Any cutting attachments for a drill become dull during operation, which, in fact, does not require proof. However, do not rush to throw them away, since you can return the nozzle to its original functionality by sharpening it. Next we will describe in detail how to do this.
While wood drills can be used for a long time and still remain sharp, metal tools become unusable very quickly. Certainly, experienced master identifies a dull drill by eye or by its first contact with the metal surface. If you are a beginner, you can determine the need for sharpening of a tool by the following criteria:
Keep in mind that if you use a blunt tip you are putting yourself in danger and it may break. In this case, its flying parts can cause serious injury. In addition, the drill can “bite”. In such a situation, if the drill is powerful or you are working on a machine, the part is torn out of your hands, which often also ends in injury. Therefore, under no circumstances should you delay sharpening or replacing the tip.
So that you can properly sharpen the tip, first of all, let's look at its main elements, which include:
During operation of the nozzle, the cutting edge, bridge and rear surfaces suffer the most. Therefore, the restoration of the tool occurs by sharpening the rear surfaces to which the cutting edge and the bridge are adjacent. However, not everything is so simple: in order for the edge to become sharp again and a clear bridge to form, the sharpening angles must correspond to the values from the table:
Maintaining these values will allow the cutting edge to always be the first to contact the surface of the workpiece, which will ensure maximum tool efficiency. The length of the cutting edge depends on the apex angle. Compliance with this will allow the chips to fit well into the groove and come out. If you make the angle more acute, the width of the cut strip will increase, as a result of which the chips will clog the groove and will no longer be removed from the hole with all the ensuing consequences. Too obtuse angle will reduce drill efficiency.
At home it will not be difficult to use a regular sharpening machine. The only thing is that it is desirable that the machine be equipped with a tool rest, i.e. a small platform located in front of the working surface of the sharpening disc. The distance between the tool rest and the end of the circle should be no more than one millimeter.
The optimal rotation speed of the grinding wheel is one and a half thousand revolutions per minute.
If the nozzle is very dull, i.e. the cutting edges with the rear surfaces have become asymmetrical; in order to properly sharpen the tool, it is advisable to make a simple device by following these steps:
Thanks to this device, you can attach a drill to the back of the corner with your own hands and thus ensure a back surface angle of 60 degrees. Now that everything is ready, you can get to work. First of all, you need to install the coarse abrasive disc and turn on the machine. Then you need to pick up the drill correctly. To do this, place two fingers of your right hand on the rest, and place the tool to be sharpened on them. As a result, the fingers will serve as a support. With your left hand, grasp the shank of the tool you are sharpening. Turn the drill itself so that the cutting edge that you will sharpen is strictly horizontal.
Now place the tool with its side plane against the back of the angle and bring it with your hands to the working surface of the sharpener. Right hand should remain motionless, and the left one, which holds the tool by the shank, should move slightly in a vertical plane, rocking the drill. Thus, sharpening should occur from the cutting edge to the end of the flank surface.
During the sharpening process, a large number of sparks, so be sure to wear safety glasses when performing this operation.
Using this pattern, make several rocking movements with your left hand up/down. There is no need to strain your hands too much, as the drill will not be pulled out, so just be careful. Having sharpened one back surface, you should rotate the drill 180 degrees with your left hand and sharpen the second back surface in the same way. Upon completion of the work, make sure that the sharpening angle of the drill, i.e. The apex angle is 120 degrees, which is optimal for a metal tool. Also, make sure that the edges and backrests are symmetrical. If the tool is far from ideal, it needs to be sharpened further.
It must be said that as a result of moving the shank in a vertical plane, the rear surface is rounded. Therefore, such sharpening is called conical. It is used for drills with a diameter of more than three millimeters. Correctly sharpening a thinner metal drill is even easier - its cutting part is pressed against the plane of the sharpener and sharpened without any rocking. As a result, the back surface acquires one flat plane. Therefore, such sharpening is called single-plane. The grip of the drill during this processing is shown in the photo below.
After sharpening is completed and the tool has acquired correct form, you need to do some fine-tuning. The fact is that the surface after sharpening with a coarse abrasive is far from ideal. Therefore, you need to install a disk with fine abrasive on the machine and remove all roughness. As a result, the surface should be perfectly smooth.
It is necessary to bring the tool to be sharpened to the working surface of the sharpener smoothly so that there is no impact.
To make sure that the job is done correctly, try drilling a hole, maybe not even a deep one, and make sure that the edge is smooth and even. This is the main indicator of a sharpened tool.
Drills for wood can also be sharpened in exactly the same way. The only thing is that their angle at the apex is made more acute - 140 degrees. Accordingly, the tool is brought to the sharpener at an angle of 70 degrees.
If you don't have sharpening machine, but at the same time you urgently need to sharpen the drill, you can use a grinder (angle grinder). But keep in mind that a sander is one of the most dangerous hand power tools. Violation of safety precautions when working with it leads to serious injuries and sometimes death. Therefore, if you have no experience working with angle grinders, it is better not to try to save money, but to buy a new attachment.
If you nevertheless decide to sharpen drills with a grinder, use exclusively an end flap wheel for these purposes. In addition, it is desirable that the grinder itself be small, i.e. low-power. The sharpening process is as follows:
The disadvantage of this method is that sharpening is carried out “by eye”, so if you have not sharpened metal drills before, it is better to abandon this method. Inept actions can further damage the instrument.
The easiest way to sharpen a drill for wood or metal, which does not require any skills or knowledge from you, is to use a special device for a drill or screwdriver. The device is a nozzle with holes of different diameters.
To sharpen, you need to put the attachment on the power tool, then insert the tool into the hole corresponding to its diameter and turn it until it stops. Special grooves will fix the drill in the working position. Keep in mind that it is extremely important to position the drill correctly in the hole, as only then will the back surface be machined right angle. After installing the drill, you need to turn on the power tool and wait a while until one side is sharpened. Then the tool to be sharpened must be rotated 180 degrees and the procedure repeated.
The disadvantage of the device is that there is a limitation on the diameter. Minimum diameter The drill bit that can be sharpened is 3–3.5 mm, and the maximum is 10 mm. As a rule, the diameter step is 5 mm. However, for domestic purposes this is quite enough. The cost of such a device ranges from 600 to 4000 rubles, depending on the manufacturer. The most expensive products are from German manufacturer Bosch.
All of the sharpening methods described above apply to tools for metal and wood. However, a drill with a pobedit tip can also become dull. At the same time, it behaves in the same way as a metal tool - it drills poorly, quickly overheats and produces an unpleasant high-frequency sound during operation. It must be said that the principle of sharpening Pobedit drills is approximately the same as for metal tools, however, there are some important nuances.
First of all, you need to measure the height of the cutting part of the dull tool. It makes sense to sharpen drills if the height is at least 7-10 mm. If the height is less, it will not be possible to achieve a high-quality result, so it is more profitable to purchase a new nozzle. For sharpening we need a diamond-coated wheel. Please note that the carbide tip does not tolerate high temperatures. Therefore, it is necessary to work at minimum speed.
To sharpen a carbide drill correctly, you first need to correct the edges of the tip, which are the first to “lick off” when working on concrete. The corners of the soldering edges must be even, i.e. at 90 degrees. Then the back surfaces are sharpened to the soldering point, as shown in the photo above. If the carbide tip has worn down to the steel, it is necessary to sharpen the front part. Otherwise, the soft steel will come to the surface of the cutting edge, and accordingly, in this case, no efficiency and quality of drilling will be achieved from the tool.
To sharpen Victory drill and do not overheat it; during operation, use a coolant - water or engine oil.
As with any other drill, be sure to ensure symmetry. The cutting sides must be the same size. If the center of the axis moves, the effectiveness of the tool will decrease, in addition, the holes will be uneven. There is also one more important rule– the harder the tip, the sharper the apex angle should be. For pobedite soldering, this angle should be 170 degrees.
That, in fact, is all you need to know to sharpen drills yourself.
Drilling metal or wood is a job that you do regularly. A high-quality nozzle does not require sharpening for quite a long time, however, there are some mistakes in which dulling occurs ahead of schedule:
The mechanism of hot blunting is simple: the hot edge “releases”, that is, it loses its hardness. Cutting properties deteriorate, which leads to increased friction. Heating increases more strongly, and the process worsens in arithmetic progression.
As a result, we may lose a good and possibly expensive instrument. If you have a drill sharpening machine at hand, the problem is solved on the spot; if not, you have to invent your own sharpening methods.
Locksmith with great experience They sharpen drills by hand, using only a sharpener and a tool. But not all home craftsmen can boast of such skills.
In addition, this method can only restore the sharpness of large-diameter products. Then it is easier to control the angle. The most popular size (3-5 mm) cannot be sharpened this way. Even a template won't help here.
Craftsmen who regularly carry out drilling work will be interested in the variety of sharpening machines for drills offered in power tool stores.
However, such devices (despite the obvious ease of use) are quite expensive. So the “homemade” people run to the store for another Chinese tip. But experienced home craftsmen still use tools from the times of the USSR, which meet GOST standards in terms of strength and durability.
The secret is simple - many old-school locksmiths have in stock homemade machine for sharpening.
IMPORTANT! For most household projects, you can get by with simple sharpening tools. Especially if the word “machine” scares you.
To understand the process, let's take a look at components tip.
Then, by turning the stock, a plane (more precisely, a cone) of the back is formed.
The sharpening is checked on a template and assessed visually. All planes comply with the standard.
A guide is welded to the lower (rear) part of the angle stock to support the drill shank. The stop itself is welded from a coupling and an angle.
Fixation is done using a screw. The stop sets the maximum size of the edge to be ground, and thanks to this, both cutting element The drills are ground symmetrically.
The working edge is sharpened against the direction of rotation emery wheel. In this case, the resulting burr is automatically removed by the running surface of the emery. For sharpening, two or three swings of the stock along the radius of the backing cone are enough.
This type of drill is sharpened according to outer surface emery stone, if necessary, use the lateral (radial) plane - the device can be rotated to any angle.
The drill sharpening machine is attached to the workbench using a clamp. You can fix the base permanently, but in this case you will lose the possibility of precise adjustment.
Drills come in different varieties, but in practice we often use those designed for working with metals. Despite the fact that such a tool is made from special grades of steel and is subjected to special hardening, it becomes dull over time. A thrifty owner will never throw away even the cheapest twist drill, since its functionality is easy to restore on his own, especially since in a private house or garage such a person always has an “emery machine” (a simple sharpening machine). How to sharpen a metal drill correctly will be discussed in this article.
Sharpening varies, 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 you are supposed to work (“hard” or “soft”).
You need to know that there is no universal meaning. For each type of material processed, its own sharpening angle is selected. Approximate values are shown in the table.
Typically used for drills no larger than 3 mm. The disadvantage is that during the work, partial “chipping” of the edge may 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.
Suitable for drills larger than 3mm. The tool is held with both hands, while sequential sharpening of the feathers is carried out (light pressure against the stone with a slight “swing”).
It is advisable to do this after the drill has been sharpened. The task is to remove the smallest nicks and polish the cutting edges. For this, an appropriate stone (“soft”) is used.
For many people, self-sharpening a tool using electric sandpaper is associated with certain difficulties or becomes impossible. The reason is poor vision.
Judging by messages on various forums, neither good lighting nor glasses with large 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 towards products from this country is, to put it mildly, “wary”, such products (for example, “Caliber-ezs 200s”) are spoken of very well by those who have already worked with them. The range of machines is quite large, so there is always a choice (Mikra-10 and a number of others).
To ensure greater sharpening accuracy and facilitate this process, a special device can be made. Its meaning is clear from the picture.
If you don’t have electric sandpaper at hand (and strict requirements for the angle), then you can use a grinder to sharpen the drill.
A video from respected master Viktor Leontiev clearly demonstrates the entire process, so if some of the nuances of sharpening remain unclear, it’s worth watching:
When drilling holes in parts made of metal, the tool used is subject to active wear, which leads to intense heating of the drills and, as a consequence, to their failure. To avoid this, you need to restore them regularly geometric parameters, and a special device for sharpening drills helps to do this as accurately and efficiently as possible. This simple device, which you can make yourself, allows you to quickly and efficiently sharpen dull drills and not spend money on purchasing new ones.
A device designed for sharpening drills is especially relevant in cases where these tools often have to be used on metal, as a result of which they quickly wear out and require regular restoration. When processing wood, the drill used for these purposes practically does not wear out and, accordingly, requires minimal attention to the parameters of its sharpening. For drills, the cutting part of which is equipped with carbide inserts, such a device is also not particularly significant, since they are practically not subject to regrinding and are used by craftsmen until they are completely worn out or broken.
Many experienced specialists do not use sharpening devices at all, completely relying on their experience and eye. However, as practice shows, in such cases it is better to use devices that allow you to mechanize this process. This will ensure maximum accuracy and the required quality of the result.
On modern market We offer a variety of tools for sharpening drills, allowing you to quickly, efficiently and accurately restore the geometry cutting tool even if you have no experience performing such procedures. Meanwhile, you can not spend money on purchasing such devices, but make the simplest machine for sharpening drills with your own hands.
Whatever device or machine is used to sharpen a drill for metal, its quality must be controlled. For this, a special template is used, which can also be serial or made by hand. This template is necessary primarily to control the accuracy of the angles of the cutting part, which are formed during the process of sharpening the drill. Tools used for working with various materials, differ from each other, including the values of such angles. To know exact values the latter can be found in the reference table.
Working with different materials and knowing the angles of the cutting part of drills for such materials, you can make several templates at once and use them to control the correct sharpening of the same drill protruding into in this case as a universal tool.
As the simplest device for sharpening drills, you can use a sleeve with an internal diameter corresponding to the transverse size of the drill, rigidly fixed to a reliable base at a certain angle. When selecting a sleeve for such a device, you must ensure that the diameter of its internal hole strictly corresponds to the transverse size of the drill being sharpened. The tool being processed should not be allowed to dangle in such a hole, since even a 1–2° deviation of its axis from the required value can seriously reduce the quality and accuracy of the sharpening performed.
It is better to immediately equip a homemade device for sharpening drills with a holder made of copper or aluminum tubes, the internal diameters of which correspond to standard sizes the drills you use most often. You can do it simpler and supplement such a device used for sharpening drills with a wooden block. Holes must be drilled in the block corresponding to the sizes of tools of various diameters. The most important element The design of such a device is a handy tool that simultaneously solves several important problems:
A similar device based on an oak block with holes of different diameters was used by our grandfathers, who used it to sharpen drills with high quality and precision. The main task that a homemade machine or device used for sharpening drills must solve is to correctly orient the cutting part of the drill being processed in relation to the working surface of the grinding wheel.
To make a homemade machine for sharpening drills, you can use various designs similar devices. The corresponding drawings are easy to find on the Internet. Moreover, if you understand the operating principle of such a device, then you can make your own sharpening machine according to your own design.
Drawings of fixture parts
Promopore Promopore platform Movable platform
Drill bit mount and stop screw Turntable Bolts, nuts, pins and washers
There is an important rule that must be observed when working with such a device: during its use, the drill being sharpened should not rotate around its axis. If the tool rotates even at a small angle, sharpening will have to be done again.
After sharpening the drill, it should be allowed to cool. Then you need to check its restored geometric parameters using a template. It must be borne in mind that the cutting edges of the tool may differ from each other in length by no more than tenths of a millimeter. It is especially important to comply with this requirement for drills with a small diameter.
Among the mistakes made when sharpening drills using such a device, two of the most typical ones stand out.
As a basis for the manufacture of a sharpening machine for spiral-type drills, you can use any serial sharpening unit that can operate without runout and withstand significant loads. When equipping such a machine with additional devices, the following requirements must be met.
In the manufacture of this device for sharpening drills, complex technical devices and scarce materials that will have to be purchased additionally. All components can be found in almost any home workshop or garage. As equipment and tools with which such components will be modified before assembling the device, you can use a regular grinder and a welding machine.
Since the stop of such a device must be oscillating, which is necessary for sharpening drills in a semi-automatic mode, a loop connection should be used to fix it. When selecting a tube, bracket and bolt for the fastening unit, you should keep in mind that there should be no play in the device. The homemade product of the proposed design has two degrees of freedom.
The platform of such a device, on which the drill being processed is fixed, has the ability to rotate along a vertical axis, making it possible to change the sharpening angle of the tool. In addition, the tool rest, resting on a horizontal axis, can make oscillatory movements, which ensures correct articulation during sharpening.
For the manufacture of structural elements such a device is used sheet metal of various thicknesses, namely:
The tool rest, on the top of which the support plate is installed, must be securely fixed to the body grinding machine. For this, an additional metal “cheek” is used, connected to the device bracket.
The guide plate, on the surface of which it is necessary to make a triangular groove designed to accommodate the tool being processed, is fixed on the support plate using a screw connection.
Device and design features The drill sharpening device in question allows it to rotate up to 90°. Thanks to this ability, you can sharpen drills using this device using almost any of the methods used today.
The drill, sharpened using such a device, fits into the guide groove and can move freely in it in the longitudinal direction. In this case, the sharpening angle of the tool does not change.
Since the upper surface of the support plate is located slightly above the axis of rotation of the grinding wheel, when using such a device, optimal shape sharpening the back surface of the drill.
The process of sharpening drills using such a device is as follows.
The process of working with such a device is well demonstrated in a video that is easy to find on the Internet.
Despite the simplicity of the design, this device provides high accuracy sharpening being performed, for quality control of which you don’t even need to use a template. If you fix the swing plate of this device at a fixed angle, it can also be used for sharpening drills equipped with carbide inserts.
In order to successfully sharpen metal drills, most of which are made of high-speed steel, it is necessary to use a sufficiently hard sharpening wheel. For this purpose, you can use an abrasive tool made of silicon carbide. Such wheels, which can be identified by their green color and marking 64C, should have a grain size in the range of 8H - 16H. When using discs made of this material, you must keep in mind that they become very hot during operation, so you should not allow the drill to be sharpened to be in prolonged contact with the abrasive tool. To prevent overheating of the drill when sharpening it on such a disk, the tool must be regularly cooled using an aqueous solution of soda.
I admit, sharpening a tool has always caused me quiet horror. You need to think not only about the rotating grindstone, which acts as a source potential danger, but also keep the sharpening angle... I think the article will be useful for beginning brainiacs, and for experienced comrades I kind request supplement the information below or tell us about your method of maintaining the sharpening angle.
Materials
Tools
Draw two straight lines on paper at an angle of 59 degrees. The goal is to sharpen the drill at this angle.
Using a small tool, transfer the angle of 59 degrees to wooden block. I used hardwood as a blank. The thickness of the bar is 15 mm. The guide will be a screw with a fine thread pitch for a slotted screwdriver, so the through hole should be slightly smaller in diameter than the diameter of the screw so that it is screwed tightly into the block. Drilling into wood with a drill is easier when you start drilling at an angle. We determine by eye the place where it is most convenient to place the screw.
We screw the screw into the block. You should determine in advance the maximum diameter of the drill that will be sharpened. For this crafts the drill diameter will be greater than 15 mm. Therefore, you should choose a screw of sufficient length so that it passes through the block and protrudes halfway from the largest diameter sharpened drill.
If the angle at which the screw exits the block does not match the reference line, drill another hole and try again.
Turn the screw a few turns so that the end of the thread is above the center of the drill.
Once you have sharpened one side (using the threads of the screw as marks), turn the drill bit halfway and look at the marks on the screw. Repeat the operation for the other side of the drill.
As for sharpening drills, the website provides a detailed article. In addition to the material presented in it, I suggest watching the video of the English-speaking Kulibin.
Thank you for your attention)
