I confess that sharpening a tool has always caused me a quiet horror. You need to think not only about the rotating sharpening stone, which is a source of potential danger, but also to keep the sharpening angle ... I think this article will be useful for novice brainworms, and for experienced comrades I have a earnest request to supplement the information below or tell about my method of keeping the sharpening angle ...

Materials (edit)

• Wooden block;
• Screw.

Instruments

• Protractor;
• Malka (device) - carpentry and metalwork tools for marking and measuring angles, drawing parallel lines. Consists of two parts, fastened together with a clamping screw. The thicker part (block - base) is pressed against the workpiece, marking is made along the thin part (ruler). Sometimes there is a scale for measuring angles between the two parts of the bevel. Large beads can be used for construction work;
• Drill with a drill for wood;
• Screwdriver.

Step 1: 59 degrees

Draw two straight lines on the paper at a 59 degree angle. The goal is to sharpen the drill at this angle.

Step 2: mark the corner on the bar

Using the bevel, transfer the 59 degree angle onto the block of wood. I used hardwood as a blank. Bar thickness 15 mm. A screw with a fine thread for a slotted screwdriver will protrude as a guide, so the through hole should be slightly smaller in diameter than the diameter of the screw so that it is tightly screwed into the block. Drilling in wood is easier when you start drilling at an angle. By eye we determine the place where it is most convenient to place the screw.

Step 3: screw in the screw and check the angle

We screw the screw into the block. The maximum diameter of the drill that will be sharpened should be determined in advance. For this crafts the drill diameter will be greater than 15 mm. Therefore, choose a screw that is long enough to pass through the block and protrude about half the largest diameter of the drill to be sharpened.

If the angle at which the screw comes out of the block does not match the reference line, drill another hole and try again.

Step 4: Using the Reference

Turn the screw a few turns so that the end of the thread is over the center of the drill.

Once you have sharpened one side (using the screw threads as marks), turn the drill halfway and look at the marks on the screw. Repeat the operation for the other side of the drill.

Step 5: sharpen

As for sharpening drills, there is a detailed article on the site. In addition to the material presented in it, I propose to watch the video of the English-speaking Kulibin.

Thank you for the attention)

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

Features of the drill

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

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

The main elements of the cutting part of the drill

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

1. Main cutting edge.

2. Auxiliary helical cutting edge (tape).

3. Jumper.

4. Front surface.

5. Back surface.

What do you need for sharpening?

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

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

2. Tank for coolant.

3. Cooler (water or engine oil).

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

Controlled parameters

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

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

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

3. Apex angle located between the two main cutting edges when viewed from the side of the drill.

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

Sharpening process

Now let's talk about how to sharpen a drill bit for metal on regular emery. The main sharpening of this axial tool is carried out on the flank surface. To do this, turn on the emery, firmly hold the drill in your hand so that the main cutting edge is directed towards the rotation of the sharpener. Now we bring the edge to the sharpener, after which we turn the drill by the shank so that the cutting edge is parallel to the surface of the circle. We do the same with the second cutting edge. The result is the so-called simple sharpening of the drill, which is optimal for most metal processing modes.

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

Sharpening with a fixture or machine

The method described above can be called artisanal, since it is simply impossible to achieve accurate control of the drill parameters directly during sharpening. At best, you check the corners after you finish sharpening, and at worst, you just check how much better the drill is performing. How to sharpen the drill correctly?

Of course, for this it is better to use more advanced options, which will allow you to pre-tune to certain angles. In this case, you will need a tool or machine for sharpening drills.

If the scale of work in your workshop is large enough, and tool regrinding is required constantly, then the purchase of a machine will be optimal. It will greatly simplify the process, especially if you need to re-grind carbide drills for metal. The main advantage of its use is the exact adherence to predefined parameters. With a large volume of work, it is unacceptable to use an incorrectly sharpened tool, as this will lead to a decrease in productivity. Modern sharpening machines allow you to obtain various types of drill sharpening:

1. X-type. Mostly used for blind hole drilling. Designed to reduce the axial cutting force.

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

3. S-type. It uses the sharpening described above, which also allows for longer drill life in a variety of materials (from cast iron to stainless steel).

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

Fixture design

As it has already become clear, manual sharpening of a drill is a job of a professional who not only knows the correct angles, but also feels the cutting process. Unfortunately, such a flair comes only after many years of practice with a drilling machine or drill. You should not experiment, as you can make it yourself or purchase a sharpening device. In both cases, it will include the same structural elements and work according to the same principle.

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

As a column, you can use any bearing assembly with a shaft, for example, from an old drill. On the shaft rings, a drill bed is adapted (you can use an adapter sleeve), to which it is pressed with screws. After fixing the drill, the sharpener drive is turned on, the column is brought to the grinding surface and rotated to give the back surface of the drill the correct shape. It is important that the initial setting of the fixture maintains a 118 degree drill tip angle.

Sharpening with nozzles

Another simple and convenient method involves the use of a device such as a drill sharpener. Its main advantage is its versatility and ease of use. The device has a cylindrical shape. On one side there is a connecting unit, by means of which the nozzle is installed on the drill spindle. On the other side there are holes for installing drills of a certain diameter. For sharpening, the drill is inserted into the hole, after which the sharpening mechanism is driven by the drill motor.

Security measures

Drill sharpening is associated with the formation of small particles that come off the sharpener during wear. They heat up and scatter in different directions in the form of fiery sparks, so for safety it is worth using protective goggles and gloves.

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

If you are constantly dealing with sharpening hard workpieces, then the surface of the drill will very quickly become unusable. It will become dull, it will be very hot and, as a result, will lose its former strength. All this is a consequence of "letting go" of the metal. That is why such a tool needs periodic sharpening with special devices.

How to make homemade tools for sharpening drills, what templates exist for this and what needs to be prepared for work, you will learn from our article.

Drill sharpening features

Drills are inexpensive tools, especially when it comes to those that are widely used for domestic needs. However, if there is a possibility, then after blunting it is better to sharpen the tools than to buy new ones.

There are factory-made sharpening devices, but when you buy them, you will spend a lot, and this will not make up for the savings if you refuse to purchase new tools. That is why many craftsmen collect machine tools for DIY sharpening.

It is worth noting that bluntness concerns drills for metal, since wood tools are practically not susceptible to this, with the exception of cases of use at high speeds with a resinous workpiece. Also cannot be sharpened victorious tips for stone or concrete.

But many people sharpen metal drills with all the additional devices with their own hands, but the accuracy of such work is far from always ideal, so it is advisable to use at least a minimum of mechanics.

How to make a tool for sharpening drills with your own hands: a training video

To make such a device yourself, you need a control tool (template). Whichever way the drill is sharpened, the accuracy is checked with a special template.

Simple drills for ferrous metal have an edge angle of 115 to 120 degrees. If the metal is different, then the sharpening angles will also differ:

You can prepare immediately multiple templates depending on the listed values ​​and, in accordance with them, do the sharpening with your own hands. The same drill can be used for different types of workpieces, you just need to change the angles of the top of the workplace.

A simple but very convenient dragging device is bushings of different sizes that are attached to the base. You can make them yourself, based on special drawings. Remember that the tool in the sleeve should not wobble and the drilling quality may deteriorate even if the error is only one degree.

You can make a large clip based on aluminum or copper tubes, depending on the typical parameters of the drills, or you can take a block of soft material and make many holes in it. It is very important to put a handy tool in the sharpener, thanks to which it will be possible to move the sharpening device at the desired angle and hold the stop.

The listed devices for sharpening have been manufactured for many decades in a row and are still in demand. To assemble a sharpening machine with your own hands, you can take an oak block instead of a corner.

The simplest sharpening machine can be assembled by simply placing a workbench or table in front of the side of the emery. Even such a simple device ensures high quality and accuracy of work.

Features of sharpening on a simple device

On the Internet you can find finished drawings devices for sharpening drills, or sketch them yourself, but for this you need to understand the principle of working with a drill.

During work Absolutely forbidden allow the drill to move around its axis. If it rotates at least a millimeter, it will be damaged, and you will have to grind a short distance to re-process.

After finishing work, the drill should cool off, also measure with templates. Edges should be perfectly symmetrical down to tenths of a millimeter. This is especially important if the drill has a minimum diameter.

Sharpening can be accompanied by the following errors:

How from improvised means with your own hands assemble a twist drill grinder for metal?

For the basis of the device, you can take any grinding machine that is able to work properly, there is no axle runout, and it keeps the revolutions under load.

The task looks like this:

• the handcuff is obliged to stand strictly horizontally on one axis with the rotation of the emery;
• the structure must be safe, reliable and durable;
• it should be possible to sharpen both manually and semiautomatic;
• the shape of the hand-hand should facilitate the free lowering of the drill shank to the desired angle.

No specific details are required for the manufacture of this device; every home craftsman has almost everything you need. Workpieces are processed grinder, welding or sharpener.

For the semi-automatic mode, an oscillating stop is assumed, so a loop connection must be made. Match exactly for lack of backlash bolt, bracket and tube holes.

The site must move on the vertical axis so that you can change the angle of sharpening of the drill. This axis can be fixed, and the handlebar must swing, while resting on the horizontal axis, which, when sharpened, provides the desired articulation.

Base plate is made of metal 4 mm in thickness, and the main parts of the structure should have a thickness of 3 mm, respectively. This ensures its high strength. The handrail is rigidly connected to the emery body. It is impossible to attach it to the protective casing, therefore, screw the bracket using the metal "cheek".

Then screw the guide plate itself for drills with a thickness of 5 mm to the base plate. In it, to fix the drill during processing, it is sawn triangular groove.

The design has a rotation angle of 90 degrees, which makes it possible to ensure different methods... Starting from the Leontief method and ending with a clamp at a certain angle and the creation of an acute angle of the edge thanks to the curvature of the emery.

The drill during processing will not only stand firmly in the groove, it can also be fed along the groove to the abrasive, and the sharpening angle will not deviate at the same time. Due to the partial excess of the plane of the base plate over the axis of movement of the disk, it is possible to achieve the desired shape of the sharpening of the nape of the edge.

Before performing work, the drill should press against the plate and set the cutting edge parallel to it. This is the end of the adjustment and you can bring the tool to the emery. Sharpening should be done slowly and carefully, carefully following the angle.

Thanks to such a homemade tool, high precision sharpening and almost no template needed. True, it will take time to install the machine and adjust the angle, but then you sharpen drills quickly in the right amount.

But if you need to sharpen a drill equipped with a carbide tip, you can attach a swinging plate to a fixed angle. For this, several washers are placed under the axle nut.

Using an emery wheel in a homemade sharpening tool

For general-purpose grinding work, white corundum-based circles are mainly used. They are used for sharpening shovels, axes, knives and metal blanks.

For the purpose of machining carbide drills or high-speed metals, abrasive green silicon carbide wheels marked 64C should be taken. But for household needs, a circle grain size of 25N is enough.

Sharpening drills requires a finer fraction in the area from 8H to 16H... Remember that silicon carbide emery stones get very hot during operation, so the drill cannot be kept in contact with such an abrasive for a long time. Let the metal cool down after 2-3 sets and chill it in soda water.

Edge quality depends on direction rotation of the abrasive... Its working surface must run into the cut (go from top to bottom).

Peripheral emery surface during processing must be flat. It can be adjusted with an elbor-based attachment. If the disc has a small diameter, pliers can be used to hold the CBN cutter.

So, we looked at how at home you can assemble and use devices of varying complexity for the purpose of sharpening drills and more. You can choose the appropriate option depending on your household needs.

Drills are different, but in practice we often use those that are designed for working with metals. Despite the fact that such a tool is made from special grades of steel and undergoes special hardening, it dulls over time. A zealous owner will never throw away even the cheapest twist drill, since it is easy to restore its performance on his own, especially since such a person always has an "emery" (the simplest grinder) in a private house or garage. How to sharpen a drill for metal correctly will be discussed in this article.

Sharpening is different, and this largely depends on both the diameter of the drill and the specifics of its application. For example, on the type of metal with which it is supposed to work ("hard" or "soft").

What to look for

• In the process of work, the edge is located strictly parallel to the working surface of the stone (axis of the sharpener).
• The main thing is the gradualness of sharpening. It is undesirable to "press down" the drill to the circle too much.
• The length of all edges must be the same.
• The indicator of the completion of the work is the absence of reflective glare on the treated surface.

You need to know that there is no universal meaning. For each type of material to be processed, its own sharpening angle is selected. The approximate values ​​are shown in the table.

Sharpening types

One-plane

It is used, as a rule, for drills no more than 3 mm. The disadvantage is that in the process of work, partial "chipping" of the edge can occur, so this technique requires special care. The point is that the tool is applied to the circle and moves parallel to its working surface.

Conical

Suitable for drills over 3 mm. The tool is held with two hands, while sequential sharpening of the feathers is performed (light pressure against the stone with a slight "wiggle").

Debugging

It is advisable to do it after the drill has been sharpened. The task is to remove the smallest notches, grind the cutting edges. For this, the appropriate stone is used ("soft").

For many people, self-sharpening of a tool on emery / emery is fraught with certain difficulties or becomes impossible. The reason is poor eyesight.

Judging by the messages on various forums, neither good illumination nor glasses with high diopters help. Those for whom this is really a problem can be advised to purchase a special machine. For example, made in China. It is inexpensive - about 1,500 rubles.

And despite the fact that our attitude is, to put it mildly, “wary,” to products from this country, those who have already worked with them speak very well of such products (for example, “Caliber-ezs 200s”). The range of machines is quite large, so there is always a choice ("Mikra-10" and a number of others).

To ensure greater accuracy of sharpening and to facilitate this process, a special device can be made. Its meaning is clear from the figure.

If there is no emery at hand (and strict requirements for the angle), then you can use a "grinder" to sharpen the drill.

A video from the respected master Viktor Leontyev clearly demonstrates the whole process, so if some of the nuances of sharpening remain unclear, you should watch it:

Precise and centered drills are essential for smooth operation. We propose to consider where you can buy a machine for sharpening drills, how a home-made unit is made, and also how household models differ from industrial ones and what their price is.

Drill types and basic concepts

There are several types of drills, because they are subdivided according to the principle of operation and the relation of working surfaces, they also need to be sharpened in different ways, let's get acquainted with the main ones:

• spiral. They are used in almost all types of industry, household work, repairs, etc.;
• flat - these are more narrow-profile tools, they are mainly used when drilling holes of large diameters, they got their name due to the flat working edge, which is very similar in shape to a reamer.

Consider the fundamental provisions of sharpening twist drills and countersinks:

During the movement of the cutting surface in the material, chips are formed inside the processed raw material, especially this process manifests itself in the front surface. It is the large accumulation of chips that plays the main role in the deformation of the plastic parts of the drill: during operation, it heats up, and under the influence of the sharp ends of the chips, its working edge changes. Of course, there is a huge difference in the speed of this process, the most dangerous and tough one is copper and steel.

Photo - Cleaning the drill from shavings

Drilling is carried out according to the following scheme: during operation, a conical surface is described, this shape is also acquired by the working surface of the drill, respectively, the cutting edge becomes somewhat dull and changes its center. All corners of the working surface must be located above the surface of the end face, this is the only way to ensure a normal and standard clearance angle.

The easiest and most effective way to sharpen a drill at home is to use an electric sharpener. You can work with a conventional sharpening bar made from a mixture of abrasive materials, but this process will take a lot of time and effort, unlike operating a device with an electric motor. The universal hand-held grinder has a motor with a speed of 1500-2000 min -1. Optimum power: up to 300 watts. Such models are available from the firms Doctor (Doctor), Vollmer, Sturm, Proxxon, Drill and Weinig.

Photo - Sharpened drills

Orientation is carried out along the cutting edges; it is necessary to act strictly in the direction of the spiral grooves, because they do not change their shape even when exposed to large amounts of shavings. We fix the drill so that the edge to be sharpened is strictly parallel to the axis of the grinding tool. The most important question: when is the working part sharpened? As soon as you see a reflection of light from the work surface, it means that the edge is sharpened. We also sharpen the second side using the same system.

Photo - Drill sharpening

In this case, it is very important not to center the drill earlier, in which case you will lose its balance, and during operation the tool will deviate by several degrees from the standard-set parameters. The angle between the lumps is the most important sharpening parameter.

Photo - Cutting angle

Standard sizes look like this:

Alloy steel, structural steel, tool steel - over 90 degrees;

Soft metals (copper, aluminum, aluminum alloys) - 90-100 degrees;

Wood, plastic, rubber - 90-100;

Bronze, brass - 110-120.

In order to achieve high processing accuracy with your own hands, you need to pay special attention to the standard and deformed parameters. To control the sharpening process, you can order a special drill template with the required diameter and angle. The photo shows a diagram of the processing of a drill with such a device.

Photo - Sharpening template

If there is no money or time to purchase a template, use the "old-fashioned" method: we act according to the rule of left-hand mechanics. We bend the arm and replace it in this way over the drill so that the cutting surface is closed on several sides, a kind of corridor should turn out. We place a lamp opposite the end surface, and check the evenness and accuracy of sharpening (this will be clearly visible from a distance of 20 cm from the drill, if you look with one eye).

Photo - Left hand rule
Photo - Flare Check

When using a homemade electric machine, it is very important to control the process of sharpening drills. For a complete violation of accuracy, it is enough to be in error by 1 mm. The small diameter automatic core drill sharpener can also be used for discs, knives, scissors, chains, etc.

Video: Sharpening machine Energomash TS 6010S

Professional ways

The methods listed above are suitable for home narrow-profile use, but if you need to sharpen the drills serially, then you will not have enough time or energy to manually center, check or sharpen. Let's take a look at how a professional drill machine is used.

The grinding wheel must be made of fine abrasive material. The sharpening point must be illuminated at the correct angle in relation to the drill. The employee must wear protective goggles and gloves.

Step-by-step instruction:

Before choosing a machine for sharpening drills, you need to read reviews about it, carefully study the passport and capabilities. One mechanics forum even advised that you always carry a drill with you so that you can check the effectiveness on the spot.

Price overview

To buy an inexpensive drill sharpening machine in Ukraine, Russia or Belarus is real, the main thing is to choose the right model (for metal, wood or plastic), caliber (dd750хibm, drillgrind, edbs2001 - universal), and power. We propose to consider the average prices for such devices:

Now, desktop and universal machines of such brands as DrillGrind, Shturm (produced by Energomash), BSG, BSM, ESM, MICRA, V391, Diold, EZS, NKCH are very popular. They can be found in a professional store, on the Internet, on forums under the heading "Selling electrical appliances". The main thing is to make sure that the documentation corresponds to the data declared by the seller.