sharpen a metal drill with your own hands +

about sharpening a twist drill

Twist drills must be sharpened along the back edges. It is worth noting that both cutting teeth should be treated in the same way. Don't forget that you need to sharpen the tool's feathers the same way, and creating the desired configuration of the back edge by hand is quite difficult.

It is customary to use special machines for sharpening. However, at home you can use a regular sharpener as a sharpening tool.

Depending on the shape of the back surface, there can be several types of sharpening:

1. Single-plane.
2. Two-plane.
3. Conical.
4. Cylindrical.
5. Screw.

In the first case, sharpening of the rear surface of the cutting blade is performed in the form of a continuous plane. Typically, the clearance angle should vary between 27-31 degrees. With single-plane sharpening, there is a high probability of chipping the cutting edge. This method must be done manually using a gimlet with a diameter of 2-3 mm.

Universal drills with a diameter of more than 3 mm are usually subjected to conical sharpening.

In order to more clearly demonstrate the features of such sharpening, let's look at the diagram.

The illustration shows the grinding wheel, the back surface of the gimlet and the cutting edge.

Imagine a cone whose generatrix is ​​directed along the cutting edge of the drill and the end of the grinding wheel. The angle at the top of the figure is 26 degrees. The axis of the cutting tool intersects with the axis of the geometric figure and forms an angle of 45 degrees.

It can be seen from the figure that if you begin to rotate the gimlet around the axis of the cone, a conical surface is formed on the rear face. If the axis of the cutting tool and the imaginary cone are in the same plane, the clearance angle of the drill will be zero.

In order to form the correct back angle, it is necessary to slightly shift the axis of the gimlet in relation to the cone. The larger the offset, the larger the clearance angle will be.

It is no secret that it is practically impossible to comply with all these conditions when sharpening by hand. But if you still decide to sharpen the drill yourself, proceed as follows:

Method 1.

1. Take the drill that will be sharpened by the working part with your left hand. With your right hand, grab the ponytail.
2. Then press the cutting edge and back surface of the gimlet against the end of the grinding wheel.
3. After this, with smooth movements of your right hand, without lifting the drill from the sharpening stone, rock it. This will create a conical surface at the rear end.
4. Repeat this operation for the second pen.

Method 2.

The next sharpening method will be a little easier.

1. As in the previous method, take the working part of the gimlet with your left hand and the tail with your right hand.
2. Press the cutting edge of the tool against the grinding wheel and rotate the drill around its axis. It is very important not to tear the gimlet away from the sharpening machine and maintain the desired angle of inclination to the end of the grinding wheel.

As a result of sharpening, conical surfaces should form on the back surface of the cutting feathers. It is no secret that due to friction with the grinding wheel, the tool overheats. This leads to the tempering of the hardened part of the drill. As a result, the metal begins to gradually lose the necessary hardness. Therefore, it is better to sharpen with repeated cooling of the gimlet.

As a coolant for ordinary drills (for example, for wood), you can use simple distilled water or a water-soda solution.

However, you should not use it if your tool is made of carbide materials (for example, concrete drills). Also, under no circumstances should you use oil to cool the drill.

If you sharpen a tool dry without cooling, you need to remember a few rules:

1. Do not remove too much metal in one pass.
2. The rotation speed of the grinding wheel should be moderate.
3. Do not overheat the gimlet.
4. Sharpen the tool against the movement of the grinding wheel. This is necessary so that the cutting edge of the drill does not break off or become wrinkled during operation.

Is finishing required after sharpening the drill?

As practice shows, without finishing it is impossible to achieve a smooth surface of the cutting tool and remove small roughnesses. In addition, drills that are fine-tuned become wear-resistant.

For finishing, it is best to use grinding wheels made of green silicon carbide. During the finishing process, it is very important to ensure that the axes are symmetrical. The cutting feathers must be the same length and have the same apex angles.

It is worth noting that the correct sharpening of the gimlet must be checked using special templates. They are made from sheets of the following metals:

Using a template, you can check the point angles and the length of the cutting feathers. The clearance angle is almost impossible to measure, so your best bet is to observe the angle of the point.

If the cutting edges have uneven length and slope, loads of different magnitudes appear over the entire surface of the tool. Because of this, the drill will wear out faster. Therefore, immediately after sharpening, perform a test drilling. It will help you determine the uniformity of the cutting edge feathers.

How to sharpen a wood drill correctly

Wood drill bits are less susceptible to wear than metal cutting tools. To sharpen a drill for wood, you need to get a sharpening machine. Don't forget to stock up on water. It will be needed as a cooler.

If you don’t have a machine, wood drills can be sharpened even with a file, but this process will be long and painstaking.

You can also adapt for this a homemade machine from a drill, into the chuck of which a circle with fine sandpaper is clamped.

How to sharpen a small drill

It does not require special proof that the drill during operation loses the sharpness of the cutting part, that is, simply put, it becomes dull. A dull drill isn't a problem until it's needed.

Then it suddenly turns out that it is impossible to work with a worn or dull drill. We can only regret that the geometry and size of the drill were not restored in time.

This article will tell you how to sharpen a twist drill and a hard-tipped drill bit for drilling concrete.

How to sharpen a twist drill correctly

You don’t have to worry about sharpening a wood drill; you can work with such a drill for many months and even years without any sharpening. Unfortunately, the same cannot be said about a metal drill, which must be sharp. That is, you can drill metal only with a sharp, well-sharpened drill.

Loss of drill sharpness is characterized by a sharp creak at the beginning of drilling. A drill that is not sharpened in time generates more heat and thus wears out even faster than a sharp one.

You can sharpen a drill on special machines or using devices. Naturally, if possible, it is preferable to do this on special equipment. But in a home workshop, as a rule, there are no such machines, so you have to use a regular electric sharpening machine with a stone.

Main components of a twist drill.

So, let's look at how to sharpen a drill for metal? The type of sharpening depends on the shape that should be given to the back surface of the drill and can be single-plane, two-plane, conical, cylindrical and helical.

The drill is sharpened along the back edges. Both teeth (feathers) of the drill should be sharpened exactly the same. It's not easy to do this manually. It is also not easy to manually maintain the desired shape of the back edge and the desired back angle.

1. Single-plane drill sharpening is characterized by the fact that the back surface of the pen is made in the form of a single plane. The rear angle ranges from 28-30°.

The drill is simply attached to the circle, so that the cutting part runs parallel to the circle and sharpening is carried out without rotating or moving the drill.

With such sharpening, the cutting edges of the drill may become chipped during drilling, which is a disadvantage of this sharpening method. This is the easiest method of manual sharpening, which can be used for a thin drill with a diameter of up to 3 mm.

2. Drills with a diameter of more than 3 mm are preferably sharpened conically. It is difficult to perform such sharpening manually without skills, but it is possible. The drill is taken with the left hand by the working part as close as possible to the fence cone, and with the right hand by the tail.

The drill is pressed against the end of the grinding stone by the cutting edge and the back surface, and is slightly rocked with the right hand, creating a conical surface on the back feather edge. During sharpening, the drill does not come off the stone, hand movements are slow and smooth.

For the second pen everything is repeated in the same way.

Move the drill with its cutting edge to the grinding wheel.

We swing the drill down and then up again.

When sharpening, you should try to maintain the original shape of the factory surface of the rear part as much as possible in order to maintain the desired rear angles. If sharpening is done correctly, then it is quite sufficient for drills with a diameter of up to 10 mm. For diameters above 10 mm, this sharpening can be improved by sharpening the front surface, as shown in the photo:

Front surface point.

What is the point of a point? By reducing the rake angle and increasing the cutting edge angle, chipping resistance increases, which increases drill life. In addition, the width of the transverse edge becomes smaller. The transverse edge does not drill, but scrapes the metal in the central part of the hole. The second picture clearly shows that here it is shortened, which makes drilling easier.

For drills with a selected small clearance angle, you can further sharpen the flank. In this case, the drill rubs less in the drill hole with its back surface. See photo:

Rear surface undercut.

In production conditions, after sharpening, as a rule, finishing is done, which smoothes the surface, removing small nicks. A drill that has been fine-tuned wears out less than a simply sharpened drill. If possible, fine-tuning should be done.

For finishing, you need to use grinding round stones made of green silicon carbide (grade 63C, grit 5-6, hardness M3-SM1) on a bakelite bond, as well as wheels made of CBN LO (grit 6-8) on a bakelite bond.

Below we present to your attention an excellent selection of training videos by watching which you will definitely be able to sharpen your drills.

Manual sharpening of twist drills. Part 1

Even the strongest drill becomes dull over time. It is irrational to throw away and buy a new one, because when grinding off a knife or an ax, they do not get rid of it, but sharpen it and continue to use it. The same should be done with drills. Of course, their processing is much more complicated, so you need to carefully understand how to sharpen a drill for metal.

When to sharpen a drill

A sharp creaking sound during operation is a sign of grinding, since this sound occurs when the drill rubs strongly against the workpiece. It’s also time to sharpen the tool if, when drilling, the chips look like crumbs rather than spiral strips. After use, you need to touch the drill; if it is too hot, the cutting edges are dull and excessive friction occurs.

If any sign is detected, you should immediately stop working and sharpen the drill. After all, during friction, the metal heats up greatly. At the same time, it changes its physical and mechanical properties and becomes soft. Moreover, even after cooling it will not return its qualities, since the hardening is “released” with such heating.

As a result, the tool becomes unusable. Therefore, it is better to sharpen drills too often than too rarely. There is no need to be afraid that a lot of metal is removed from them. Reducing the length of the tool when sharpening will not harm its operation, but heating during friction will damage it very quickly.

Drill geometry and parts

Before figuring out how to sharpen a drill for metal, you need to understand the structure and geometry of this tool. The components of the structure are shown in the figure below.

In the picture you need to find the following parts that will be useful later:

• Cutting edges are the ones that remove chips from the metal during operation.

• Posterior surfaces (back of the head).

• Flutes for chip evacuation.

When sharpening, the back surfaces and the bridge are processed. The cutting edge is formed by the plane of the groove and the back. It is the back surface that is processed when the tool is sharpened. The shape of the back, in particular the lower position relative to the cutting edge, is necessary so that the edge is higher than the back surface when drilling. This is required to reduce friction during operation and transfer all the pressure to the cutting edge.

The curvature and inclination of the cutting edge must be determined with a special template, trying it on to the center of the drill. The main parameter of the tool is the apex angle, which is formed by the cutting edges. It is he who determines what metal can be drilled with a bur.

The degrees for drilled objects are as follows:

• for thick sheets – 130;

• for cast iron, 2 angles are made: main - 118, additional - 90;

• aluminum, bronze and other metals of medium hardness – 118;

• copper and other soft metals – 100.

Source: http://gidpotolok.ru/info/kak-zatochit-malenkoe-sverlo/

How to sharpen a small drill

Sharpening a drill at home is not difficult if you know how. The difficulty in this matter is maintaining the correct angles. After all, at home, as a rule, there are no special mandrels and conductors. There is only a sharpening machine. At least, we will proceed from such conditions.

Equipment requirements

The only equipment we have is an electric sharpening machine. But just because it exists does not mean that you can sharpen drills on it. It is necessary that the sharpening disk has the correct shape - that is, the shape of a cylinder with a smooth, not rounded edge. A convex edge with ground edges may result in incorrect sharpening.

If the disk is very worn out, it is better to replace it with a new one or correct it with a special CBN “pencil”, if you have one on the farm. It is very good if the disk is balanced and does not produce beats or vibrations (in fact, this is a mandatory norm). Only the peripheral surface of the disk is involved in the work, not its ends.

There is a temptation to use the flat side surface of the disk. But after several sharpenings it will lose its shape and fixing the stone after that will be much more difficult.

Sharpening auger for concrete

The hammer drill has a carbide plate as the cutting part, inserted into a slot at the working end and secured with solder. A normally sharpened drill has clear cutting edges with a sharpening angle of about 90 0 and an angle between the edges at the apex of 130–140 0.

With standard sharpening, the front edge of the cutting edge (directed in the direction of rotation) is inclined to the drill axis at an angle of 30 0, and the rear edge is inclined at an angle of 60 0. When manually sharpening, without special tools, you can focus on the entire, unworn part of the edges and reproduce their angles of inclination.

Sharpening process

We start sharpening from the front edges. We position the drill near the peripheral surface of the stone so that the cutting edge is parallel to the axis of the sharpener and directed upward, and the edge is parallel to the surface, and lightly press the drill against the sharpener for a short time.

A clearly visible mark remains on the metal, which shows whether its position was chosen correctly. The plane of the test section should coincide with the plane of the edge, and the spot of the section should be located in the center of its unworn part, without significant displacement.

Having found the correct position experimentally, remember it and begin sharpening.

Parallelism is not difficult to achieve if you bring the cutting edge to the surface of the stone and navigate along the gap left before contact.

You should not immediately achieve a sharp edge. Remember that you still have to grind down the back edge, and then the edge will “fall into place.”

First, the front edges are sharpened one after another. Then you need to check their symmetry. This is done visually, in the light, by placing the drill head near the edge of an object. The edge should be smooth or concave, but symmetrical. You can make a special template for testing. If there is asymmetry, a shorter edge is additionally ground down.

After this, the back edges of the edges are also ground down one by one, followed by checking for symmetry. The symmetry of the arrangement of the edges is also checked when viewed from the end, along the axis of the drill. When sharpened correctly, they are parallel, and between them there remains a bridge about 0.2–3 mm long, depending on the diameter.

If, as a result of processing, the cutting edges do not become sharp, there are visible roundings or cavities on them, the entire sharpening cycle must be repeated.

Add-ons

When sharpening, it is important not to overheat the tool. To cool, it is periodically dipped in water. A container of water should be kept near the machine. Do not press the drill against the sharpener for a long time. It is better to work with short touches, about 2–4 s, with breaks for the same amount of time. In this case, excess heat has time to be removed by the body of the drill and the risk of overheating the edge is reduced.

To work on soft materials without impact, for example on brick or tile, the cutting edges are brought “to zero”, without a jumper, and their sharpening angle is reduced to 30–35 0.

How to hold the drill while processing

Since, according to the conditions of the task, we do not have devices for precise positioning of drills, all hope is in our own hands. There are several simple techniques to achieve a “steady hand.”

It is best if, when sharpening a drill, you can rest it on a tool rest - a special “table” fixed in front of the sharpener. If you cannot achieve the desired position with direct support on the tool rest, you can hold the workpiece in your hands, but be sure to lean on it:

• fingers on the rest;
• with your wrist or hand on a workbench, on your knee, on any stable and conveniently located object;
• elbow or forearm on a workbench or knee.

As a last resort, you can simply press your elbows to your sides, forming a triangle with your arms and torso. But in any case, you need to find a way to hold the tool as tightly as possible with minimal effort.

When fixing the drill during operation, you should remember its position not only visually, but also by the sensations in your hands. Muscular, kinesthetic memory may be more accurate than visual control.

To maintain sharpening symmetry, it is useful to move to the second edge by turning the drill around the longitudinal axis, without changing the position of the hands and body. If you don't need a cooling break.

Sharpening a drill for metal

When sharpening drills for metal, only the back surfaces of the cutting edges are ground down. These surfaces have a rounded shape (with a drill diameter of less than 3 mm - flat) with a decrease relative to the edge of about 10 0. The cutting edges converge to the top of the drill at an angle of 116 - 120 0 (sharpening angle). For brass, copper, soft bronze, this angle is increased to 125–130 0, for aluminum - up to 140 0.

Sharpening

When sharpening, the drill is held with both hands. One near the sharpener, the other by the shank. The fingers of the hand closest to the sharpener (leading) rest on the rest. If it is not there, you need to find any support, as described above.

The drill is positioned at an angle to the working surface of the grindstone: 60 0 horizontally (half the angle at the apex) and about 10 0 vertically. The sharpened cutting edge is directed upward and located horizontally, parallel to the axis of the stone.

The position can be selected when the machine is turned off, according to the shape of the gaps between the edge and the sharpener when viewed from above, and between the sharpener and the back surface when viewed from the side.

To more accurately set the sharpening angle, you can draw a clearly visible line on the tool rest at the desired angle.

When sharpening, the drill is pressed against the sharpener by the cutting edge, and then, without changing the pressure and horizontal angle, it is tilted with the shank down until the back surface is completely processed. In this case, the position of the leading hand does not change. After 1–3 such passes, the drill is rotated around the longitudinal axis by 180 0, and the operation is repeated for the second edge. The tool is rotated only with your fingers, without changing the position of your hands.

After sharpening, you need to check the symmetry of the edges - the equality of their lengths and angles of inclination to the axis of the drill. If one of the edges is shorter, it needs to be sharpened again. The equality of the angles is checked visually - against the light or using a simple template; the length of the edges can be measured with a caliper.

Additional processing

When sharpened correctly, the cutting edges do not meet at the top; a short bridge remains between them. To reduce resistance to entry into the material, the bridge is ground off with the angle of a sharpening stone or a diamond file.

Grinding is carried out on both sides, symmetrically, at an acute angle to the axis of the drill, and the edge of the resulting groove is located at an angle of 30 0 to the cutting edge.

The purpose of this operation is to shorten the jumper, but not to grind it off completely! Without it, the drill will not be centered upon entry.

The lintel is stitched using drills with a diameter of more than 3 mm. But in practice, for simple work without high loads, the jumper, as a rule, is not ground down even with a diameter of 10 mm or more.

Checking the sharpness

After sharpening, you need to check the tool in operation and, if necessary, correct it. There are several signs that indicate sharpening errors.

• Poor alignment at the entrance; during operation, beating is noticeable - asymmetrical sharpening of edges or bridges.
• When working, you can hear the squealing of metal, the drill gets very hot, the chips look like small grains - a large angle of sharpening the edge, insufficient lowering of the back surface (blunt edges).
• Increased rotational force, chips quickly form on the cutting edges - the sharpening angle of the edges is too small (excessively sharp edges).

Source: https://master-kleit.ru/origami/kak-zatochit-melkoe-sverlo/

Sharpening drills for metal: how to properly sharpen a drill with your own hands, video tips

There is probably no need to prove that any tool, including metal drills, has one unpleasant property - becoming dull during operation. Moreover, the speed of this process directly depends on the frequency of use of the drill and the volume of work performed by it.

Very often a person does not pay attention to this until the drill completely becomes unusable, after which it is simply thrown away, which is extremely wasteful. And this happens for the simple reason that not many people know how to properly sharpen drills for metal, despite the fact that all the work can be done independently, with improvised tools that can always be found in the workshop of the real owner.

How can you tell if a drill bit has become dull?

very sharp tools can be used to process metal . If during the process of drilling a hole you hear a not very pleasant grinding sound in the place where the drill touches the metal, then this is the first sign that the tool requires sharpening. If such an unpleasant sound appears, it is advisable to stop all work.

If this is neglected, then during rotation the drill will begin to generate a lot of heat, which, together with friction, will lead to accelerated wear of the tool.

Typically, craftsmen use drills of small diameter up to 16 mm for household needs. Naturally, it is more convenient to sharpen them using special equipment, but the cost of such devices for everyday use is unreasonably high and therefore they are purchased extremely rarely. However, in the pantry or garage of a zealous owner there is always a device that can be used to sharpen a tool:

• a sharpening glass with a wheel made of abrasive material;
• Sander;
• electric drill with a special attachment.

Any other tool on which you can attach a sharpening stone and set it in rotation is also suitable for sharpening a drill for metal. However, it is necessary that such a device provides a rotation speed of at least 1500 rpm.

Preparatory stage before sharpening

Before you start sharpening a tool, you need to prepare eye protection glasses and gloves to avoid damaging your hands, as well as a jar of plain water. There is probably no point in explaining the importance of safety precautions, since human health comes first.

During operation, microscopic metal particles , sparks and grains of the abrasive wheel can fly away in a chaotic manner. If exposed areas of the body are not protected, metal shavings and dust can penetrate the skin. But unprotected eyes are especially dangerous if they get into them, as any foreign body can cause serious health problems.

In turn, a jar of water will be needed to cool the drill being sharpened, since during the friction of the surfaces of the sharpener and the tool, a large release of thermal energy occurs. If timely cooling of the drill is neglected, it will overheat and during its intended use it can quickly break or become dull again.

Technological sequence of sharpening

Naturally, simply preparing protective equipment and a sharpening machine is far from enough. You cannot start working without familiarizing yourself with the technology of sharpening drills, for which it is advisable to watch the video. Even though the procedure itself is not too complicated, however, it requires strict adherence to the sequence of work.

In addition, you need to know how to sharpen different drills. This can be determined by the shape given to the cutting edges of the device. Today, experts are considering single-plane, two-plane, conical, cylindrical and helical methods of tool sharpening.

To determine the quality of sharpening of the drill, it is necessary to carefully examine it after completion of the work. The main factors that indicate that the instrument has become sharp are the following:

• upon completion of sharpening, the cutting edge of the drill must remain symmetrical with respect to its axis;
• adjacent cutting edges must remain equal in length relative to the central axis;
• the parameters for inclination of the angle of the pointed edges should also remain the same.

Sharpening the drill should start from the back surface of the tool and continue in accordance with a certain sequence.

1. The rear edge of the cutting edge is pressed as tightly as possible against the sharpening surface. It is very important to maintain the initially set angle at all times.
2. Without any skills, the procedure may not work the first time. Therefore, you need to be prepared to make several attempts.
3. After each attempt, it is important to carefully examine the shape of the drill.
4. Work should continue until the back surface of the tool is given the correct conical shape.

Only after the required shape has been obtained can you proceed to sharpening the cutting surface. When carrying out work, it is necessary to ensure that the sharpening of each pen is the same. Maintaining the correct sharpening angle is of great importance.

In the case of the single-plane sharpening method, the back surface is processed in one plane while maintaining an exact angle within 28–30 degrees . This method is considered one of the simplest and is used for tools with a cross-section of less than 3 mm. However, to fully understand the process, it is advisable to watch a video on how to properly sharpen a drill.

When performing work using this method, the drill is pressed at a set angle to the surface of the grinding wheel. During the sharpening process, the tool is moved without turning it over. This can often cause the cutting edge to crumble, especially if low-quality metal was used to make the drill.

To sharpen the cutting edge of a tool with a large cross-section, use a conical sharpening. This option is more complicated than those discussed earlier and therefore you need to familiarize yourself with the video, and then adhere to certain stages of work .

1. The working part of the tool is taken in the left hand, and the tail end in the right hand. The working part must be kept as close as possible to the intake cone.
2. Without changing the position, the drill is pressed with the cutting part and the rear surface to the end part of the grinding wheel.
3. With the right hand, in which the tail edge of the instrument is held, rocking movements are performed so that a cone shape is formed on the side of the rear edge.
4. After one feather has been sharpened, they move on to the second, repeating the entire process exactly.
5. An important nuance of this procedure is that the drill cannot be torn off the surface of the grinding wheel.

There is another method of conical sharpening . To do this, the drill is also taken in the left hand from the side of the cutting edge, and in the right hand at the opposite end. But only the working part of the tool is pressed against the grinding wheel. With smooth movements, without leaving the sharpener, the drill is rotated around its axis, thereby uniformly sharpening the back surface of the tool.

Nuances of drill sharpening that you need to know

When carrying out work, it is important to try to maintain the shape of the tool that was given to it at the factory. Thanks to this, the correct angle is maintained. Conical sharpening is used mainly for drills with a cross-section of up to 10 mm. For larger tools, additional sharpening is required.

During the sharpening process, the size of the front and rear corners , and the angle of the working edge will increase. This increases the service life of the tool and reduces the width of the transverse edge, which does not take part in drilling.

In industrial conditions, after the tool is sharpened, finishing is performed. This event allows you to get rid of small nicks left after the main process. Thanks to this, the drill is less subject to wear. Therefore, if possible, it is better not to neglect finishing.

Figuring out how to properly sharpen metal drills is not that difficult, especially if you watch a video of the work being carried out. When doing all the work yourself, a person must be patient, since not everything always works out the first time. If you don’t have the patience and desire to sharpen the tool yourself, you can turn to specialists for help or simply purchase a new drill.

Source: https://stanok.guru/metalloobrabotka/sverlenie-otverstiy/kak-zatochit-sverlo-po-metallu-video-pravilnoy-zatochki.html