How to sharpen small drills. General recommendations for sharpening drills. Preparatory stage before sharpening

Surely you tried to sharpen the drill with your own hands. Did not work out. Well, let's look at this problem. First, some theory and terminology. Then we will get acquainted with the tools and technology. Including with a budget kit for sharpening drills. Let's start.

The geometry of this tool is very diverse. We will consider only forms that are typical in terms of sharpening.

Cylindrical spiral.

The most common drill. Usually has 2 chip removal grooves, but sometimes more.

Stepped.

It is convenient to use when holes are drilled in sheet metal and different diameters.

Crown for metal.

Used for drilling large holes in sheet metal.

2. Drill material.

Consider the materials in ascending order of wear resistance and price:

Ordinary drill made of cutting steel without additional processing. The cheapest. Regular steel color.
Treated with superheated steam. Has black color.
Vacation-treated has a slight golden hue.
With the application of titanium nitride have a bright golden color.
Doped with cobalt are characterized by the presence of a golden-red hue.

3. Elements of a drill for sharpening.

For a better understanding, we will consider the elements for sharpening using the example of a two-fluted cylindrical twist drill.

The cutting edges cut the metal out of the hole area.
back surfaces. They are the ones that are processed sharpening drills a, to give the cutting edge sharpness and the desired geometric shape.
The jumper will be the first indicator of the correct sharpening of the drill.
It is on these elements that attention should be focused when sharpening the drill.

4. Device for sharpening drills in a workshop.

Here we will consider a device for sharpening a drill with tools that are often used at home.

4.1. Grinding machine (Bulgarian).

To obtain an acceptable quality of sharpening, it is necessary to fix the power tool.
With an assistant, everything is solved quite simply. Have a helper place the machine on a hard, level, level surface with the disc down and the shield up. For example, on the table. The grinder should rest on the disc shield. And, holding the case, in the places indicated in the photo, it will securely fix it.

If you do not have an assistant and suitable holders, you can use a banal locksmith or carpentry vise. Fix the angle grinder so that the vise jaws do not block the ventilation holes. The abrasive disc can be oriented both vertically and horizontally.

You can use a regular disk (cutting), but it is better to put a special one - sharpening. It is much thicker than the cutting one.

4.2. Hand drill.

For fastening a drill, everything that you read about fastening an angle grinder in the previous paragraph is true.

IMPORTANT! Only a drill with a cam chuck is suitable for sharpening.

Not everyone knows, but there are grinder disc holders on sale that allow you to use “grinder” cutting and grinding discs with a drill. So it is possible to replace the functions of the grinder with a high-speed drill.

You can also use a sanding disc with sandpaper glued to it. The harder the base on which the paper is pasted, the better. Now you can find sandpaper that does not stick to the disc, but sits on Velcro. This one fits too. In this case, the quality of sharpening will be worse.

Instead of a drill, a grinder disc holder or a grinding disc is installed in the drill chuck.

4.3. Peeling and sharpening machine (grindstone, emery).

Not every home has a similar unit. But we will take a brief look anyway. How to understand technology correct sharpening drills and how to properly adapt a home tool for sharpening is easiest on it.

abrasive wheel from electrocorundum it is intended for processing of steel, including sharpening of a drill.

Horizontally, at the level of the axis of rotation of the abrasive wheel is handyman- steel bar. Serves as a support for fingers and tools when sharpening.

5. Technology for correct sharpening of a drill on a peeling and grinding machine.

5.1. Preparation for sharpening

Draw a line with a marker on the surface of the handpiece at an angle of 60 degrees relative to the working surface of the abrasive wheel (the end of the circle that looks at you).

This helps to correctly orient the drill when sharpening. The angle shown in the figure is approximately 120 degrees in most cases. In general, the harder the metal for drilling, the greater this angle should be.

IMPORTANT! Do not use gloves when sharpening. Be sure to protect your eyes with goggles or a transparent shield. Beware of hand slip and strong contact with the abrasive wheel.

5.2. Initial position of the drill.

Hands, fingers should not be strained.

5.3. Drill movement during sharpening.

After setting the drill to its original position, slowly feed it forward until it touches the circle. Immediately after touching, we move simultaneously in three directions: the tip is up, the shank is down, the drill is forward along the axis.

5.4.

We repeat points 5.2 and 5.3 2 more times.

5.5.

We rotate the drill around the longitudinal axis by 180 degrees and follow steps 5.2, 5.3, 5.4 for the second rear surface.

5.6. What should we get.

Place the drill vertically, tip up. In this position, the entire flank must be below the cutting edge. Moreover, the farther from the cutting edge along the rear surface, the lower. In sharpening technologies, this is what is called - understatement.

By grinding the back surface, we underestimate it. As a result, only the cutting edges and the bridge touch the surface of the metal that the drill cuts. Lack of understatement is the most common mistake novice sharpeners make.

6. The technology of sharpening a drill for metal using a grinder or a hand drill.

If you figured out how to sharpen a drill on a grinding machine, then it's time to find out that this is done in a similar way on a grinder (grinder). As a handpiece, we simply use the edge of the abrasive disc guard. The rotation of the shield is adjustable. Before sharpening, turn it so that it is convenient to rest your finger under the drill being sharpened. Try to perform the same movements, one hundred and on a grinding machine. The fact is that you can learn how to properly sharpen drill bits on a sharpening machine quite simply and quickly. That is why it is recommended to fix the grinder - you will get a decent result faster.

With a hand drill it is more difficult. She has nothing to use instead of a handyman. But you can adapt improvised items for this. Here you need two stable flat surfaces. A drill is fixed on one, the other is used as a handyman. The surfaces are placed on the same level so that a disc mounted in a drill chuck can be placed vertically between them. For example, it can be tables, workbenches, boxes.

In any case, the quality of sharpening on a drill will be worse than on other tools considered.

7. Quality control of sharpening.

During sharpening, you will have to constantly monitor the parameters of the drill elements. In most cases, this should be done after all back surfaces have been treated.

7.1. Visual control of the jumper.

The jumper should be located in the center of the end face of the drill tip. Besides. Its edge should pass between the deepest points of the chip grooves. In other words, it should be as short as possible.

7.2. Cutting edge length.

This is the distance from the jumper to the edge of the drill along the line of the cutting edge. You can measure with a caliper or a ruler. Obviously, all cutting edges must be the same. If this is not the case, then the back surface that is shorter should be undermined.

7.3. Understatement control.

What is an understatement, we considered in paragraph 5.6. You can quickly check for its presence by placing the drill vertically, tip down, resting the jumper on any flat surface. Look at the back surface from the side of the drill. If you do not visually see understatement (the edge of the back surface, turned towards you, does not smoothly rise up), the surface will have to be resharpened.

8. Sharpening a step drill.

If you have mastered the sharpening of the twist drill, then this will seem like a sandbox to you. The photo in point 1 shows a stepped drill with a straight flute for chip removal. Lightly run the disc or grinding wheel along the cutting edges of the steps from the side of the groove. Be careful not to disturb the angle between the groove and the back of the step.
Things are more complicated if the groove is spiral. Sharpening is also performed, but more skill and accuracy will be needed.

9. Crown sharpening.

Take a closer look at the tooth of a metal-cutting crown. You will easily find all the same cutting edges and back surfaces. There will be no only jumpers and grooves for chip removal. Now you are smart enough to remove the minimum layer of metal from the back surface and get a sharp cutting edge. The crown may have a central twist drill. How to sharpen it, you already know.

10. Typical mistakes when sharpening.

10.1. An attempt to fix not a tool, but a drill when sharpening with a drill or grinder.

A heavy tool, with a fast rotating heavy rotor, will never become stable even in the hands of a strong man.

10.2. Excessive pressure when sharpening.

It is better to repeat the cycle of operations 10 times with light pressure, controlling the result after each cycle, than to turn a third of the drill into metal dust in the same 10 times.

Sharpening a drill at home is easy if you know how. The main difficulty in this matter is to maintain the correct angles. After all, at home, as a rule, there are no special mandrels and conductors. There is only one grinder. At least we will proceed from such conditions.

From equipment we have only an electric grinder. But the fact that it exists does not mean that drills can be sharpened on it. It is necessary that the grinding wheel has the correct shape - that is, the shape of a cylinder with a smooth, not rounded edge. Convex edge with chipped ribs can give incorrect sharpening

If the disc is very worn, it is better to replace it with a new one or fix it with a special elbor "pencil", if it is on the farm. It is very good if the disk is balanced, does not give beats and vibrations (in fact, this is a mandatory norm). Only the peripheral surface of the disc is involved in the work, not its ends.

There is a temptation to take advantage of the flat side surface of the disc. But after several sharpenings, it will lose its shape and it will be much more difficult to fix the stone after that.

Sharpening a drill for concrete

The drill for a perforator as a cutting part has a hard alloy plate inserted into a slot at the working end and fixed with solder. A normally sharpened drill has clear cutting edges with a sharpening angle of about 90 0 and an angle between the edges at the top - 130–140 0 .

With standard sharpening, the front face of the cutting edge (directed in the direction of rotation) is inclined to the axis of the drill at an angle of 30 0, and the back - at an angle of 60 0 . With manual sharpening, without special devices, you can focus on the whole, unworn part of the edges and reproduce their angles of inclination.

Sharpening process

We start sharpening from the front edges. We expose the drill near the peripheral surface of the stone so that the cutting edge is parallel to the sharpener axis and directed upwards, and the edge is parallel to the surface, and on a short time lightly press the drill to the grindstone. A clearly distinguishable mark remains on the metal, which shows whether its position has been chosen correctly. The plane of the trial cut should coincide with the plane of the facet, and the spot of the cut should be located in the center of its unworn part, without significant displacement. Having found by experience the correct position, remember it and proceed to sharpening.

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

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

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

After that, in the same way, alternately, the rear edges of the edges are ground, followed by a symmetry check. The symmetry of the location of the edges is also checked when viewed from the end, along the axis of the drill. When properly sharpened, they are parallel, and between them there is a jumper about 0.2–3 mm long, depending on the diameter.

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

Add-ons

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

For working on soft materials without impact, such as brick or tiles, the cutting edges are reduced “to zero”, without a jumper, and the angle of their sharpening is reduced to 30–35 0 .

How to hold the drill while processing

Since, according to the conditions of the problem, we do not have devices for precise positioning of drills, all hope for own hands. There are several simple tricks how to achieve a "firm hand".

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

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

In the most extreme case, you can simply press your elbows to your sides, forming a triangle with your arms and torso. But in any case, you need to find an opportunity for the most rigid retention of the tool with minimal effort.

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

Sharpening a drill for metal

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

sharpening

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

The drill is located at an angle to the working surface of the grindstone: 60 0 horizontally (half the angle at the top) and about 10 0 vertically. The sharpened cutting edge is directed upwards and is located horizontally, parallel to the axis of the stone. The selection of the position can be done with the machine turned off, according to the shape of the gaps between the edge and the grindstone when viewed from above, and between the grindstone and the back surface when viewed from the side. For a more precise setting of the sharpening angle, a clearly visible line can be drawn on the handpiece at the desired angle.

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

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

Additional processing

With proper sharpening, the cutting edges do not converge at the top, a short bridge remains between them. To reduce the resistance to entry into the material, the jumper is ground with a grindstone angle or a diamond file. Grinding is performed on both sides, symmetrically, at an acute angle to the axis of the drill, and the edge of the groove formed in this case is located at an angle of 30 0 to the cutting edge. The purpose of this operation is to shorten the jumper, but not completely grind it off! Without it, the drill will not center on entry.

The stitching of the jumper is carried out on drills with a diameter of more than 3 mm. But in practice, for simple jobs without high loads, the jumper, as a rule, is not ground even with a diameter of 10 mm or more.

Sharpening check

After sharpening, you need to check the tool in operation and, if necessary, correct it. Sharpening errors are indicated by several signs.

• Poor centering at the entrance, beating is noticeable during operation - asymmetrical sharpening of edges or jumpers.
• During operation, a squeal of metal is heard, the drill is very hot, the chips look like small grains - a large angle of sharpening the edge, insufficient lowering of the back surface (blunt edges).
• Increased rotational force, chipping occurs quickly on the cutting edges - too small edge sharpening angle (excessively sharp edges).

Signs of correct sharpening:

• clear centering at the entrance, stable operation, no beats;
• entrance to material is light, the chips come out in the form of identical “spirals” from both grooves;
• the heating of the drill is small.

Drill sharpening for wood

There are several types of drill bits for drilling wood and wood-based materials. Here we consider the most universal and common - spiral.

Features of drilling wood

A twist drill for wood differs little in design from its counterpart for metal. Even the cutting part can be the same. But wood has a fibrous structure. When it is drilled, the cutters in different directions interact differently with the material. This can result in scratches and chips on the surface of the workpiece. To avoid this and get a neat, even hole, a special sharpening of the drill is used, with a centerpiece and undercutters.

The first to come into contact with the material is a trunnion - a narrow spike located along the axis of the drill. Going deeper, it centers the tool, keeps it from lateral displacements. Then cutters come into play - side cutters protruding above the cutting edges. They cut wood fibers along the contour of the hole and prevent the spread of flakes beyond it. The contoured, virtually isolated material is removed by the main blades.

Working part geometry

The angles of inclination of the faces of the trunnion to the axis of the drill are 10 0 , the slope of the inner edges of the cutters is 30 0 , the outer edges of the cutters coincide with the side surface of the drill. The angle of reduction of the rear surface of the cutting edges is 25 0 . The height of the centerpiece and undercutters above the cutting edges depends on the diameter of the drill, but undercutters are always lower.

For example, a drill with a diameter of 10 mm should have a center center with a height of 3.5–4.5 mm, and undercutters with 1 mm. The width of the base of the trunnion is about 1.5 mm. See tables 1 and 2 of Appendix 1 to GOST 22053-76 for recommended parameters for different diameters.

How to sharpen

To perform such a complex sharpening, a stone of a special shape is needed. If there is a “pencil” for editing abrasive discs, you can give a standard grinding disc a trapezoidal profile (grind one edge into a cone) and assign this stone to sharpen only wood drills.

You can also use the disc for the "grinder" by installing it on the grinder. An adapter can be ordered for different bore diameters. Another option is to use the "grinder". But it must be securely fastened.

Sharpening is a familiar job

The process of sharpening a drill on a tree, in principle, does not differ from sharpening other drills. The same techniques for choosing the right angles, fixing the tool and controlling symmetry are used. If you just need to sharpen a dull drill, then there should be no big difficulties with good equipment. If you need to make a drill for wood from a standard one, then you should first practice on old drills, which are not a pity to lime for training.

A hand or electric drill is an indispensable tool in the household. The equipment is used at different stages of construction and repair work in and apartment. The main part of any drill is its drill bit. If it is poorly sharpened, then the hole will turn out to be wrong in size and depth, and will have to be redone. How to understand that a bur needs to be sharpened? By a characteristic sound that resembles a lingering creak. Gimlets that make holes in metal and concrete often fail. Those that interact with the tree break extremely rarely. This is understandable, because wood is a rather soft material compared to iron or cement. How to sharpen a drill for iron? To answer this question, you need to have an idea about the types of gimlets and how they are processed.

The drill is the cutting part of the drill. She cuts through necessary material(wood, iron, concrete), rotating on its axis. Use the tool to create a new recess or expand, lengthen an existing one.

For each type of work - its own drill. The smaller the recess, the thinner and shorter the nozzle.

By type of equipment are classified as follows:

• spiral;
• flat (feather);
• ring;
• center;
• deep;
• unilateral.

Spiral is easy to distinguish from the rest. The "drawing" on the gimlet resembles a spiral. The diameter of the tool is from 1 millimeter to 8 centimeters, the length is from 16 millimeters to 27.5 centimeters.

A twist drill for metal is most often used at home. For proper sharpening, the diameter of the product is important - it ranges from 1 to 8 millimeters.

A flat drill can create a fairly deep hole. The tool looks like a spatula with a holder at the end. The holder is inserted into the head of the drill.

The ring looks like a hollow tube, along the edges of which cutting elements are located.

Centering is used when it is necessary to center parts in industry.

A deep drill is usually flat. You need to create a hole up to 27 centimeters deep.

Unilateral nozzles are a solid tube in the form of a needle.

All these tools become dull during operation. Storage of equipment plays an important role in this matter. If, after operation, the bur is wiped with a dry soft cloth, placed in a box or box where moisture, dust, dirt and direct sunlight will not penetrate, then the tool will last 2-3 months longer without treatment than its “neglected colleague”.

It is not necessary to lubricate the cutters with machine or any other oil. They will quickly become dull, they will fly out of the drill socket.

Do not lubricate metal drills with machine or other oil. They don't need it. So you just make it harder for yourself

Even if you store your equipment as properly as possible, sooner or later you will need information on how to sharpen a gimlet. Working with a dull bur is not recommended.

Of course, a dull cutter can be thrown away and a new one purchased.

The thinnest and shortest drill costs about 150 rubles. The price of products thicker, more authentic and stronger reaches a thousand rubles.

Are you ready for this kind of spending? If a drill for metal or concrete is used regularly, then the cutters will have to be changed monthly. With a wood drill - less often (once every 2-4 months). At the same time, sharpening gimlets with your own hands is a simple, cheap and affordable process for everyone.

How to sharpen a drill: safety precautions

Before you start sharpening a drill for iron, concrete or wood, you need to prepare for the process:

• wear goggles on your face. During the procedure, sparks may occur due to active friction. Also, metal crumbs can separate from the tool, which can leave a deep cut on the skin;

Before you start sharpening the drill for metal, put on goggles so that small particles of the product do not get into your eyes and skin

• protect your hands with gloves that welders or builders use. You can find these at any hardware store. They cost about 50 rubles for a pair;
• put on thick working clothes so as not to worry about the safety of things and your own skin in the process of processing boron for iron, wood, concrete;
• during the procedure, strangers should not be allowed near the grinding machine. If another person works nearby, he should take care of his own safety in the same way;
• place a basin or bucket next to cold water. There you will periodically lower the tool to prevent it from heating up excessively. Too high a temperature can destroy the gimlet material.

We use the machine

The easiest way to sharpen a bur is to use. There are professional and household models.

The first ones cost from 20 to 100 thousand rubles, the second ones are much cheaper - from 1.5 to 5 thousand rubles. Machine tools from manufacturing companies are especially popular: DIOLD, Sturm, Energomash, Enkor, Oregon.

The easiest way is to sharpen a drill for metal using a special machine. For work at home, choose household appliances

When choosing a machine, be guided by the following parameters in order to properly sharpen drills for metal and other materials:

• works from a network of 220 volts;
• has a transparent screen for protection;
• designed for different types of equipment;
• has an emergency shutdown device;
• protected from power surges (there is a residual current device in the design);
• grinding element rotation frequency - at least 1000 rpm

How to sharpen a perk without a machine: we use improvised means

No funds and desire to purchase a special machine to sharpen perk on steel? Use improvised means:

• a rock;
• grinder;
• thick sandpaper.

With their help, you can perform the procedure in various ways:

• simple. The cutter is placed on sharpening strictly parallel, not at an angle. In the process, you can not move the sharpening. Used for tools with a diameter of 1-3 mm. Using this method is fraught with the fact that the product soon begins to crumble;
• conical. Applied to equipment with a diameter of more than 3 millimeters. The tool is pressed against the sharpening at an angle. The product is swayed from side to side to ensure uniform treatment of the entire surface.

Determine the required sharpening angle using the table:

In order to sharpen a perk for metal accurately, use a template. You can do it yourself:

• take a sheet of aluminum or steel no more than 2 millimeters thick;
• prepare a new gimlet;
• make a cone out of steel or alumel sheet. Its dimensions and angle must correspond to the new product;
• using the template, you can easily understand whether a used product needs to be processed.

How to sharpen gimlets on steel: we use a grinder

There is no machine in the house, but there is a grinder? It will perfectly perform the correct sharpening of the drill. There are 2 ways to work with such a tool:

• place the cutter in a vise, securely fasten in one place. Put on the grinder a disc designed for metal processing. Walk the disc along the pine forest in parallel on each side;
• secure the grinder itself in a vice. The main thing is that she tightly "sit" in one place. Put on a special disk, turn on the tool. Bring the gimlet at the desired angle to the rotating disc. Hold the cutter firmly so that it does not fly away.

Do not forget to observe the angle of sharpening the drill. It is critical, otherwise the cutter cannot be used where it is needed. Such processing of a drill for metal with your own hands should be carried out with a properly functioning vise that can hold the grinder or bur in one place while you sharpen the drill.

Do-it-yourself metal drill processing

Using ordinary sandpaper, you can sharpen drills correctly. This is done with strict observance of the angles of sharpening the drill.

If you just take the sandpaper in your hands and drive it back and forth along the gimlet, then the sharpening angles may be observed, but the process itself will stretch for several hours (whereas auto-sharpening takes 10-20 minutes).

To quickly and easily sharpen a metal drill with sandpaper, attach the latter to a moving element. Manual sharpening will take several hours

To sharpen a drill on concrete or other material with sandpaper, the paper must be attached to any rotating element that makes at least 1000 revolutions per minute.

Any tool with a rotating part can be used. To the moving element, you can attach sandpaper or reduced, depending on the wishes and capabilities of the owner. So you can simply sharpen the drill at home without buying expensive equipment.

For the correct sharpening of a drill for metal, a grinding stone is sometimes used. They also process knives, screwdrivers. It costs about 100 rubles. Here you can’t do without a sharpening angle for a drill for metal, see the table.

How to sharpen a victorious drill?

The winning product differs from the rest in its special strength. Pobedit is an alloy of carbide, tungsten and cobalt. Able to destroy stones, concrete, brickwork.

If the product began to “squeal” during operation, it must be urgently sharpened. How to sharpen a drill bit at home? Only with the use of a grinder. It is necessary to put a diamond disk on it.

Only such a one is able to correctly sharpen a victorious drill. Hold the tool at an angle of 170 degrees.

The Pobedit drill for metal is considered the strongest and most wear-resistant. It can only be sharpened at an angle of 170 degrees, otherwise sharpening will not be done properly.

AT this case the disk should rotate slowly - about 700-800 rpm. Only then will the win become sharp again.

Finally

The most important thing in properly sharpening a drill is your own safety. Gimlets are sold in stores, but health, unfortunately, is not. Be sure to wear special goggles, gloves, robes before sharpening a bur for metal with a grinder, stone or sandpaper.

When using the machine, also take care of your safety, despite the fact that the machine is equipped with a protective screen.

If the product is more than 4 centimeters in diameter, it is impossible to sharpen it with your own hands. For this, only special equipment is used.

For proper sharpening of a gimlet for metal, use a template made of steel or aluminum sheet. Make a cone and measure the new piece, then apply the template on the used nozzle.

A victorious product will sharpen only a diamond. Other materials will be powerless. The diamond disk can be planted on the grinder.

A visual demonstration of how to sharpen a bur at home is presented in the following video:

Over time, the drill "bites" into the metal worse. For this reason, it is thrown into the trash and replaced with a new one. However, the problem can be approached in a businesslike way: with the help of special tools, sharpen a dull drill and return it to working condition. Moreover, you can again make the cutting tool sharp at home, without resorting to "high technology".

Types of sharpening

You can sharpen a drill that has become poorly immersed in metal in different ways. This is influenced by the scope of the cutting tool and its diameter. Based on these criteria, sharpening can be single-plane, conical and finishing. Most men who use a metal drill are more accustomed to performing a single-plane procedure, which is considered the most simple. But it, like other types of sharpening, is not suitable for every cutting tool.

One-plane sharpening should be resorted to if the diameter of a dull drill is no more than 3 mm. True, when making a cutting tool sharp in this way, one must be extremely careful, otherwise it is threatened with surface destruction. In order for single-plane sharpening to be successful, you need to attach the drill to the abrasive wheel and move it in the same direction as its surface.

It is necessary to use the conical procedure when it is necessary to sharpen a large product intended for cutting metal sheets and parts. Such sharpening assumes that the drill is fixed with two hands and processed sequentially. Then, with the cutting tool, the so-called finishing is carried out. It must be performed after both single-plane and conical sharpening. Finishing is a procedure that grinds the cutting edge of the drill so that even small notches remain..

Angles at which the procedure is performed

A drill that has become dull after intensive and long-term operation is usually sharpened at an angle of 120 0. This is a universal sharpening parameter for any material, but it is only suitable for products with a diameter of less than 1.2 cm. And if this size is from 12 to 80 mm, then the cutting tool is processed at a different angle. The main thing is to choose it based on the material.

Sharpening a drill at an angle chosen at random will make it sharp, but will certainly ruin it. It will not drill holes well and heat up quickly, or worse, it will break during use.

How to sharpen a dull drill with simple tools

You can return the cutting tool to its properties using an abrasive bar. They will have to grind the drill manually, carefully removing excess metal. But this business will take so much time that next time you will definitely want to make the product sharp with any device, but not with an abrasive bar.

But it won’t hurt anyone to understand what sharpening with an abrasive bar is. To learn the nuances of processing a cutting tool with such a device, you can watch the following video:

Electric grinder

A device that runs on electricity and can sharpen a drill is not for everyone. But he has a huge plus: at home, it is easiest to adapt to handle a blunt product with an electric grinder. Sharpening with this tool is supposed to start with an edge located in the same direction as the axis of the abrasive wheel. How long to remove excess metal from the drill, it is necessary to determine "by eye". The work should be completed at the moment when the shadow from the edge on the groove disappears.

In sharpening the drill with an electric sharpener, a certain sequence must be observed. The first step is to process the back surface of the edge, and only after that proceed to remove the unnecessary layer from the second edge of the blunt cutting tool. When turning a drill for metal with a sharpener, you should follow the rules:

• pay attention to the angle of sharpening the product;
• make sure that the drill is fixed on the axis of rotation;
• observe the process so that the edges are the same length;
• excess metal should be removed gradually, slowly expanding the gap between the sharpener washer and the workpiece;
• completing sharpening, it is necessary to give the edges of the drill a cone shape.

Sharpening a drill with an electric tool is simple, but this will require straining your eyesight without losing sight of any trifle. In order to learn how to properly focus on the processing process, you need to practice, possibly rendering several metal drilling products unusable.

Video about working with an electric grinder

Bulgarian processing

Sharpening angle drill grinder provides for the following: the cutting tool is fixed in a vice, the mounting angle is selected, then a disk is mounted on the grinder, which rotates and is brought to the edges of the blunt product. This method of giving the drill sharpness lost over the years of operation has a large number of disadvantages:

• the grinder needs to be placed on a flat surface with the disc down and kept in its place, for which it is necessary to enlist someone's help or use a vice that performs the work of a carpenter;
• the grinder can ruin the drill if it is not securely fixed;
• when sharpening a cutting tool with a grinder, there is a high risk of injury, as the drill may accidentally jump off a rotating disk;
• it is advisable to sharpen with a grinder only a product that has a small diameter;
• it is impossible to grind with a grinder, giving the cutting tool evenness and smoothness.

The role of the stand for the cutting tool during its sharpening with a grinder should be performed by the edge of the shield covering the abrasive disc. The shutter rotation can be changed. When starting to process the drill, it must be positioned so that it is convenient to put a finger on it for support.

Video on the use of a grinder for sharpening metal drills

Using the drill bit

The drill is attached in the same way as the grinder, therefore it is characterized by similar disadvantages. In addition, one more thing can be added to them: a drill for metal can only be sharpened with an electric tool that has a cam chuck, into which instead of a drill you need to insert a disc holder from a grinder.

The drill, which is planned to be used for sharpening the drill for metal, is recommended to be equipped with a grinding disc with a piece of sandpaper glued to it. It is desirable that the base on which the rough material is glued is very hard.

If you plan to sharpen a cutting tool with a hand drill, then you need to mentally prepare for the difficulties. Still, she has nothing that can be made a stand for a drill. Therefore, it is necessary to use some kind of improvised object as it.

In general, when starting to grind a product with a drill, you need to find two even surfaces. One of them will become a platform for fixing the device itself, and the other - a stand for the drill. Both surfaces, for example, a table and a box, must be placed so that they are on the same line. Between them it is supposed to install a disk inserted into the chuck of a hand drill in a vertical position.

Video about processing a cutting tool with a drill

Features of sharpening various types of drills

A drill for metal can be victorious, spiral and stepped. There are certain requirements for sharpening each. But before you figure out how to return the properties lost over time to the drill, you should inspect it and test it in operation. This will allow you to understand whether the product really needs to be polished. Signs of a dull cutting tool are its strong heating, loud sounds heard during its use, and poor-quality drilling. True, resorting to sharpening is not always wise. A drill with a cutting surface length of more than 1 cm should be discarded.

How to grind a victorious drill?

In order for the victorious product to create holes in the metal to bite into the material again, it is necessary to arm yourself not only with a sharpening tool, but also with coolant. It will not work with a simple emery stone to sharpen a drill of this type; you will have to arm yourself with an electric sharpener.

In order for the cutting tool to drill into metal as efficiently as before, on the device used to sharpen it, the number of revolutions per second should be reduced. The fact is that the higher the strength of the material, the lower should be the speed of its processing.

The Pobedite drill is supposed to be ground with short touches to the sharpener. The process of sharpening this product requires increased attention, because the edges of the drill bit sharpen rather quickly. Each cutting side of the tool must be sharpened to match the other side in size. If this rule is violated, then the center of the axis of rotation will shift, and the drill will make holes in the metal that are too large and curved along the edges.

When grinding a cutting tool, it is important to keep the ratio of the back and front angles of the cutting edge under control. Care must also be taken to ensure that the drill does not become hot, as this can lead to cracks and chips. If suddenly the product processed by a grinder or other device heats up, then it must be lowered into a special liquid or plain water. But, seeing that the tip is reddened and glowing, you should not immediately cool it in order to prevent damage. Before immersion in water, the drill must cool down under the influence of air.

How to sharpen a spiral product?

To restore the sharpness of the drill in the form of a spiral, you need to grind its back edges. During this process, care should be taken to ensure that one drill bit is sharpened in the same way as the other. It is very difficult to do this without a special unit, especially for those who do not have experience in sharpening metal drills.

When sharpening a twist drill with one's own hand, it is unlikely that it will be possible to give an ideally correct shape to the back edges and a given back angle. Therefore, it is more reasonable to grind such a product on a special machine or fixture. If only the household had an ordinary chisel, and the man who needs to process a dull twist drill had experience in sharpening cutting tools.

How to properly process a step drill?

The cutting tool for metal, which has the form of steps, is several times more difficult to sharpen than a twist drill. A product with a straight flute for chip removal should return the lost sharpness according to a certain pattern. Along the cutting edges of the steps from the side of the gutter, it is supposed to be carried out with a disk, making light touches.

When processing a step drill, the angle formed between the surface behind the step and the groove must not be displaced. There are even more sharpening nuances in a product whose chute is spiral. The technology of its processing is no different, but it requires extreme accuracy and great experience in grinding drills.

Gallery of drills of various types

A cutting element of this shape can also become dull The product is already mounted on the tool and is ready to work Drills can break, so it is advisable to have a whole set
Such a drill bites into the material quickly
In case of twist drill breakage, have spare cutting parts
The tips of the step drill can have different diameters. The cutting element is shaped like a cone. The drill of this type is smoothly immersed in the metal.

Evaluation of the quality of grinding

Having sharpened the drill for metal, it is imperative to check whether everything is done correctly. Quality control of cutting tool processing is easy to check. It is only necessary to inspect the jumper located in the center of the end of the tip of the product, evaluate the length of the cutting edges and understatement.

If the sharpening was done without errors and did not spoil the drill, then the jumper will be located in the center of the end of the tip. With proper rehabilitation of a blunt tool, its edge will be between the deepest points of the troughs through which metal chips are removed. This means that the edges of the sharpened drill should be short.

Next, you need to check the length of the cutting edges - the gap between the jumper and the edge of the drill along the line of the edge that cuts the metal. This parameter can be measured with a regular ruler or compass. Naturally, no edge should be different from the other. Otherwise, you will have to take the sharpening device again and process the surface that turned out to be short.

You can understand if the edges of the drill have an underestimation, if you put it vertically so that the tip points to the floor, and rest the jumper against some flat surface. Then you need to glance at the back surface, while being on the side of the sharpened product. If the visible edge does not rise gradually upwards, then it is necessary to work again on the cutting zone of the drill.

Sharpening drills, without a doubt, requires skill. You can get your hands on this one. It is only necessary to study all the subtleties of the process and see firsthand how the grinding of blunt cutting tools is performed.