How to sharpen a knife with sandpaper
Recently, a large number of disputes and questions have arisen on such a topic as sharpening a knife with sandpaper. Connoisseurs of natural stones consider this some kind of perversion. But as soon as you start an argument with them, ask a few questions about physical processes head-on, in the end it turns out that there are no special differences. There are only solutions to one problem that are different in technology.
But let's look at this issue from the financial side, which is very important in modern realities.
High-quality natural stones have a more than decent price, and for good sharpening you will need a “good” set. Considering that the most modest and small set contains 5-6 stones, the total cost is about 8-10 thousand rubles. And if, by an absurd accident, it turns out to be gold, the pebble will fall and shatter into pieces, which does not happen so rarely. “Mere mortals” have the feeling that you have dropped an expensive porcelain vase that is 200 years old.
Another, not very pleasant, side of the coin is that no one can give you a guarantee that stones even from the same batch have the same characteristics; usually this value is highly averaged. This situation is due precisely to the processes of extraction and sale of natural stones. It turns out to be a kind of roulette. Artificial stones will prevail here at almost the same price.
Sandpaper does not have both of these disadvantages. Just think about how much sandpaper you can take for just the cost of one pebble and achieve exactly the same “mirror” performance over a much longer period of time.
Features of working with sandpaper
One of the main features of working with sandpaper is the method of its application. The skin is mainly used attached to a block. Making such a unit is quite simple. First you need to cut a block of the required size for comfortable sharpening. Then we cut the sandpaper to the size of the block and glue it to it with any available glue. Due to their roughness, both surfaces connect perfectly. No more manipulations are required; after 15 minutes we get to work.
Sharpening a knife with sandpaper.
Another feature of working with sandpaper is its aggressive metal removal at the first stages of use. Due to the peculiar way the abrasive grains are fixed to the substrate, they fly off the sandpaper much faster, as a result of which part of the abrasive becomes clogged with shavings and becomes greasy. Therefore, after 10 minutes of work, a 500 grit sandpaper can already polish the surface.
Table of sandpaper standards: markings and grit
GOST R 52381-2005 (Russia) | Grain size (µm) | Purpose |
Coarse-grained | ||
P22 | 800-1000 | Roughing |
P24 | 630-800 | |
P36 | 500-630 | |
P40 | 400-500 | Rough woodwork |
P46 | 315-400 | |
P60 | 250-315 | |
P80 | 200-250 | Primary grindingSmoothing the surfaceRemoving small irregularities |
P90 | 160-200 | |
P100 | 125-160 | |
P120 | 100-125 | |
P150 | 80-100 | Preparing hard wood for sandingFinal sanding of soft woodSanding old paint for painting |
P180 | 63-80 | |
Fine-grained | ||
P240 | 50-63 | Final sanding of hardwood Sanding between coats |
P280 | 40-50 | |
P400 | 28-40 | Polishing final coatsSanding before paintingWet sanding |
P600 | 20-28 | |
P1000 | 14-20 | Grinding of metal, plastics, ceramicsWet grinding |
P1200 | 10-14 | Even finer grinding, polishing Removing gloss, stains, micro-scratches |
P1500 | 7-10 | |
P2000 | 5-7 | |
P2500 | 3-5 |
Device for sharpening knives with sandpaper
Using sandpaper, as already mentioned, without attaching it to some hard surface is very inconvenient. There are many different options for how to make a device for sharpening with sandpaper, but we will look at one of the most convenient and outwardly beautiful manufacturing methods. Using a set of similar units, you can even sharpen razors.
Necessary materials
The main idea of manufacturing such a “device” is to attach emery to ceramic tiles. As a result, we will get something like a budget version of a reusable sharpening stone, since it is very easy to change the paper on it.
We will need:
- solvent (acetone is possible);
- spray adhesive;
- sheets of sandpaper of the required grain size;
- a piece of fabric (we use old things);
- rubber “bumpers”;
- smooth ceramic tiles (we select the quantity based on our own needs).
Types of sandpaper.
Sandpaper can easily be found at any automotive or hardware store. The minimum set should consist of sheets with grits of 800, 1000 and 2000.
To assemble the device, you need the longest pieces of abrasive you can find and the smoothest tile that fits the size of the paper.
Preparation and Cleaning
It is advisable to carry out this stage of work indoors; a workshop would be an excellent option. Take a rag, soak it in acetone and wipe the tiles with it. We clean all the dust from it and let the solvent dry on its own.
Remember: do not leave an open bottle of acetone in a closed room and ventilate the room after finishing work.
Attach the sandpaper
The next step, observing safety precautions, is to spray the adhesive. We process the surface of the tile and the back of the paper, then press them tightly against each other.
Try to immediately position the paper based on your preferences: it can be placed clearly in the center, leaving the edges of the tile bare, or it can be moved to one of the sides. After attaching, remove the adhesive remaining on the tile using acetone.
For greater reliability, you can press down the paper with some heavy weight, the main thing is to make sure that it does not stick to it. After two hours of waiting, you can proceed to sharpening.
One of the ways to attach sandpaper for sharpening a knife.
conclusions
Friendly advice: to increase the comfort of use, you can attach rubber strips to each tile along the edges so that you can safely stack them on top of each other, and the “bumper” will also prevent the device from sliding during operation.
If the sandpaper has become unusable, you can easily replace it: tear off the paper from the tile, treat the surface with acetone and a rag, and repeat everything again.
To have a minimal set for sharpening kitchen and household tools on hand, you will need no more than 1000 rubles, and this is with regular use for a whole year.
As mentioned earlier, 800, 1000 and 2000 grit sandpaper covers 90% of all sharpening operations and will be the most used. Larger grits can be used to sharpen thin blades, razors and, if desired, obtain a mirror-like result.
A smaller grain size will only be needed in the case of restoring a damaged, completely rusty knife.
Source: https://VashNozh.ru/zatochka/natochit-nozh-nazhdachnoj-bumagoj
How to properly sharpen knives made of different steels
There are many ways to restore the sharpness of a blade. You can sharpen knives manually or using special tools. Blade processing tools are divided into automatic and semi-automatic. With their help, damaged blades are restored, or cutting edges are simply straightened.
We will help owners of cutting tools figure out how to properly sharpen knives using any of the proposed methods.
Processing a blunt instrument on a machine
The industry produces various electric knife sharpeners.
The entire mechanism is located in the housing, which makes working on the machine completely safe. No effort or special skills are required, so any housewife can easily cope with this task.
An electric motor rotates an axis on which several abrasive wheels for various purposes are located. From rough to give the primary shape or restore the geometry of the blade, to polishing, which is used for final finishing.
Since the sandpaper has a fixed shape, the contact angle is set by guides that can be adjusted or simply changed depending on the type of tool.
To work, you need to know at what angle to sharpen your knife. To avoid mistakes, when purchasing, you should ask the seller what the parameters of the blade you are purchasing are, or take measurements on a new tool.
After setting the correct angle, we begin sharpening:
- If the cutting edge is very dull or has jagged edges, we first process it using coarse sandpaper. The knife moves with little effort from the handle to the tip. After each pass, we check the degree of sharpening to prevent excessive material removal. Then we move on to a fine-grained polishing pad;
- To restore the sharpness of a normal blade, it is enough to edit it on a polishing wheel;
Each machine comes with instructions that indicate the direction of sharpening, as well as the parameters of the sanding wheels and guides.
Is it effective to sharpen knives with sandpaper or can it ruin the blade?
Almost any garage or shed has an electric sharpener (emery). Many home craftsmen use an angle grinder for these purposes - but this does not change the essence.
So, we have a fixed electric motor with an installed abrasive wheel. It's good if there is a speed controller. However, most of these devices have fixed speeds. A picture immediately appears with a spectacular sheaf of sparks flying out from under the blade of a knife.
Two or three movements - and the edge is sharp again. This method is the biggest mistake. At high speed and strong pressure, the steel overheats, it “releases”, or even worse – annealing. It would seem that a well-sharpened knife will very soon become dull again.
The next question is how to press the blade? To the flat side of the abrasive or to the outer surface?
The correct angle of the knife blade when sharpening on sandpaper
Both methods are acceptable if the technology is followed:
- The abrasive should be fine-grained; you are not sharpening a hoe. Material – electrocorundum;
- Rotation speed no more than 150 rpm;
- The surface must be cooled. Plain water is enough. If it is not possible to continuously supply liquid to the contact point, it is necessary to install a bath under the circle. Of course, care must be taken to ensure that splashes do not enter the electric motor;
- And most importantly - at least a tool rest, or better yet, a device for controlling and fixing the angle of the blade.
Pay attention to the angle of the blade when sharpening
There are similar devices for working on a flat side. Basic principles of sharpening on an emery wheel:
- The rotation of the abrasive should be from the butt to the cutting edge;
- The knife moves across the circle in only one direction - from the handle to the tip. After each movement, the blade is inspected and time is given to cool down;
- The pressure of the blade to the sandpaper should be minimal;
- If the sharpening is double-sided, the angle of the fixing device does not change, we simply move the knife to the other side.
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Despite all the disadvantages, sharpening a knife with emery also has its advantages. Only with the help of an abrasive wheel can one obtain a so-called concave lens, when the descent planes change their angle to a more acute one as they approach the working edge.
This technology is practically not used for sharpening professional tools. Real craftsmen who know the rules of sharpening knives do it only by hand. However, if you have no claims to a samurai sword, the method is quite suitable.
Manual sharpening methods
As a rule, not everyone has an electric knife sharpener in their kitchen, so let’s look at several options for manual sharpening.
First, watch this detailed video: How to sharpen a knife with a whetstone. Having mastered simple sharpening techniques with a whetstone, you can always correct your knife without contacting a specialized service center.
Let's start with the classics - touchstone
Knives have been sharpened this way since their invention. A whetstone is a flat, abrasive stone with a fine grain. Initially, natural materials were used, today sharpening stones are factory-made and have excellent characteristics.
The most common way is to hold the blade at a certain angle and make circular movements. An indispensable condition is that the whetstone must be wet. Despite all the primitiveness, the sharpening turns out to be of quite high quality.
No matter how authoritative this method is, it is almost impossible to keep the blade in a fixed position. Therefore, there are various devices that hold the blade at a certain angle.
There is also small-scale mechanization. Only the concept is different - the knife is fixed on a stand, and the emery moves across the blade with the help of a directed rod.
Such devices are widely made by hand, and they work no worse than factory ones.
The only drawback of such devices is that the work is done too slowly, and the surface of the blade is either straight or faceted. For the vast majority of blades, this is more than enough.
How to sharpen knives with musat, and what is it?
Musat, or rule, is a sword-shaped rod with a handle. The surface of the tool can be metal, ceramic or sprayed. There are even diamond musats (of course, we are talking about diamond chips).
In one form or another, you will find this device in any professional kitchen. Recently, it has become fashionable to keep musats in the house.
By and large, this device should not be used for sharpening, but rather for finishing straightening the blade. Chefs refresh their cutting edges from time to time during the working day, nothing more.
You just need to do it correctly:
Its tip should rest against something, preferably a wooden surface. The knife is pressed at an acute angle by the handle to the rod (in the area of the musat handle).
Then, with an energetic movement, the blade is lowered to the tip of the tool, while simultaneously pulling the cutting edge to the nose. Such movements should be made by alternately changing the side of the blade.
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For a professional, the sharpening process resembles a circus show. You will not be able to sharpen a dull knife with this device. But it’s easy to properly straighten a cutting edge.
Several ways to edit a knife with musat in this video
How to sharpen knives against each other correctly
Sometimes a situation arises when there is no sharpening device at hand, but you urgently need to correct a dull blade. In this case, you can sharpen the knife on the knife.
The cutting edge of one knife is straightened (or even sharpened) on the back surface (butt) of the second. Of course, this method is only suitable for massive long blades.
After performing one and a half to two dozen energetic movements, you will restore the sharpness of the edge for a while. This method cannot be considered a full-fledged sharpening.
When sharpening a knife, everything matters: effort, tilt, beginning and end point of movement. and it all depends on the quality of the steel.
Damascus steel knife
This name makes any connoisseur of edged weapons start to feel a rapid heartbeat. Meanwhile, Damascus knives also tend to become dull. Unless, of course, they are under glass in a home collection.
There can be no talk of any electric sharpeners. The blade consists of alternating soft and hard grades of steel, which with such rough intervention will simply lose their unique properties. Therefore, only hand sharpening.
Before starting work, you need to understand how hard the material is. This can be determined by looking at the sharpening angle. The sharper it is, the harder the steel.
Knife blade sharpening technology
Whatever material you use to sharpen, Damascus knives are sharpened only along the blade. This is a golden rule; neglecting it will simply ruin the blade. And it is best to sharpen this unique steel with a fine-grained whetstone. Moreover, you need to start from larger grains, gradually moving to “velvet”.
If there are nicks on the tip, you will have to grind off the entire length of the edge.
In this video, the master gives an example of sharpening Damascus steel knives, without claiming that the method is ideal.
Damask steel knife
No less eminent fellow in terms of elite blade. feature - the highest hardness of the alloy. With the tip of a damask knife you can cut a steel nail or corner.
Therefore, sharpening such a blade should be taken very seriously. Damask steel is sharpened on a wet whetstone, first with coarse grains (the so-called roughing stone). Then we move on to sharpening (fine grit), and bring the blade to the ceramic surface.
The process is long, but the result is worth it.
Watch the video: Sharpening a damask knife using a hand sharpener. At the end of the video there is a demonstration of the tip of the blade.
A selection of videos on the topic - how to sharpen a knife with a whetstone
How to properly sharpen a knife on a stone. A guide for beginners.
Resuscitation of a rusty knife, or sharpening the blade on stones from a Japanese master
Watch in this video - how to sharpen a knife on a whetstone to razor sharpness?
And at the end of the lesson, the master will shave himself with this knife! How to properly sharpen knives with a whetstone - video example
Source: https://obinstrumente.ru/ruchnoj-instrument/kak-pravilno-tochit-nozhi.html
How to properly sharpen a knife on a sharpening machine
It is simply impossible to describe all the nuances of how to properly sharpen knives in one article, but this is not always necessary. Especially if an ordinary kitchen knife needs sharpening or you are just a beginner who needs to start somewhere.
- In fact, sharpening a kitchen knife to a sharp point at home can be done easily and quickly. But the difficulty is that this must be done in such a way that the sharpness of the blade is preserved for a long time, and at the same time too much steel is not removed from the blade.
In this material we will try to simply and clearly tell you how to properly sharpen a knife with a whetstone. After all, this method is not only basic and accessible to everyone, but also the most effective. In addition to step-by-step instructions for sharpening and finishing, here you will find a selection of training videos and an overview of alternative methods - from sharpening systems to the bottom of a ceramic plate.
A little about choosing stones
Sharpening stones come in the following types:
- Ceramic;
- Diamond;
- Natural;
- Japanese water stones.
If you wish, once you gain experience, you can buy some solid and expensive diamond stones or Japanese water stones. However, it is better to start with ordinary ceramic bars (such as “Boats”), which are sold in every household goods store. They are wear-resistant, durable and affordable. The only drawback is their uneven abrasion.
Here are tips to help you find the right assistant:
- What size should the block be? Ideally, it is 1.5-2 times longer or at least not shorter than the knife blade. The width and shape of the bar is not important.
- When purchasing a block, make sure it is flat and free of chips.
- To start, you can buy one medium-hard all-purpose whetstone. But if you wish, buy one block with two sides of different grain sizes or two stones with a large and half the grain size. In the future, a couple more stones may be added to your collection.
- It's best to try to get a couple of Soviet-made donkeys, say, at flea markets or from your grandfather. Bars marked “Made in the USSR” have uniform-sized grains and high-quality binding material.
To bring your knife to razor sharpness, in addition to sharpening stones, you can also buy GOI abrasive paste, which we will also talk about working with.
7-step instructions for sharpening and finishing a kitchen knife
So, in sharpening a knife, one goal is to remove enough metal from the blade so that the cutting edge becomes sharp again. You need to start work with a coarse-grained abrasive and finish with a fine-grained one.
It is important to remember the following principles of sharpening knives:
- The most important thing is to choose the optimal sharpening angle and maintain it along the entire cutting edge while sliding along the block.
- Movements should be smooth, without pressure.
- All bars must be moistened with water, or better yet, with a soap solution: before sharpening (so that the blade glides better and metal dust does not clog the pores), during the process (to remove the resulting suspension) and at the end, to clean the bar.
And one more important tip - the first time it’s better to practice on a knife that you don’t mind ruining. Especially if your main knife is too good and expensive. Well, let's start practicing.
Step 1. Rinse the stone with water, and then run over it, say, with a sponge with a drop of dishwashing liquid.
Step 2. Next, sit down at the table and place the stone on a wooden board, for example, a cutting board. You can place a towel under the stone. For some it is more convenient to place the block perpendicular to themselves, and for others at an angle of approximately 45 degrees. Over time, you will understand how it is more convenient for you to work.
Step 3. Now you need to decide on the sharpening angle and fix the position of the knife. What should the angle be? The general principle is that the smaller it is, the sharper the blade, and the larger it is, the longer the blade retains its sharpness.
- Regular kitchen knives are sharpened to an angle of 40-45 degrees. If you are sharpening a fillet knife (designed for cutting thin pieces of fish, poultry and meat), then you should sharpen it sharper - at an angle of 30-40 degrees. The selected value must be divided by 2, and then we will get the angle that should be between the blade and the surface of the block. That is, to sharpen a blade at 45 degrees, you need to sharpen each side at 22.5 degrees to the sharpening surface.
A simple technique shown in the photo below will help you fix the knife at an angle of 22.5 degrees.
- Remember, you should try to stick to the chosen angle throughout the entire work.
Step 4. Place the knife across the block so that the upper edge of the handle is above the lower edge of the stone. Holding the handle with one hand and the blade with the other, we begin to slide along the block away from ourselves along the trajectory shown in the picture below.
Watch a short and clear video:
- The point is that the cutting edge sliding along the stone should always be perpendicular to the direction of movement.
- At the bend of the blade, the knife handle needs to be slightly raised to maintain the selected angle.
- Remember also that you can’t put pressure on the blade, but you shouldn’t give it any slack either.
Thus, you need to pass the blade along the stone about 40-50 times, namely until a “burr” (burr, microsaw) appears along the entire length of the cutting edge. Its appearance will tell you that the excess metal has worn out and there is no point in grinding further. Then you need to turn the blade over and repeat the same steps. Clearly in the video:
- A burr is a small roughness that is difficult to see, but can be felt by carefully running your finger along the edge of the blade (but not along the edge, so as not to cut yourself).
Burr of a sharpened knife
During operation, a suspension will appear on the blade - metal dust, which must be periodically washed off with water.
Step 5. So, the burrs have appeared, now we proceed to finishing. To do this, we repeat the same manipulations on a stone with half the grain size. An alternative finishing method is using musat.
- Musat is a steel rod of oval or round cross-section with longitudinal notches. It is only suitable for editing and maintaining sharpness, but not for sharpening a knife. It is recommended to edit the knife with musat every time before and after work.
How to sharpen a kitchen knife with musat can be seen in the following video master class from the respected knifemaker Gennady Prokopenkov, who, by the way, specializes in making kitchen knives.
Step 6. If desired, you can bring your knife to a razor sharpness. To do this, take any leather or leather belt, treat it with GOI, Dialux or any other abrasive paste, and then do the same steps, but only in the direction from the cutting edge.
Step 7. Finally, we check the quality of sharpening. This is done very simply. It is enough to cut a tomato or cut paper. If you wanted to achieve razor sharpness, then you should try to shave the hair on your arm. The sharpest knives can even cut hair, as shown in the photo below, but in the kitchen such sharpness is not required for the most ordinary knife.
Alternative sharpening methods
If your kitchen knife is a simple and inexpensive “hard worker” and/or you just don’t want to delve into the “knife culture”, then we recommend using an electric sharpener, a roller knife or a sharpening system for sharpening at home. What are their pros and cons?
- An electric sharpener sharpens knives perfectly and quickly, but even the highest quality models remove too much material from the blades, thereby shortening their service life. Another disadvantage of an electric sharpener is that a good device costs more than $200.
- A roller knife is an inexpensive and easy-to-use option. With its help, you can quickly sharpen a kitchen knife, but, unfortunately, the sharpness of the blade will not last long and the knife will deteriorate over time. The most trusted tool among roller scissors is the one from Fiskaris (pictured). Do not confuse a roller blade with a V-shaped blade. The latter is an option for the most frugal.
- Sharpening systems are good because they allow you to more accurately set and maintain an angle. There are different types of such sharpeners - with blade fixation (manufacturers DMT and Lanski) and with fixation of the stones themselves at a certain angle (Spyderco Triangle Sharpmaker). Separately, we can highlight a sharpening system in which you can select the desired angle and control the position of the knife - this is the Edge Pro Apex Knife Sharpening System. Each system has its own pros and cons. For example, on sharpeners with a fixed blade it is inconvenient to sharpen wide chef knives, but on a triangle from Spyderco the knives are straightened rather than sharpened, and you can only choose an angle of 30 or 40 degrees. However, for kitchen knives these are the angles that are needed, and using a triangle is very simple. A detailed review and operating instructions for the Spyderco sharpener can be seen in the following video.
Digital ruler for machine
What are the disadvantages of Apex Edge Pro? Perhaps this is just a high price - $245. However, to sharpen kitchen knives, you can buy a Chinese copy of this sharpener (for example, on Aliexpress).
There is another clever way to sharpen a knife at home - using a rough mark on the bottom of a ceramic mug or plate. The principle of operation is still the same - maintaining the angle, smooth movements, maintaining the cutting edge (cutting edge) perpendicular to the direction.
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Source: http://ooo-asteko.ru/kak-pravilno-tochit-nozh-na-tochilnom-stanke/
Sharpening and finishing the tool with sandpaper (sandpaper)
With just sandpaper and a simple homemade tool, you can make your tools razor-sharp in minutes.
Do you wait to sharpen your tools until they are completely dull? There is a simple and cheap way to return them to their former sharpness.
We are confident that with its help you will always keep the blades of your planes and chisels in excellent condition. This is worth doing, if only because sharp tools make the job easier, more accurate and much safer.
If the chisel cuts wood easily and you don't use much force to do it, it's unlikely to break off, damaging the surface or your hand. Using the correct sharpening technique, you will not spend much time on it. Although sharpening time depends on the hardness of the steel and the condition of the cutting edge, on average it takes no more than 10 minutes to get a dull chisel razor-sharp.
Simple tools allow you to achieve great results
There is a huge selection of sharpening tools, ranging from natural, synthetic and diamond whetstones and stones to electric horizontal and vertical sharpening machines. However, sandpaper has several advantages over all these means.
It grinds metal effectively, produces flat edges, and is inexpensive. For best results, use black wet/dry sanding paper with silicon carbide abrasive.
Silicon carbide grains are harder than other abrasives used in abrasive papers, such as aluminum oxide or garnet, so they grind steel better and last longer. Stock up on sheets of paper with gradually decreasing grain sizes (100; 150; 220; 320; 400 and 600 grit) and you can make all the hand tools in the workshop sharp again. To finalize the cutting edges, you will need a little fine abrasive powder.
We prefer a ready-made mixture consisting of oxalic acid, feldspar, baking soda and a few proprietary ingredients.
The work requires a hard and flat surface, for example, a piece of MDF board, on which sheets of paper are placed. If the surface is too smooth, such as glass or plastic, and the paper starts to slip, wet it with water.
Although not necessary, you can better evaluate your work using a magnifying glass, which is what photographers use to look at prints and negatives. You can buy such a magnifying glass in photographic stores.
And finally, since sharpening with sandpaper requires the precise angle of the blade to be maintained, we have developed a simple, yet durable and reliable device made from hard maple wood that allows you to confidently control the entire process.
When working with it, the blade is held exactly at a given angle, without tilting from side to side, and the chamfer turns out to be perfectly flat. However, it allows for side-to-side movements to prevent the abrasive paper from wearing down in one area.
Before you start sharpening, make yourself the same device.
Making a tool sharpening device
The device shown in the figure is suitable for chisels and plane blades with a length of at least 75 mm with a sharpening angle of 25°. You can make several of these to sharpen at other angles.
First, cut the base A from hard maple wood with an allowance for length. The workpiece should have dimensions of about 13x76x255 mm. Install a groove disk into the sawing machine and cut out a tongue 5 mm deep and 45 mm wide at a distance of 19 mm from the rear edge (step 1 in the figure “Making the base”).
Then install the rip saw blade and tilt it at an angle of 25°. Using double-sided tape, attach the workpiece to a support board made from scraps, the dimensions of which should be larger than the workpiece. Position this assembly (step 2) and file the bevel onto the workpiece.
Return the blade to a vertical position and saw the workpiece to a final length of 190 mm.
Make a holder B from a workpiece measuring 19x45x255 mm. Tilt the saw blade at an angle of 25° and, attaching the holder to the supporting board, file the bevel (step 1 in the figure “Making the holder”). Place the disc in a vertical position and saw the holder to a length of 190 mm. Drill two counterbore holes on the underside (step 2) to install the screws.
The centers of the holes are located 32mm from the ends of the holder, first make the counterbores and then drill a 5mm hole in the center of each. Install a groove disk into the sawing machine and, using a transverse (angular) stop, make a recess 102 mm wide and 1.5 mm deep (step 3). This recess will help secure the tools to be sharpened at right angles to the work surface.
Saw out the clamp C and drill holes for the screws. Place the holes 32 mm from the ends of the clamp, in the middle of its width. Make a handle D and glue it to the clamp. Once the glue has dried, assemble the fixture by adding screws, washers, and wing nuts. Apply a little wax paste to the tongue of the base so that the holder moves easily from side to side.
Photo 1 How to make a device for sharpening and finishing
Photo 2
Related link: Sharpening tools using other materials
Dull and jagged blades will become shiny and sharp again
Take a dull chisel or a new one like the one shown in the photo and watch the amazing changes. Place the jig on a sheet of 100-grit sandpaper. Insert the chisel blade chamfer down into holder B under clamp C.
Align the blade along the edge of the recess in the holder so that the bevel touches the sandpaper (Photo A). Tighten the wing nuts firmly to secure the chisel.
The blade is now positioned perpendicular to the work surface, and its tip protrudes slightly beyond the underside of the base.
Place the tool so that its base and the chamfer of the blade rest on the sandpaper.
Hold the edge of the sheet with one hand and grasp the holder with the other (photo B). Move the holder along with the chisel away from you, pressing the bevel against the paper. Then return to yourself again, loosening the pressure a little. After making several such movements, remove the holder from the base and inspect the chamfer of the blade (photo C). It doesn’t matter whether a new chisel is being sharpened or an old one, the tasks are the same. It is necessary that the entire chamfer is evenly covered with thin marks parallel to the cutting edge.
If this requires a few more movements, move the base of the tool a little to use an untouched area of the sheet. Remove the chisel from the tool, press it against the sandpaper with the top plane (back) (photo D) and make a few movements from side to side. And again the same goal - to achieve a uniform pattern formed by thin marks.
Many new chisels have a concave bevel, and sometimes it takes a little more time to get it flat. Gradually reducing the grit of the sandpaper, repeat these steps on both edges of the blade so that they are processed equally.
Use a loupe to examine the surface to determine when to change to a finer abrasive. Of course, you can continue to reduce the abrasive grain size down to 2000 grit, but we suggest stopping at 600 and starting to fine-tune the cutting edge. The chisel will be sharp enough to handle any carpentry task.
How to fine-tune a tool after sharpening
When finishing, the tiny scratches left by the sandpaper are removed, and both surfaces that form the cutting edge become polished like a mirror. We polished our chisels on a leather belt rubbed with green chromium oxide paste (the domestic analogue is GOI paste).
Instead of a belt, you can take a piece of any tanned leather, for example, the top of an old boot, and instead of a polishing paste, use any cleaning powder used in everyday life. Excellent results can be achieved even easier.
Apply a pinch of cleaning powder to a flat piece of dense wood such as maple or a piece of MDF board.
Then use the tool again. Then, taking the chisel out of it, polish the back side (back). The fine abrasive particles contained in the cleaning powder will remove most scratches and polish the steel to a shine.
Sharpened chisels should be stored carefully so that nicks do not appear on the cutting edge. When you have finished finishing the planer blade, immediately insert it into the block and do not extend the cutting edge below the sole unless you intend to immediately begin planing.
Once you have all your cutting tools in order, develop the good habit of always keeping them sharp by regularly sharpening them. Then you don’t have to start working with 100 grit abrasive, but can immediately take paper No. 320 and move on to smaller numbers.
Note: To sharpen or not to sharpen?
Any sharpening method using sandpaper creates a flat bevel on the blade. Each time you have to grind the metal off the entire chamfer. This doesn't become a problem if you sharpen regularly to keep your tools sharp.
If you use an electric sharpener at the first stage of sharpening, the abrasive disk forms a concave chamfer (see figure).
Of course, you can do it this way and then continue sharpening on paper. But we recommend that you always sharpen tools only on paper, since a concave chamfer usually results in a less stable cutting edge.
Source: http://kak-svoimi-rukami.com/2013/11/zatochka-i-dovodka-instrumenta-nazhdachkoj-nazhdachnoj-bumagoj/
Tricks to help sharpen a chisel with your own hands
Sharpening chisels at home can be done with equal success using factory-made machines and homemade devices. A standard set for processing the blade of a carpentry tool includes an abrasive for initial work, grinding products for finishing, and a mandrel-fixer.
General rules for sharpening chisels
To sharpen the blade of carpentry tools, you will need to rigidly fix the product at the desired angle to the abrasive surface. Moreover, it is necessary to strictly maintain the angle both in the longitudinal and transverse directions. Two types of sharpening mandrels are used for fixation:
- equipment used to process the working plane of a chisel on the abrasive wheel of an electric sharpening device;
- manual mandrel for sharpening tools on whetstones and sheet abrasives.
Chamfer processing of carpentry parts is carried out using a grinding stone with a grain of 300-400 microns, followed by the procedure of finishing the cutting edge with an abrasive of 50-80 microns. To sharpen chamfers, both electric sharpeners and hand tools are used. At this stage, it is important to achieve equal angles of inclination on both sides of the canvas.
Finishing is carried out exclusively by hand, during which the cutting edge is extremely sharp and micro-irregularities and scratches are eliminated. The purpose of finishing is to achieve geometric accuracy of the working surface of a wood carving chisel.
Tools and materials for sharpening
To adjust the sharpness of a wood carving chisel, various types of tools and materials are used:
- sharpening machines of vertical and horizontal types;
- sharpening stones;
- bars with sandpaper;
- sheet abrasives;
- cloth polishing resources and felt bases.
Sharpening of chisels can be done using a machine
To fix the tool use:
- metal models of factory-made mandrels with angular adjustment;
- homemade wooden versions of devices in which the angle is formed using wedges.
The fixing device provides two functional components in the form of a carriage for moving along the abrasive surface and an inclined platform with a clamp. The latter is pre-set at a given angle.
Sharpening technique
In order to properly process the working surface of the chisel, it is recommended to use special products that have both grinding and polishing properties. Most often, preference is given to sharpening water stones or fine-grained sheet abrasives on a water-resistant basis.
Preparatory stage
Sharpening stones are pre-soaked in water. During the sharpening process, the liquid helps create a viscous grinding suspension, as it mixes with abrasive dust.
Angle editing and chamfering
The wood chisel is fixed at a given angle; according to the standards, the inclination is about 25°. This parameter may vary depending on the purpose of the joinery:
- The chamfer of the tool for slotting work is sharpened at an angle of 27-30°;
- for accurate trimming of wood with the removal of thin chips, a correction of the working surface by 20-22° is required;
- A universal chisel for most woodworking is sharpened at an angle of 25°.
It is worth considering that the sharpening angle of the chisel also depends on the parameters of the blade: thick blades provide a relatively steep bevel.
If you need to form a chamfer with significant adjustments to the sharpening angle, you should start working on a sharpening machine. To easily correct the sharpness of the cutting edge, perform the following steps:
- process the chamfer on the abrasive stone until visible damage is completely eliminated. In this case, the specified slope must be maintained both in the longitudinal and transverse directions;
- check the cutting edge for geometric evenness. Here it is necessary to achieve strict perpendicularity of the line in relation to the canvas. Otherwise, you will have to straighten the edge on the sharpening stone, after which the working surface is ground again to an ideal sharpness.
The angle for sharpening chisels should be about 25°
If it is necessary to adjust the sharpness of a chisel with a bevel on the edge, grind it with a stop, lifting the cutting blade up within 5°.
Features of cutter processing
The work is carried out taking into account the following recommendations:
- First, the flat side of the canvas is processed. Movements are performed along the same trajectory along the entire length of the stone;
- then change the position of the chisel and work with the main working surface of the wood carving tool. Movements should be uniform, without jerking, but quite fast. In this case, it is necessary to maintain the desired angle of inclination;
- after the coarse-grained abrasive begins to leave scratches on the surface of the cutting blade, switch to a medium-grained stone. Next, if necessary, use an abrasive material with fine grain;
- when sharpening the chamfer, 1.5-2 mm is allocated, the perimeter is made at an acute angle of 5-7°. The chamfer is formed in just a few movements along the entire length of the stone.
It is noteworthy that the process of sharpening a wood chisel takes no more than 10 minutes if a simple correction of the sharpness of the carpentry is performed. If there are significant irregularities, chips or other defects on the surface of the tool, sharpening will take up to 1 hour or more.
Final polishing
The process of sharpening a chisel for wood carving is completed by straightening using various devices. Most often, they use a leather belt rubbed with GOI paste, or a kitchen cleaner on a flat wooden surface. The blade can also be polished on a felt wheel using polishing paste.
Chisel sharpening machine
Various models of machines and devices for sharpening chisels are presented in specialized stores in Moscow and other cities. Since the device provides a simple design, they often make equipment for correcting the sharpness of carpentry tools with their own hands.
To make a homemade sharpening machine, make a blank for the base with dimensions of 13x76x255 mm. The work to be done next is as follows:
- Moving 19 mm from the back line of the workpiece, cut out a 5x45 mm tongue and groove. To do this, use a device with a cutter to form grooves.
- Using a slitting disc, a bevel is made at an angle of 25°.
- The workpiece is fixed on the base surface. Double-sided tape is most often used for these purposes.
- A vertical cut is made to set the final length of the device for sharpening chisels; the size of the product is 190 mm.
Chisel sharpening machine
To build a trolley holder, use a blank with dimensions 19x45x255 mm:
- a bevel is made on the workpiece at an angle of 25°;
- vertically trimmed within a length of 190 mm;
- on the bottom surface, moving 32 mm from both edges, drill 2 holes;
- Using a groove disk, a 102x1.5 mm recess is formed to fix the chisel.
Next, a clamp is cut out, and holes for screws are drilled in a selected area in the middle of the workpiece at a distance of 32 mm from each edge. Then the handle is glued to the clamp. The final assembly of the structure is carried out after the fixing composition has completely dried.
For normal operation of the machine, the base tongue is treated with a wax composition. This also helps to optimize the sliding level of the holder.
How to sharpen a semicircular chisel?
To correct carpentry tools with a semicircular cutter, a wooden block with an edge that follows its shape is used.
Necessary materials:
- silicon block;
- wood blank;
- abrasive powder;
- sandpaper with a grain size of 400, 800, 1000, 2000 microns;
- a piece of leather for polishing.
Stages of work:
- Wet the silicon block in a soap solution. Next, they begin to work, performing sideways movements, pressing the chamfer to the touchstone at the desired angle until a burr is formed.
- Next, a wooden block with a rounded edge, which is decorated with sandpaper, is used. During the processing process, the abrasive is changed to an analogue with a small denomination.
- At the end of the process, the cutting edge is polished and straightened using leather.
If you sharpen the chisel correctly, ensuring the appropriate chamfer angle, the quality of the carpenter's work improves. Moreover, not only the accuracy of the cut, but also the level of productivity of the woodworker depends on the sharpness of the working surface.
Source: https://stroypomochnik.ru/zatochka-stamesok-01/
Secrets of proper sharpening of tools on an electric sharpener
Every person in everyday life encounters the use of cutting tools. The most common of them are knives and scissors, which are found in the kitchen of any home. But to perform a wider range of household work, the list of cutting tools used is significantly expanded. But all these tools have one common problem - they need to be sharpened periodically. And if this is done incorrectly, then you can forget about quality work.
What is the best way to sharpen tools?
Many different devices have been created for sharpening tools, from purely household to professional ones. Effective use of each of them requires an individual approach and level of skill. Moreover, if with household sharpeners the maximum risk from improper use is that nothing will simply be sharpened, then with professional sharpeners you can permanently damage the cutting surface in a split second.
The most common sharpening devices include:
- Electric sharpeners. They are characterized by a high price and lead to rapid wear of the blade.
- Musat. Usually included in knife sets, but is no longer intended for sharpening, but for straightening the blade.
- Roller sharpener. It has a low cost, does not require qualifications, but does not allow you to achieve the proper sharpness.
- Ceramic bar. It is inexpensive, but takes time to sharpen well.
- Diamond coated stone. It costs more than ceramic, but speeds up the work process.
- Electric sharpener or sandpaper. It is not cheap, but it is the most versatile and effective option for sharpening the cutting surfaces of any tools.
How to sharpen knives using sandpaper
Sharpening knives using emery requires the performer to have certain experience and qualifications. Therefore, a novice user should remember a number of rules for quality work:
- It is necessary to strictly observe the sharpening angle of the device blade. Typically it is in the range from 200 to 450 depending on the intended purpose of the knife. This angle must be maintained along the entire length of the cutting surface. For this, special devices are used.
- You need to choose the right type of wheel for sharpening. It depends on the condition of the blade. For rough work, it is recommended to use coarse-grained wheels. The final grinding is done on a fine-grain wheel.
- At high speeds of the abrasive wheel, there is a risk of overheating the tool blade, as a result of which it will become unsuitable for further use. Therefore, it is better to limit the number of revolutions or periodically cool the knife.
Using a sharpener for straightening cutting devices
A separate operation that accompanies the process of sharpening tools is the editing of cutting devices. Its goal is to give the blade an ideal sharpness, subject to the obligatory preservation of the sharpening angles. The steel is also polished at this stage.
Editing is the most critical part of the work, during which mistakes are most often made. This is due to the fact that a thin part of the metal is exposed to the abrasive. As a result, the risk of overheating or damage increases significantly.
Therefore, it is recommended to edit a tool, as opposed to sharpening, by directing the blade along the rotation of the grinding wheel. The abrasive used is fine-grained and only at low speeds.
But for beginners, it is still recommended to edit the cutting tool using a ceramic stone or fine-grained sandpaper.
By following these recommendations, you can maintain your cutting tool in perfect condition at no extra cost. The main thing to remember is that any sharpening method, especially using an electric sharpener, requires mandatory compliance with safety requirements.
Source: https://TehnoPanorama.ru/instrumenty/sekrety-pravilnoy-zatochki-instrumentov-na-elektrotochile.html
How to sharpen your kitchen knives to razor sharpness yourself
When preparing food, you must use sharp knives. Of course, it’s easier to contact a specialist who can sharpen a knife correctly quickly and for little money, but you can do it yourself.
It is necessary to sharpen a knife according to certain rules, otherwise you can damage the blade.
Correct knife sharpening angle
When sharpening kitchen knives, it is important that the objects are in a certain position in relation to the work surface. To do this, you need to choose the correct sharpening angle.
This parameter depends on many factors, for example, the type and level of strength of the metal from which the blade is made, as well as the purpose for which this tool is used. So, the degree of sharpening for different types of knives:
- scalpel and razor blade - from 10 to 15 degrees;
- vegetable, meat and fish knives - from 15 to 20 degrees;
- other chef's utensils - from 20 to 25 degrees;
- hunting blades – 25–30 degrees.
It is important to choose the right sharpening angle; this is necessary to achieve the desired sharpness of the kitchen appliance.
What grit size is needed for sharpening knives?
When sharpening blades, special stones are used. Their surface is an abrasive consisting of grains of different sizes. The grain size of the stone depends on this indicator. Devices for adding spice are divided into the following groups:
- the most coarse-grained (especially coarse material);
- regular coarse-grained;
- medium grain;
- fine-grained (delicate abrasive);
- micro-grained (material of increased fineness).
How to sharpen a knife correctly? A good master knows that using only one type of stone is ineffective. According to the rules, sharpening is performed alternately, moving from coarse-grained and rough stones to delicate, thin stones.
How to sharpen knives on a sharpening machine
Using a machine is considered an effective way of sharpening, however, the mechanism is cumbersome, and for this reason not every home has it. But if you have the opportunity to use it to sharpen dull kitchen appliances, you should know some of the intricacies of this work:
- sharpening on the machine is carried out at high temperatures, so it is necessary to set the minimum number of revolutions so as not to damage the blade;
- the blade must be pressed tightly against the sharpening surface, and the movements when sharpening must be smooth;
- When the cutting surface is sharp, it is important to keep the part being sharpened at an angle of 25–30 degrees relative to the grinding wheel.
Please note that you will need a lot of time to work. In addition, those who do not have sufficient experience in this matter should not undertake sharpening on a machine.
How to properly sharpen knives with sandpaper
If you have some experience and know how emery works, sharpening knives will not be difficult for you. So, when sharpening blades on sandpaper, adhere to the following rules:
- When applying the blade to the abrasive, you should not apply large mechanical forces;
- the trajectory of rotation of the abrasive should be in the direction from the butt to the edge;
- the knife on the emery is moved across the circle, smoothly moving from the handle of the device to the tip of the blade;
- When sharpening on both sides, you cannot change the angle of fixation of the blade, you just need to move it to the other side;
- At the end of the work, straighten the knife with a block, musat or sandpaper.
Of course, real craftsmen prefer sharpening by hand, which allows them to achieve maximum effect. But if we are not talking about giving the blade a scalpel sharpness, but simply making it quite sharp, using sandpaper will achieve decent results.
How to sharpen kitchen knives with a sharpener
Today you can purchase special devices for sharpening knives - these are blade sharpeners. These devices are either mechanical or electrical. If you are not very experienced or have not tried sharpening knives at all yourself, it is better to use the electric option.
This sharpener independently selects the sharpening angle, and is used to sharpen any type of household blade. The work is done like this:
- Set the required mode.
- Place the blade in a special hole.
- Apply a little pressure to create tight contact between the blade and the sharpening surface.
Once you follow these steps, you no longer have to worry about ruining your knife. The sharpener will do the work on its own, and you will get a wonderfully sharp blade. This is the best way to achieve the desired sharpness of a kitchen appliance at home.
How to use a round disc knife sharpener
There are various devices for sharpening knives, including sharpeners with round discs. The difference is that the sharpening material in this case is a special rotating roller that grinds the cutting surface at an angle of 45 degrees.
The main advantage of such devices is that after sharpening there is no burr left on the blade, and the work is done simply. In addition, tools sharpened with roller sharpeners stay sharp much longer than with V-shaped tools.
Most often, such sharpeners are suitable not only for knives, but also for scissors.
- So first make sure you select a cavity to sharpen your knife.
- Take the sharpener in your left hand and the knife in your right.
- Place the knife blade in the area of the handle between the discs and forcefully draw it to the tip.
- Repeat the same thing several times.
- Be careful not to cut yourself.
How to sharpen Damascus steel knives
Damascus steel knives have been popular at all times; they are considered the most durable, and their sharpness cannot be compared with anything else. But even this material tends to become dull.
It is important to know that no electric sharpeners can be used here, only manual processing is needed. When sharpening a Damascus steel knife, you must adhere to the following principles:
- First, determine the strength of the metal. This can be done by paying attention to the sharpening angle; the stronger the material, the sharper it will be.
- Use fine-grained abrasives, gradually moving to micro-coatings.
- Sharpen the blade only along the cutting surface.
- If there are nicks, the edge must be ground along its entire length.
- If the bevels need to be polished, this must be done before the cutting edge is sharpened. If you process an already sharpened blade, the tip may simply become rounded.
If you are not sure that you will do everything correctly, it is better not to risk it and contact a specialist.
Is it possible to sharpen a knife without a stone?
It happens that a knife needs urgent sharpening, but there are no suitable tools. But don’t worry, you can solve the problem in the following ways:
- sharpen a dull knife on the blade of another cutting device;
- sharpen on the raw edges of the bottom of a plate or mug;
- sand the blade with sandpaper, processing only one side;
- take any stone that you find on the street and sharpen it in the same way as you do with a whetstone.
This will allow you to briefly sharpen a dull device, but such methods cannot be called full-fledged sharpening. Remember that it is better to reserve these measures for extreme cases and not to use them constantly, otherwise the blades will quickly become unusable.
How to sharpen a knife on a knife
What to do if the blade becomes dull and you don’t have a whetstone or an electric sharpener at hand? Sharpen your knife on your knife! Perform this procedure like this:
- apply the cutting surface of the dull blade to the back of another knife;
- take the tools so that you sharpen “from yourself”, that is, the cutting edges should be directed to the sides;
- perform 10-15 vigorous strokes, rubbing one blade against the other.
This will briefly “revive” a dull knife, however, such a procedure is not a full-fledged sharpening.
How to sharpen a knife to razor sharpness
Almost any blade can be given a razor sharpness. To achieve this, use one of the methods below:
- Treat the surface with GOI paste and a piece of genuine leather, after removing nicks using a fine-grained stone. Remember that you need to carry out finishing work, moving from the handle to the tip, without changing direction, and keep the blade at an angle.
- Grind down the edge until the serrations are fine, and then grind the other side of the blade in the same way. This will add some spice, but not for long.
- Use ceramics, for example, turn a plate upside down and sharpen the device on the untreated areas on the bottom that are not covered with glaze.
When working, be careful not to get injured in the form of a cut or damage the blade.
How to sharpen a serrated knife
If you have serrated knives in your kitchen, then you need to know that these utensils cannot be sharpened with regular sharpeners. To make this version of the cutting surface sharp, you need to do the following:
- Prepare a special tool for serrated blades, namely a cone-shaped sharpening rod, preferably made of ceramic.
- Determine the side on which the beveled teeth are located and sharpen this part of the blade.
- Place the sharpening device at an angle to the beveled part of the blade.
- Sharpen each depression with several movements, moving the blade in the direction “away from you.”
- Remove the formed burrs using sandpaper or the same rod, but do not press on the surface, but act gently.
- Sharpen the smooth side of the blade with a suitable tool.
Remember not to use a rod to trim the serrated surfaces on the side of the blade where they are missing, otherwise you will ruin the knife.
Source: https://hoznauka.ru/poleznye-sovety/kak-pravilno-tochit-nozhi.html
How to sharpen knives, axes, metal drills using sandpaper
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.
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.
How to sharpen a tipped pobedite drill bit
A pobedite drill bit can also become dull. A dull drill overheats during operation, drills poorly and makes a loud squealing sound. Of course, you can change the drill by buying a new one, but it’s better to save money and sharpen it yourself.
To do this you will need a sharpening machine (electric sharpener) with a diamond stone and coolant. An ordinary emery stone is not suitable for sharpening a Pobedit drill. Before you start sharpening, make sure that it is possible in principle. To do this, measure the height of the cutting part of the drill.
https://www.youtube.com/watch?v=t_an94cXinQ
When the height of the cutting part of the drill, i.e. soldering, is about 10 mm, sharpening is possible.
Don’t forget: the harder the material, the lower the sharpening speed should be. The angular speed (the number of rotations of the stone) when sharpening a pobedit drill should be reduced, regardless of which tool is used for sharpening.
Sharpening the drill is done by briefly touching the drill to the emery stone. A pobedit drill is sharpened quickly; as a rule, you only need to slightly correct the slick edges, so you should carefully monitor the process so as not to cut off excess from the working surface of the drill.
It is recommended to sharpen tipped drills in the same way as simple small-diameter drills, i.e. The back surface should be sharpened flat. In this case, the back surface should be sharpened as shown in the photo, grinding the drill down to the soldering point:
Sharpened drill bit with soldering.
It is advisable to sharpen the front surface. If the soldering has already been ground down to the very drill, then it is simply impossible to do without sharpening, since the soft metal extends to the cutting edge from the front surface. The front surface is simultaneously ground down so that the thickness of the soldering center becomes smaller.
Solder point on the front surface.
When sharpening the drill, try to be precise and carefully ensure that its cutting sides are the same size. If this cannot be achieved, then the offset center of the spine will certainly result in the drill hole being enlarged and uneven.
Regardless of the device on which sharpening is performed, it is necessary to control the ratio of the front and rear angles of the cutting edge in the direction of rotation. Another rule that should be followed in order to properly sharpen a drill for concrete: the harder the material, the greater the sharpening angle.
For victory it is 170 degrees.
During the sharpening process, the drill must not be allowed to heat up, because Cracks may appear and the carbide plates may peel off. In order to prevent this, you should periodically cool the drill with liquid. You can use regular water for cooling.
We invite you to watch a selection of videos on sharpening drills with pobedite tips.
: Sharpening drill bits for hammer drills. Part 2
Source: https://qteck.ru/kak-pravilno-tochit-nozhi-topory-sverla-po-metallu-na-nazhdake.html