How to sharpen a drill at 90 degrees

How to sharpen a drill yourself

Almost every owner has a drill or hammer drill in his arsenal. Consequently, drills for household work are often used. However, everyone knows that any drill requires sharpening over time. However, not everyone knows how to sharpen a drill at home. To understand the principle of this procedure, read our article.

Typically, twist drills are used for work around the house. They can drill into both metal and wood. To understand how a drill works, you need to know its design.

During the drilling process, the cutting edges of the drill form a conical surface, so the bottom of the hole takes on a conical shape. The efficiency of drilling metal can be determined by the condition of the rear corner of the drill.

The fact is that each type of cutting tool and depending on the material being processed has an individual cutting angle.

How to sharpen

As a rule, drill sharpening is done using an electric sharpener. Sharpening begins with the need to form cutting edges. In this case, you should focus on the grooves of the drill, located in a spiral, along which the material chips are removed. During sharpening, the edge must be positioned parallel to the axis of the sharpener. The metal layer is removed from the drill gradually.

The procedure stops only when the reflected light of the edge is no longer visible. In this case, the drill must be held in a position parallel to the axis of the circle. The second edge is sharpened in the same way.

Sharpening angle

There may be different angles between the edges of the drill. This depends on the material for which the drill is used. Eg:

• for drilling steel you need a sharpening angle of 140 degrees;
• for wood or plastic, a sharpening angle of 90 degrees is suitable;
• For other materials, a drill with a sharpening angle of 120 degrees is used.

This drill is considered universal.

To sharpen the blade at the correct angle, it is best to use a template made of thick paper or cardboard.

Edge length and shape

When sharpening the drill, you need to maintain the same length of edges. As for the top of the drill, it should be located exactly in the center of its axis. Remember that metal is capable of reflecting light, so visually it may appear that the edges are not the same. To make sure the sharpening is done correctly, shade the drill on three sides and carefully inspect its outline.

Back edge surface

After you have sharpened the edges of the drill, you can begin processing their back surface. Their shape should be conical. To check the parameters of the rear surface, you can use a washer whose hole diameter is 2/3 smaller than the drill diameter. The surface of the edge is applied to the edge of the washer hole and it is determined how much metal needs to be removed to achieve the desired result.

When the edges have a conical shape as a result of sharpening, you need to form the back corners. In this case, the metal is removed in such a way that in the arc of the drill, for every millimeter, the gap between the washer and the drill itself increases by approximately 0.15 mm.

Make sure that the cutting edge is not damaged during operation. To prevent this from happening, a strip 0.2 mm wide is left on the last passes, which is not processed.

The edge on the other side of the drill will not be damaged if you use the near end of the sharpening wheel when sharpening.

Jumper

When a drill is sharpened, a bridge appears on the two rear surfaces, which prevents drilling, so it is necessary to make it small. However, it cannot be removed completely, since then the drill may break off in the center. If the drill is thin, for example, with a diameter of 6 mm, then the optimal length of the jumper is 0.7 mm. For a thick drill, a jumper of 1.5 mm is sufficient.

In production conditions, after sharpening, finishing is usually carried out, with the help of which the surface is smoothed and small nicks disappear. Moreover, this drill lasts longer than others. Therefore, if possible, it is best to fine-tune the drill after sharpening. For this purpose, use round grinding stones made of green silicon carbide on a bakelite bond.

Source: http://sdelais.ru/kak-zatochit-sverlo-samomu.html

How to sharpen a metal drill yourself

Sharpening a drill for metal can be done without contacting a specialist. It is well known that drilling tools become dull during use. The more it is used, the sooner it deforms.

How to determine if a tool is dull

Many people do not pay attention to the signs indicating the need to sharpen their drills themselves. They use the tool until it breaks completely, after which they buy another one. This is most often due to a lack of understanding of how to properly sharpen a drill for metal. It must be remembered that sharpening can be done with your own hands, at home. You will need special tools.

It is possible to make a hole in steel if the tool is well sharpened. If, when drilling, the area where the drilling fixture touches the part squeaks, it means the tool has become dull. It will begin to scroll and rub against the steel. In addition, heat dissipation will increase significantly.

Specialists usually use small instruments with a radius of less than eight millimeters. To sharpen blunt drills at home, you can use:

• sharpening device with an abrasive wheel;
• grinding device;
• electric drill with appropriate attachment.

You can use any other device on which you can place a special stone and ensure its torsion. The rotation speed must exceed eight hundred revolutions per minute.

Preparation

Before you start sharpening, put on glasses, gloves, and prepare a container with liquid. The smallest particles and sparks will fly from the sharpening device in different directions. If you do not cover your hands and head, they can injure the skin. The organs of vision will be particularly affected. At best, you will get away with minor problems with your eyes, at worst, you will go blind.

The container with water is intended for cooling the instrument. When sharpening, it will begin to heat up from friction against the rotating surface of the abrasive. If the tool is not cooled, it will overheat and break.

Sharpening procedure

How to sharpen a drill for metal? It's not too difficult. It is required to strictly follow the algorithm by which the procedure is performed. First of all, decide what type of drill sharpening to choose. The choice depends on the shape that the cutting parts of the tool should have.

To make sure that the device is sharpened correctly, look at it. If you did everything correctly, then:

• the cutting parts are of identical length relative to the axis of the drill;
• The sharpening angles of the elements do not differ from each other.

Drill sharpening should begin from the base of the tool, located at the back. It is necessary not to deviate from the angle set at the beginning. If you haven't done anything like this before, you may need to repeat the sharpening a couple of times. After each sharpening, carefully inspect the tool. The procedure must be repeated until the back becomes cone-shaped (when viewed from the left/right).

Next you need to sharpen the cutting part. There are various methods by which drill bits can be sharpened. Try to keep all parts the same shape.

If you sharpen in one plane, then the rear base is processed at an angle of twenty-eight to thirty degrees. This is a simple method that is used for instruments of small thickness (radius no more than one and a half millimeters).

The device must be applied at a certain sharpening angle to the abrasive element. Do not allow the tool to turn over or move. This will cause the cutting parts to scatter, especially when the metal is of low quality.

The cutting elements of tools with a large radius must be sharpened conically. This method is more difficult than the previous one. If you're not sure you can do the procedure correctly, practice on a part you don't need before sharpening.

How to sharpen a drill bit conically? With your left hand, grab the main one, and with your right hand, the tail section. The base should be near the fence cone. Otherwise, sharpening will not proceed correctly. Use your right hand to rock the instrument. A cone-shaped base will form at the back. A similar procedure must be carried out for the other part of the instrument. Make sure that the pen does not move away from the abrasive element even for a second.

Peculiarities

How to sharpen a metal drill correctly? Ensure that the rear of the drilling jig retains its original shape. This technique will allow you to accurately maintain the set sharpening angles of the drill. You will be able to sharpen tools with a radius of up to five millimeters with your own hands. How to sharpen larger drills? Sharpen the main parts of each nib separately.

When sharpening, the front and rear angles of the tool decrease, and the angle of the cutting edge increases. This ensures an extension of the operational period and a reduction in the width of the transverse edge.

When using the conical sharpening method, the nib becomes stronger. In production conditions, finishing is often carried out, which provides the opportunity to eliminate the smallest irregularities that remain after sharpening a metal drill with your own hands.

Using a template to set the angle

How to sharpen a drill yourself? This was written above. To eliminate errors, you need to check the correctness of sharpening with a special device - a template.

The template can be made from a sheet of metal (copper, aluminum, steel) having a thickness of approximately one millimeter. It is advisable to use steel sheets because they last longer than others. Using the template, calculate the sharpening angle of the wood/metal drill at the tip, the size of the cutting parts, the angle between the bridge and the edge. Instead of the back angle, which is quite difficult to calculate, it is necessary to measure the point angle.

If the lengths of the cutting parts and their angle of inclination to the tool axis are uneven, the load will be distributed incorrectly. As a result, the operating period will be shortened due to wear of the cutting parts, which are constantly in a state of overload.

Differences in the load on parts of the tool provoke its runout when processing the part. Because of this, the radius of the hole is larger than necessary. The easiest way to determine whether sharpening is correct is to try to make a hole using a drilling device. If the chips fly out unevenly, it means that the wood/metal drill was sharpened incorrectly.

Sharpening device

It is possible to make a sharpening unit yourself. It contains a large base and a small part with holes for drilling devices of different sizes. The device cannot be intended for sharpening any one tool. It must provide the ability to process tools of different diameters and lengths.

The base of the device, through which twist drills are sharpened, can be made of planed slats 3-4 centimeters thick. A wooden plank with a side bevel at an angle of 27 degrees must be attached to them at an angle of 32 degrees. This bar is intended for the correct orientation of the holder with the drill relative to the grinding element. The holder can be made from a block with a bevel at an angle of 62 degrees.

You already know how to sharpen a drill bit for wood/metal. It's not too difficult. You will need to be focused, patient and persistent, and careful. Only in this case will you be able to maintain the required sharpening angle of the metal drill. If you doubt your abilities, contact a qualified specialist.

However, remember one of the main advantages of sharpening yourself is saving money. The master will not sharpen your tool for free. The exception is when the specialist is your friend. You can also watch a video of sharpening a metal drill.

Nowadays, on the Internet you can easily find and download similar videos that clearly explain the process of sharpening a drilling device.

Source: https://oxmetall.ru/sverlenie/zatocka-sverla

How to sharpen drills for metal

Metal cutting implies the availability of only high-quality and well-fitted tools. With tools for wood, not everything is simple either, but for wood there are a lot of other tools and drills with their own characteristics - Forstner drills, feather drills, serrated bits. They are either rarely sharpened or not sharpened at all. You have to tinker with metal drills quite often, and today we will look at some points regarding sharpening.

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Which drills to sharpen and with what tool

A true owner will never throw away even inexpensive drills and will try to sharpen even a broken drill, since after refilling it can still serve for quite a long time. But for this it is necessary to restore its geometry in accordance with factory parameters. This partly applies to a feather drill for wood. Let’s figure out how to sharpen drills for metal correctly and how to sharpen them right now.

Since metal is harder than wood, you don’t have to think about sharpening wood drills for many months, or even years. Any metal, even the softest, cannot be processed with a dull and worn-out tool.

In addition to the fact that you can forget about the quality of the hole when using dull drills, the drilling process itself is accompanied by overheating of the tool, and this wears out the tool steel even more.

In production conditions, there are special devices for sharpening drills, there are also household sharpening machines for twist drills, but craftsmen, as a rule, use a universal sharpening machine; in extreme cases, if you have experience, you can fill the drill with an angle grinder.

Twist drill sharpening parameters

You can sharpen a drill using several methods, and the hardness of the metal being processed depends on this, and the diameter of the drill also plays an important role. However, in any case, it is worth paying attention to some points:

• when we sharpen a drill, its edge must be strictly parallel to the axis of the sharpening machine, ideally to the working surface of the grinding wheel;
• during the sharpening process, you should not rush and put excessive pressure on the edge;
• each cutting edge on each drill should be the same length as the opposite one;
• For each metal, it is necessary to at least approximately maintain its own sharpening angle.

Angle of sharpening, dependence on materials

It is based on the last point that you need to know the main angles that form the cutting edges:

• wood, aluminum and brittle materials require sharpening at an angle of 140 degrees;
• silumin alloys, magnesium, as well as plastics are excellent for drilling when sharpening the drill at an angle of 90 degrees;
• for drilling copper, a sharpening angle of 125 degrees is used;
• 120-130 degrees is the optimal angle for drilling soft bronze and brass;
• For drilling steel, cast iron and hard bronze, an angle of 116-119 degrees is used.

But how can such accuracy be maintained, since it is quite difficult to distinguish 120 from 118 degrees by eye? Of course it's difficult. For this, there are special templates against which the sharpening angles of the edges are checked. Knowing the angle, such a template can easily be made with your own hands, and over time the angle will be obtained automatically.

Methods for sharpening edges depending on drill diameter

Depending on the diameter of the drill, several edge dressing techniques can be used. For example, for a drill with a diameter of no more than 3 mm, single-plane sharpening is used.

This means that the working edge is sharpened only in a plane parallel to the working surface of the sharpening machine or its axis. There are some nuances, since with this straightening method the working edge of the drill can become chipped if you overdo it with the pressing force.

Therefore, this method must be sharpened carefully, especially since the drills are of small diameter.

For drills with a diameter of more than 3 mm, a more complex sharpening method is used - conical. To do this, the drill is held by the shank, the edge is gently pressed against the working surface of the grinding wheel. During the sharpening process, the drill body sways slightly, thereby giving the edge a conical shape.

Sharpening a Pobedite drill

A Pobedit drill for drilling holes in concrete is sharpened even easier - for this it is necessary to maintain the angle between the axis of the drill and the axis of the sharpening machine strictly 60 degrees, and the angle of rotation of the cutting edge must be within 170 degrees.

There is no hurry here, since there is a risk of grinding off most of the soldering, after which the drill will be unusable, but with certain skills, you can grind off the metal part of the drill, freeing a few millimeters of the pobedit soldering, if possible.

The most common mistake when sharpening a twist drill of any diameter is a negative angle between the cutting edge and the nozzle. To avoid this, you just need to make sure that the edge is in any case higher than the back of the head. Refuel the tool correctly and good luck to everyone!

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Source: https://nashprorab.com/kak-zatochit-sverla-po-metallu/

Wheel for sharpening drills for metal

When working with hard workpieces, the working surface of the drill wears out quickly. A dull drill becomes very hot and loses strength. This occurs due to the “releasing” of the metal. The tool must be sharpened periodically. However, this applies not only to drills.

Drills are inexpensive devices. In any case, those models that are used in the household. However, it is wasteful to buy a new tip every time it becomes dull.

There are factory-made sharpening devices, but this violates the concept of economical use of home tools.

Wood drills practically do not become dull, except that the tool can be “driven” at high speeds into a resinous workpiece. Pobedit tips for concrete and stone cannot be sharpened. All that remains is to sharpen the drill for metal. Many experienced locksmiths carry out this procedure with their own hands, without any equipment.

However, the accuracy of the work leaves much to be desired, and not every home craftsman has such a professionally developed eye. In any case, minimal mechanization is necessary.

How to make a homemade device for sharpening drills?

First of all, you need to acquire a means of control. No matter how you sharpen the drill, you need a template to check the accuracy of the work.

Conventional drills for working with ferrous metals have an edge angle of 115-120 degrees. If you have to work with different materials, check out the table of angles:

Processed material	sharpening angle
Steel, cast iron, carbide bronze	115-120
Brass alloys, soft bronze	125-135
Red copper	125
Aluminum and soft alloys based on it	135
Ceramics, granite	135
Wood of any species	135
Magnesium and alloys based on it	85
Silumin	90-100
Plastic, textolite	90-100

Knowing these values, you can prepare several templates and, in accordance with them, sharpen yourself. In this case, you can use the same drill for different workpieces, you just need to change the angle of the top of the working area.

The simplest, but very effective sharpening device is bushings of different diameters, mounted on some kind of base.
Schematic drawing of the device in the illustration:

It is best to make a whole clip of copper or aluminum tubes, to fit standard drill sizes. Or drill a sufficient number of holes in a block of soft material. The main thing is to install a comfortable tool rest on your sharpener, which will allow you to move the sharpening device at the right angle and serve as a reliable support.

Our grandfathers used this method. Only an oak block was used as a material for the manufacture of a sharpening machine - an angle.

In principle, it was enough to place a table or workbench opposite the side surface of the emery - and the sharpening machine was ready. At the same time, the quality and accuracy of processing was at a high level.

There are different drawings of sharpening devices.

You can use a ready-made one, or develop it yourself. The main thing is to understand the principle of working with a drill.

If the tool turns even a millimeter, it will be damaged and you will have to grind off some distance for reprocessing.

After finishing sharpening, let the drill cool and take measurements using a template. Both edges must be symmetrical to within tenths of a millimeter. This is especially important for small diameter drills.

The diagram shows typical mistakes in self-sharpening:

1. The angles are chosen correctly and symmetrically - and the lengths of the cutting edges are not the same. The drilling center is offset relative to the drill axis. When working with such a tool, beats will occur; when you start drilling, it will be impossible to accurately hit the markings. The drill is highly likely to break;
2. Centering is accurate, cutting edge angles are asymmetrical. When creating a hole, only one cutting working part will work. Drilling will be slower and the tip will quickly overheat. It is possible for the hardened metal to “release” from heating. In addition, the hole will be broken, and its diameter will be larger than the diameter of the drill.

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The design of a sharpening machine for twist drills for metal, made from scrap materials

The basis is a household sharpening machine with a proud inscription “made in Germany”, which has all the signs of a product from the Middle Kingdom. However, it works properly, there is no axle runout, and it maintains speed under load.

The technical specifications are as follows:

• the tool rest must be strictly on the same horizontal line (or above it) with the axis of rotation of the emery;
• the design is durable and reliable, ensuring work safety;
• It should be possible to sharpen both manually and semi-automatically - using a device;
• The shape of the tool rest allows you to freely lower the drill shank to the required angle.

No scarce parts are required to manufacture the device. All the materials were actually lying underfoot in the barn. The processing of the workpieces was carried out with a grinder, the same modernized sharpener, and welding.

Since the emphasis was supposed to be made swinging (for semi-automatic mode), a loop connection was made. The holes of the tube, bracket and bolt are precisely selected to ensure there are no backlashes. The resulting device has two degrees of freedom.

The platform can be rotated along the vertical axis - changing the sharpening angle of the drill. This axis is fixed. The tool rest can also swing based on a horizontal axis, ensuring proper articulation during sharpening. This degree of freedom is not fixed.

For the base plate, metal with a thickness of 4 mm was chosen, the remaining structural elements were 3 mm thick. The strength is more than sufficient. The tool rest is rigidly connected to the emery body. Of course, attaching it to the protective casing is unacceptable, so we screw the bracket using an additional metal “cheek”.

The actual guide plate for drills is screwed to the tool rest (more precisely, to the support plate). The plate is 5 mm thick and has a triangular groove cut into it for fixing the drill during processing.

The rotation angle of the structure is 90 degrees. This will ensure sharpening in any way, from the Leontiev method - to pressing at one angle with the development of an acute angle of the edge due to the curvature of the sandpaper.

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The drill bit being processed is not only firmly held in the groove - it can be freely fed to the abrasive along the groove, without the slightest deviation of the sharpening angle.

Due to the slight excess of the plane of the base plate above the axis of rotation of the disk, the optimal shape of sharpening the back of the working edge is achieved.

The accuracy of the work is the highest; a template is actually not required. It takes some time to install the device and adjust the angle, but you can quickly sharpen a couple of dozen drills without spending any effort.

If you need to sharpen a drill with a carbide attachment, the swinging plate can be fixed at a fixed angle. To do this, you just need to place a couple of washers under the axle nut.

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A few words about the emery wheel

Typically, for universal tasks, a white corundum wheel is used in a home sharpener. It sharpens knives, axes and shovels very well. It can be used to quickly process metal workpieces.

When sharpening carbide drills (and high-speed metal also requires a harder disc), a green abrasive wheel made of silicon carbide is used.
Such circles are marked 64C. The grit size for household work is usually 25H.

When sharpening drills, a finer fraction is required; it is better to work in the range 8H - 16H. It must be remembered that silicon carbide sandpapers become very hot during operation. Therefore, you cannot keep the drill in contact with the abrasive for a long time. After 2-3 approaches, let the metal cool. It is best to cool it with water and soda.

The peripheral surface of the emery, as the main processing surface, must be perfectly flat. You can straighten it with a CBN nozzle. For discs of small diameter, it is quite possible to get by with pliers that hold the CBN cutter.

Source: https://respect-kovka.com/krug-dlya-zatochki-sverla-po-metallu/

Drill sharpening angles for different materials

High-quality processing of materials such as metal and stone is impossible without the use of drills made of good materials, the geometry of the cutting part of which matches the required values. During operation, any, even the most durable drill, sooner or later wears out, losing the sharpness of the working surface. In such a situation, you need to decide whether to purchase new material, or look for information on how to sharpen a drill for metal.

Drill wear

Improper storage of the tool leads to the blades hitting each other, the adhesion of particles of the surfaces being processed and general contamination of the spiral. This factor negatively affects the service life of drilling tools, so it is recommended to store them in special cases and stands.

In addition to storage conditions, wear life depends on the purpose of the tool and the surface it processes. For example, drills designed for working with wood retain their working surface for several years due to the fact that wood is a relatively soft material.

Due to the fact that metal is a harder and more durable material, drills for working with it wear out much faster. Working with a blunt tool is unacceptable, since the holes will take longer, be more difficult to make, and will not turn out smooth.

The drill itself will become very hot, causing further wear to occur even faster and will certainly lead to the tool breaking. In addition, a breakage is often accompanied by the scattering of small fragments at high speed, which can lead to various injuries.

Signs that a drilling tool has become dull include:

1. Creaks and other non-standard sounds made during operation;
2. Strong heating of the tool;
3. Low quality of created holes.

Working with a dull drill is difficult, often impossible. In addition to the fact that it does not drill the workpiece, the use of a worn drilling tool threatens to break it, which often leads to damage to the workpiece and to difficulties in removing the broken part of the tool stuck inside the surface.

In order to extend the life of the drilling tool and return the correct geometric surface, a procedure such as sharpening is performed. Any craftsman who often works with a drill should know how to properly sharpen drill bits for metal.

Safety precautions

The work described below is hazardous, so a certain set of rules must be followed:

1. The machine must have a protective casing and screen that protect the worker from flying sparks and dust.
2. Before turning on the machine, you need to make sure that the sanding wheel is securely fixed.
3. Sharpening cannot be done by weight; you need to rest the tool on a tool rest.
4. If the drill is broken, it can shatter into small fragments; in addition, during the work a lot of abrasive dust is produced and sheaves of sparks are cut out.

   Taking this into account, all work should be carried out wearing protective glasses and a mask.

Sharpening process

It is advisable to properly sharpen a drill for metal using special devices and machines.

Unfortunately, in a home workshop, such equipment is not always available, and usually sharpening metal drills with your own hands is done on an electric sharpening machine with abrasive materials, for example, on stone wheels.

Sharpening is carried out along the rear edges, and all teeth should be sharpened absolutely identically. At the same time, it is difficult to manually maintain a given angle and the desired shape, and the easiest way to sharpen at home is only spiral and crown tools.

Work surface angles

In order to know how to sharpen a drill for metal on a sharpener, you should remember a number of important parameters applied to the cutting part, the implementation of which guarantees a high-quality result:

• The angle of the rear part of the tool relative to the drilling plane = 10°,
• Front sharpening angle = 20°
• Cutting tool tip angle = 118°

In this case, the angle at the apex may vary , depending on the material to be worked with:

• For stainless steel, cast iron and hard bronze - 115−118°;
• For aluminum - 130−140°;
• For copper - 125°;
• For soft bronze - 130°.

As you can see, the softer the material in which you want to drill a hole, the tighter the angle should be. So, for stainless steel, 118° is enough, and for softer metals the angle reaches 140°.

There are several types of sharpening used for different purposes. the most common are:

1. Single-plane. With this type of processing, the back surface of the feather is made in the form of a single plane. The rear angle lies in the range of 28−30°. The drill is placed with the cutting part parallel to the grinding wheel and its position is not changed. It is considered the simplest type of sharpening of drills with a diameter of up to 3 mm, but the disadvantage is that the cutting edges may crumble during the drilling process.
2. Conical sharpening.

   Typically used for relatively large diameter drills. It is difficult to carry out without special equipment and without the appropriate skills. The drill should be taken with your left hand by the working part closer to the cone, and with your right hand hold the tail. The tool is then pressed against the end of the whetstone with the back surface and the cutting edge.

   During the sharpening process, the drill is slightly rocked by the tail with the right hand, this allows you to create a cone-shaped surface on the feather edge.

During the sharpening process, you should try to maintain the original factory surface of the rear part so that it retains the angles given to it. After sharpening, it is advisable to carry out fine-tuning, which will smooth the surface and remove small nicks.

Finishing the material after sharpening

Finishing is carried out on special finishing wheels. They differ from conventional grinding wheels in that they combine aggressive processing of the material to produce a good surface finish.

Due to the softness of the material and high-quality abrasive, such wheels are ideal for removing scratches and other surface defects; their removal is carried out without changing the geometry of the working part of the material. As a rule, such circles are installed on a grinder or drill , which makes it possible to more conveniently and accurately process a drill clamped, for example, in a vice.

Source: https://MyTooling.ru/instrumenty/ugly-zatochki-sverl-dlja-raznyh-materialov