Modern market offers customers a huge number of drills different types. Some of them are used exclusively for wooden structures, let's figure out how to choose them correctly and how to sharpen a wood drill in the best way.
When it becomes necessary to choose the right drill, the first thing you need to pay attention to is the color. So, for example, each shade of the product is responsible for the type of final processing, which shows the life of the drill and its strength.
- The worst option can be considered gray products, which are not processed in any way and their performance parameters are quite low.
- The color can be golden, which indicates titanium coating and a fairly long service life.
- Black drills treated with steam during creation are no worse in performance.
In addition, it is worth carefully visually examining the object. If there are visible signs of deformation on it, then it is better not to use such a product. It is important to choose a drill without a single scratch or crack; its surface should be perfectly flat and smooth.
Types of wood drills
Typically, high-quality drills are used by experienced craftsmen who require Various types products for creating holes in wood. These could be holes, for example, for tenons, bolts or dowels. Moreover, the drilling process itself can be very diverse in quality, which will lead to thoughts about how to properly sharpen the drill after use and whether it will have to be sharpened at all.
The most common types of drills today include: screw, spiral, feather, center, ring and Forstner drills.
Screw
If you need to drill wood across the grain, without once again asking yourself the question of how to properly sharpen a drill for wood, then it will come in handy screw drill with fine thread at the end. They can reach up to 50 millimeters in diameter. A special screw shape will help remove chips from the work site in a timely manner and thus not overheat the rod. Depending on the required hole depth, you can purchase drills longer than a centimeter, while minimum size– 400 millimeters.
Spiral
A spiral product can immediately be distinguished by a perfectly polished milled spiral with an edge that prevents any movement of the rod to the side during operation. It is thanks to the spiral shape that they can easily drill holes in veneer structures. The diameter of the corresponding drills reaches 52 millimeters, and the smallest can be found at 3 millimeters. In order to accurately target the intended drilling location, the tail of the product is equipped with a conical shape, which gives a lot of convenience.
If, when purchasing, the choice fell on twist drills, then you should always remember the relationship between the diameter of the product and maximum quantity rpm it can produce. Otherwise, the service life of the product will be sharply reduced. If you need to process hard wooden surfaces, it is better to set a maximum of 900 rpm with a drill diameter of 14 millimeters or less. But for soft wood, you can set the drilling tool to 1800 rpm.
Feathers
The most common type of drill is the feather drill. It is this that makes you think about how to sharpen a feather drill for wood, and is most often used for repair and construction work. It is the most convenient and has various options in diameter.
It has only one important drawback: this shape of the drill does not facilitate chip removal and the drilling process becomes significantly more complicated, especially when a hole with great depth. That is why experts recommend using this type of drill when working with wood boards or thick boards, where the drilling process will occur as efficiently as possible.
A special type of tip for a feather drill or a similar product with an extension can correct the situation. This extension cord has a hexagonal shape and can be used for other types of drills. In this case, the diameter of the final hole can reach up to 52 millimeters.
Center and ring
But center drills are useful for creating perfectly even through holes on a wooden surface. Typically, such products take the form of a 50 mm (minimum 12 mm) rod with a cutting edge at the bottom, reaching a length of up to 150 mm. Of course, it will not be possible to make deep enough holes. For this purpose, ring drills are suitable, which look similar to a crown or a ring with teeth. They are usually sold as a whole set in the form of attachments with a centering drill and a single base.
Forstner drills
When it comes to repairing or creating furniture, and not about thoughts with the question of how to sharpen a feather drill for wood, then you can immediately safely go for Forstner drills, which are best suited for this task. They allow you to drill completely blind holes with a perfectly flat bottom. In this case, the diameter of the product reaches from 10 to 50 millimeters. The drill itself is coated with a specialized alloy, which serves as protection and increases service life.
Correct sharpening of the drill
Before you start directly sharpening an expensive and high-quality drill, you should try your skills on old, used products. Thus, if the result is negative, the old drill can always be used as a consumable. When your hand is full, you can switch to a new drill without fear.
For the most correct sharpening of a wood drill, you should follow this geometric parameters. This means that it is important to maintain the factory sharpening angle. Sometimes the result can be just like this – perfectly sharpened for a hammer drill. The drill itself can be processed either manually or using an electric sharpener.
Manual sharpening
When sharpening by hand, a mild steel file is used. Moreover, it is worth starting the processing process with a tool with a wide notch pitch, processing both the cutting edge and reverse side. After this, you can bring the drill to perfect condition using a file with a fine notch.
Sharpening with an electric sharpener
When drill sharpening and happens in “automatic” mode using an electric sharpener, it is very important to have a cold water(in a container or flow-through), since it is necessary to constantly cool the rod. This will keep the product from overheating and damage.
With this option, the drill should be sharpened on the edge of the sharpening disk.
Once the required drill geometry has been achieved, it is worth finishing the drill at low speeds.
Homemade drill sharpening machine
If you don’t have a sharpening machine at hand, you can easily make one yourself.
- It is necessary to firmly install the grinder in a comfortable position. A stationary frame with a motor speed of up to 1500 rpm (with a power of 200 W) is also suitable.
- Basis for homemade machine Thick plywood or wooden beams may well serve.
- For more correct sharpening, it is necessary to eliminate any vibration of the engine and create conditions for a smooth transition to different speeds. To achieve this result, you can use an abrasive wheel.
Step-by-step instructions for sharpening a drill
The result of the above actions is a certain scheme of actions:
- Guide the drill to the edge of the grinding machine disk.
- Mandatory adherence to the factory sharpening angle of 95 degrees.
- To improve the quality of sharpening, the drill should be secured in a washer, the rear edges of which should be tucked a couple of millimeters.
- Once sharpening is completed, it is worth continuing work at lower speeds.
- After this, you can cool the sharpened product and test it for functionality.
When sharpening a drill, it is important to understand that a person must have very good eyesight. Therefore for best result It is necessary to organize high-quality lighting of the place of work. If the rules are strictly followed, a sharpened drill will last a very long time and will always be a “savior” during repair or construction work.
In the arsenal of any master there is a set of tools that can be useful for solving a wide variety of household problems. repair problems. These include a set of screwdrivers, an electric drill with a set of drills, and a hammer. In this case, it is necessary that the screwdriver attachments be universal, that is, suitable for any type of screw or bolt. The same applies to drills. IN standard set includes drills that may be useful for working with various materials, for example, wood, concrete, metal.
And over time these Consumables become dull and cannot perform their functions to the required extent. Each of types of drills there are features in sharpening. Some of them can only be sharpened using sophisticated machinery and equipment. But you can handle the process of sharpening a wood drill yourself at home. This requires patience and some simple skills.
Independent choice of drill
When choosing and purchasing drill bits for a drill, first of all you need to carefully inspect the tool for cracks and other external damage. These defects must be completely absent. By the color of the drill, you can determine how the final processing was performed. The strength and other performance characteristics of the tool depend on this. If the drill is black, then it was treated with high-temperature steam, which increases strength.
The position of the drill when sharpening on a grinding wheel.
When the color was golden yellow, the drill was treated to relieve stress. When a drill is treated with titanium nitride, the drill becomes bright yellow. After titanium coating, the service life increases significantly. The drill, which is not subjected to any processing, has a dark gray color.
Most often, a drill comes with a set of drills. It may include tools of various lengths, diameters, and processing methods.
Drills according to their application can be divided into:
- for woodworking;
- for concrete structures;
- for metal parts.
Each type may differ in appearance and color. But there are also subtleties. So, for example, to drill wood, drills can be made in the form of a spiral, serpentine, or feather-shaped.
The twist drill comes in diameters of 3-52 mm. The special feature of this tool is that the double tape can ensure precise guidance along the hole, regardless of the depth, preventing it from slipping. The chips are removed in a timely manner and the spiral does not become clogged. It is used to drill holes for dowels in monolithic wooden slabs of various types of wood, thick plywood sheets, as well as soft wood.
Threaded point, slotter and hex shank are the features of the serpentine drill bit. The spiral is carefully ground and milled. It is used to make holes in slabs that are lined with veneer.
A drill bit with a feather tip can be used for household purposes on various types of wood. It is very convenient to remove it from the drill clamp if you need to make many holes of different diameters. It can be used to drill into hard or soft wood.
The quality of the resulting hole will directly depend on how correct the choice of element turns out to be. Your drill kit should have a long piece to drill through thick wood. It is very important to consider the size of the electric drill. With a length of 45 cm and a diameter of 10 mm, it has sufficient weight even when operating at high speeds a regular drill You may experience discomfort. Therefore, to work with such a drill, it is better to use a drill mixer that has low speed.
A twist drill bit can work against the grain in wood. Their diameters can be 10-50 mm, length 400-1100 mm. The longer the drill, the longer it should be equipped with threads. It is this that will ensure easy removal of chips during operation.
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Additional points
As an alternative to a long threaded drill bit for making required holes can be used feather drills with extension cord. But of this type drills have a significant drawback: with a large hole length, it is difficult to remove chips. This extension has a hexagonal shape and can be used for other types of drills. The diameter of the hole that will be obtained as a result can be 10-52 mm.
For woodworking, in addition to these types (spiral, serpentine, feather type), ring drills are also used. This is a specific type of drill that is most often used for holes in furniture parts. In addition, with the help of such drills you can drill holes sufficiently large diameter, which none of the other types can do. The drill itself looks like a ring with teeth. Such drills are sold in a set, which includes attachments and a base for attaching them.
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Correct sharpening of the drill
When the product becomes dull, the question arises, where. Sharpening yourself is possible, but this requires certain skills. If there are none, then to acquire them you can first sharpen elements that are quite old, which can be thrown away if unsuccessful. After all, if you do not follow the sharpening technique, then further use It is impossible to restore the product, nor can it be restored. Drills designed for woodworking are especially easy to sharpen at home. This is due to the peculiarity of the design of this instrument, as it is made of softer steel. Then the place to sharpen the drill will be your home workshop.
For sharpening, you need a sharpening machine, which must be constantly supplied with water.
A jet of water will prevent the drill metal from overheating while performing work. If you don’t have it at home, you can use a file. But processing the drill by hand will require a lot of time and patience.
When sharpening, you must strictly observe the original geometric dimensions and not disturb the configuration features of the tool. Namely, the degree of its preliminary sharpening, which was performed during production.
If a sharpening machine (sharpener) is used, then the process itself is performed with the edge of a sharpening disk. To maintain the required accuracy of geometric quantities, you can use a special additional tool. A drill is inserted into it and clamped. This will make the sharpening job easier and protect your hands from possible burns from an overheated drill. To avoid injury to your hands, it is recommended to use gloves while working. After the preliminary sharpening has been completed, it is necessary to bring the cutting edge to perfect condition. This can be done on the same machine, but at reduced speed. It is after finishing that the drill will be finally sharpened and ready for further use. Correctly performed sharpening can provide long term operation of the tool within the limits of the requirements: do not make nicks in the wood when drilling, guide the chips along the body of the drill.
Sharpening a drill at home is not difficult if you know how. The main difficulty in this matter is maintaining the correct angles. After all, at home, as a rule, there are no special mandrels and conductors. There is only a sharpening machine. At least, we will proceed from such conditions.
The only equipment we have is an electric sharpening machine. But just because it exists does not mean that you can sharpen drills on it. It is necessary that the sharpening disk has the correct shape - that is, the shape of a cylinder with a smooth, not rounded edge. A convex edge with ground edges may result in incorrect sharpening.
If the disk is very worn out, it is better to replace it with a new one or correct it with a special CBN “pencil”, if you have one on the farm. It is very good if the disk is balanced and does not produce beats or vibrations (in fact, this is a mandatory norm). Only the peripheral surface of the disk is involved in the work, not its ends.
There is a temptation to use the flat side surface of the disk. But after several sharpenings it will lose its shape and fixing the stone after that will be much more difficult.
Sharpening auger for concrete
The hammer drill has a carbide plate as the cutting part, inserted into a slot at the working end and secured 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 apex of 130–140 0.
With standard sharpening, the front edge of the cutting edge (directed in the direction of rotation) is inclined to the drill axis at an angle of 30 0, and the rear edge is inclined at an angle of 60 0. When manually sharpening, without special tools, you can focus on the entire, unworn part of the edges and reproduce their angles of inclination.
Sharpening process
We start sharpening from the front edges. We position the drill near the peripheral surface of the stone so that the cutting edge is parallel to the axis of the sharpener and directed upward, and the edge is parallel to the surface, and on a short time Lightly press the drill against the sharpener. A clearly visible mark remains on the metal, which shows whether its position was chosen correctly. The plane of the test section should coincide with the plane of the edge, and the spot of the section should be located in the center of its unworn part, without significant displacement. Finding it empirically correct position, remember it and start 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 a sharp edge. Remember that you still have to grind down the back edge, and then the edge will “fall into place.”
First, the front edges are sharpened one after another. Then you need to check their symmetry. This is done visually, in the light, by placing the drill head near the edge of an object. The edge should be smooth or concave, but symmetrical. You can make a special template for testing. If there is asymmetry, a shorter edge is additionally ground down.
After this, the back edges of the edges are also ground down one by one, followed by checking for symmetry. The symmetry of the arrangement of the edges is also checked when viewed from the end, along the axis of the drill. At correct sharpening they are parallel, and between them there remains a bridge 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 roundings or cavities on them, the entire sharpening cycle must be repeated.
Add-ons
When sharpening, it is important not to overheat the tool. To cool, it is periodically dipped in water. A container of water should be kept near the machine. Do not press the drill against the sharpener 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 the edge is reduced.
To work on soft materials without impact, for example on brick or tile, the cutting edges are brought “to zero”, without a jumper, and their sharpening angle is reduced to 30–35 0.
How to hold the drill while processing
Since, according to the conditions of the task, we do not have devices for precise positioning of drills, all hope is for own hands. There are a few simple techniques How to achieve a “steady hand”.
It is best if, when sharpening a drill, you can rest it on a tool rest - a special “table” fixed in front of the sharpener. If you cannot achieve the desired position with direct support on the tool rest, you can hold the workpiece in your hands, but be sure to lean on it:
- fingers on the rest;
- with your wrist or hand on a workbench, on your knee, on any stable and conveniently located object;
- elbow or forearm on a workbench or knee.
As a last resort, 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 a way to hold the tool as tightly as possible with minimal effort.
When fixing the drill during operation, you should remember its position not only visually, but also by the sensations in your 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 down. 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 both hands. One near the sharpener, the other by the shank. The fingers of the hand closest to the sharpener (leading) rest on the rest. If it is not there, you need to find any support, as described above.
The drill is positioned at an angle to the working surface whetstone: 60 0 horizontally (half the angle at the apex) and about 10 0 vertically. The sharpened cutting edge is directed upward and located horizontally, parallel to the axis of the stone. The position can be selected when the machine is turned off, according to the shape of the gaps between the edge and the sharpener when viewed from above, and between the sharpener and the back surface when viewed from the side. To more accurately set the sharpening angle, you can clearly mark on the tool rest visible line at the right angle.
When sharpening, the drill is pressed against the sharpener by the cutting edge, and then, without changing the pressure and horizontal angle, it is tilted with the shank 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 is rotated around the longitudinal axis by 180 0, and the operation is repeated for the second edge. The tool is rotated only with your fingers, without changing the position of your 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 is shorter, it needs to be sharpened again. The equality of the angles is checked visually - against the light or using a simple template; the length of the edges can be measured with a caliper.
Additional processing
When sharpened correctly, the cutting edges do not meet at the top; a short bridge remains between them. To reduce resistance to entry into the material, the bridge is ground off with the angle of a sharpening stone or a diamond file. Grinding is carried out on both sides, symmetrically, at an acute angle to the axis of the drill, and the edge of the resulting groove is located at an angle of 30 0 to the cutting edge. The purpose of this operation is to shorten the jumper, but not to grind it off completely! Without it, the drill will not be centered upon entry.
The lintel is stitched using drills with a diameter of more than 3 mm. But in practice, for simple work Without high loads, the jumper, as a rule, is not ground down even with a diameter of 10 mm or more.
Checking the sharpness
After sharpening, you need to check the tool in operation and, if necessary, correct it. There are several signs that indicate sharpening errors.
- Poor alignment at the entrance; during operation, beating is noticeable - asymmetrical sharpening of edges or bridges.
- When working, you can hear the squealing of metal, the drill gets 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, chips quickly form on the cutting edges - the sharpening angle of the edges is too small (excessively sharp edges).
Signs of proper sharpening:
- clear centering upon entry, stable work, no beats;
- entrance to light material, the chips come out in the form of identical “spirals” from both grooves;
- The heating of the drill is low.
Wood drill sharpening
For drilling wood and wood materials There are several types of drills. Here we will 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 may be the same. But wood has a fibrous structure. When drilling it, the cutters in different directions interacts with the material differently. The consequence of this may be scuffing and chipping on the surface of the workpiece. To avoid this and get a neat, even hole, use a special sharpening of the drill, with a center and trimmers.
The first to come into contact with the material is the centerpiece - a narrow spike located along the axis of the drill. As it goes deeper, it centers the tool and keeps it from moving laterally. Then the scorers come into play - the side incisors protruding above the cutting edges. They cut wood fibers along the contour of the hole and prevent the spread of flakes beyond its boundaries. The contoured, virtually isolated material is extracted by the main blades.
Geometry of the working part
The angles of inclination of the center faces to the drill axis are 10 0, the inclination of the inner edges of the scorers is 30 0, the outer edges of the scorers coincide with the side surface of the drill. The angle of depression of the rear surface of the cutting edges is 25 0 . The height of the centerpiece and scorers above the cutting edges depends on the diameter of the drill, but the scorers are always lower.
For example, a drill with a diameter of 10 mm should have a center height of 3.5–4.5 mm, and scorers should be 1 mm high. The width of the base of the center is about 1.5 mm. For recommended parameters for different diameters, see Tables 1 and 2 of Appendix 1 to GOST 22053-76.
What to sharpen
To perform such a complex sharpening you need a specially shaped stone. If you have a “pencil” for straightening abrasive discs, you can give a standard sharpening disc a trapezoidal profile (grind one edge to a cone) and use this stone for sharpening only wood drills.
You can also use a grinder disc by installing it on a sharpening machine. For different mounting diameters, an adapter can be ordered. Another option is to use a grinder. But it must be securely fastened.
Sharpening is a familiar job
The process of sharpening a wood drill is, in principle, no different from sharpening other drills. The same techniques are used for selecting the desired angles, fixing the tool and controlling symmetry. If you just need to sharpen a dull drill, then with good equipment there should not be any big difficulties. If you need to make a wood drill from a standard one, then you should first practice on old drills, which you don’t mind using lime for training.
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.
When is sharpening required?
While wood drills can be used for a long time and still remain sharp, metal tools become unusable very quickly. Of course, an experienced craftsman can identify 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:
- during the drilling process, creaking and whistling occur;
- the tool heats up much faster than usual;
- the quality of the hole is low - there are jagged and burrs;
- chips come out of only one spiral groove (this sign may also indicate improper sharpening).
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.
Main parameters of the part
So that you can properly sharpen the tip, first of all, let's look at its main elements, which include:
- cutting part (cutting edge), formed by the convergence of the groove surface and the rear surface;
- the front surface, which is located under the cutting edge;
- back surface, which is located behind the edge:
- a bridge located between two rear surfaces.
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:
Compliance with these values will allow the cutting edge to always be the first to contact the surface of the workpiece, which will ensure maximum efficiency tool. 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. An angle that is too obtuse will reduce the effectiveness of the drill.
Sharpening on a sharpening machine
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:
- draw straight line on a tool rest at an angle of 60 degrees relative to the working surface of the abrasive disc. The line should be located opposite the working surface;
- secure the scrap to the tool rest metal corner, aligning it along the intended line, as shown in the photo below. Those. the corner should also be located at an angle of 60 degrees in relation to the working surface of the circle. You can use a clamp to secure the corner. If you sharpen frequently, you can drill holes and secure the angle with bolts.
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 sharpen more thin drill for metal it is even simpler - its cutting part is pressed against the plane of the sharpener and sharpened without any swaying. 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 the correct shape, you need to perform 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.
No sharpening machine - grinder for all occasions
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 grinder for these purposes. petal circle. In addition, it is desirable that the grinder itself be small, i.e. low-power. The sharpening process is as follows:
- 1. The grinder is placed on a horizontal plane with the disc up so that the disc is also horizontal. The tool must be held firmly with your left hand, and the power button should also be controlled with the same hand.
- 2. Then the drill must be brought to the disk and sharpened, trying to maintain the factory angles. The grinder should be turned on at minimum speed.
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.
We use the device - when theory is not needed
The easiest way to sharpen a drill for wood or metal, which does not require any skills or knowledge from you, is to use special devices 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.
A few words about repairing concrete drills
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. Keep in mind 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 carbide brazing ground down to steel, the front part needs to be sharpened. 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 a Pobedit drill without overheating it, use a coolant during work - water or machine 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 Pobedit soldering this angle should be 170 degrees.
That's basically all you need to know to self-sharpening drills
To drill into metal or wooden part hole, use drills. However, they require sharpening during operation. If you do not sharpen the drill, then working with it will take a long time, and the quality of the hole will be unsatisfactory. We'll talk about methods for sharpening drills for wood and metal later.
Features of choosing a drill for wood and metal
In the process of choosing a particular drill, you should first of all visually inspect it. There should be no cracks, chips or other deformations on its surface; it should be smooth and even. In relation to the color of this device, the type of final processing is determined, which affects the strength and service life of the drill.
Black drills have excellent performance characteristics as they are processed using steam. If the color of the drill is yellow or gold, then it is treated with titanium plating. This process allows the drill to release excess stress. In addition, the service life of the drill increases significantly.
Drill gray indicates that it has not been processed, therefore the performance properties of such a tool are at a low level. When you buy a drill, you receive a set of drills that differ in diameter, length and type of use.
Most often, drills are divided into tools used for drilling holes:
- on concrete surfaces;
- on wooden surfaces;
- on metal surfaces.
Each type of drill has individual characteristics appearance and colors. For drilling wooden surfaces drills in the form of a feather, snake or spiral are used.
The most common diameter of a screw drill for wood is from three to fifty-two millimeters. This tool has a double tape, which ensures accurate hole drilling. In this case, slipping of the drill during operation is excluded. To remove chips, the drill has holes in the spiral through which it exits. It is suitable for drilling holes for dowels, monolithic and wood slabs, plywood sheets, etc.
The serpentine version of the drill is distinguished by the presence of a carefully polished and milled spiral. It is used to make holes in parts made of veneer.
The feather drill for wood has a wide range of applications. It is easy to use and comes in a variety of diameters. Used for both drilling soft wood, and for harder wood species. A feather drill for wood is an excellent and versatile option for drilling almost any hole.
Screw drills provide drilling against the grain of the wood. Diameters of drills for metal and wood screw type They range from one to five centimeters. The length of such a drill is from four to ten centimeters.
The quality of the resulting hole is determined, first of all, by the correct choice of drill for a particular material, as well as the level of sharpening of this drill.
Sharpening a wood drill: work plan
In answering the question of how to sharpen a wood drill, there are many nuances that should be taken into account. First of all, you should determine whether the drill is really dull; perhaps the reason is its breakage or wear. Signs that a wood drill needs additional sharpening are, first of all, the fact that the work of drilling a hole takes much longer, the holes are uneven and of poor quality. Also, such a drill heats up very quickly and becomes deformed when exposed to too much temperature.
If you have no experience in sharpening wood drills, we recommend that you initially practice on old and already worn drills. If sharpening is performed incorrectly, further operation or restoration of the drill will be impossible. A large diameter wood drill bit can be sharpened better than drill bits used for drilling metal surfaces. Since wood drills are made from more pliable and soft materials. IN in this case, to sharpen such a drill, household tools are sufficient.
During the sharpening process, you will need a sharpening machine and a container of water used to cool the drill. Water will prevent overheating of the steel and deformation of the drill during the sharpening process.
If you do not have a machine for sharpening drills, then use a regular file. However, in this case, the sharpening process will last several times longer. The main rule for high-quality sharpening of long wood drills is compliance correct proportions And geometric shapes. That is, the shape of the drill should be exactly the same as after its purchase. An annular wood drill must be sharpened to a certain sharpening angle.
When using the sharpening machine, in this case, you should carefully place the drill against the sharpening disk. To ensure that the required values are as accurate as possible, use additional devices. This may be a device into which a drill is installed and clamped.
Thus, the drill is in special mechanism and the risk of burns due to its heating is reduced. In addition, in order to avoid injuring your hands, mandatory Wear gloves before sharpening. After preliminary sharpening, the edge is gradually brought to a smooth shape and ideal condition. This is done using the same machine, but at low speeds. After finishing, the drill can be used for its intended purpose.
If sharpening is done correctly, the service life of the drill increases significantly.
Sharpening a wood drill video at the end of the article.
The technology for sharpening a wood drill involves performing the following actions:
1. The sharpening angle of the wood drill is ninety-five degrees. This value, must be maintained.
2. The drill is installed exclusively on the edge of the sharpening machine.
3. In order to increase the accuracy of work, we recommend installing a drill inside a special tool, for example, a washer.
4. Tuck its back edges a few millimeters, making sure each edge is even.
5. After sharpening, you should reduce the speed on the machine and continue working.
6. Try to keep the bridge on the drill very thin. Thus, the ease of working with the tool increases. If the drill is too thin, then the jumper does not need to be sharpened.
Types and sharpening of metal drills
Metal drill bits vary in thickness, size, shape or application. A spiral drill for metal can be:
- a conical drill for metal is distinguished by the presence of a conical shank; a conical drill for metal has a diameter of six to sixty millimeters;
- a step drill for metal is rare;
- metal drill with a cylindrical shank;
- long square metal drill bit.
In relation to the final processing of metal drills, there are:
- untreated differ in the standard color of steel;
- processed with steam, have a black color;
- golden color, capable of transmitting excess voltage;
- Titanium drills have a bright yellow color.
For drill manufacturing For metal, high-speed steel, tool steel with cobalt additives, alloy steel, and special types of metals are used.
Using cylindrical twist drills Aluminum, copper, zinc or magnesium alloys are processed. Titanium alloys are processed using special equipment and A-class drills.
Conical metal drills are used for drilling carbide metals. They differ in relation to the grade and type of steel from which they are made. The processing of a particular metal depends on the sharpening angle of the drill. At the same time, there are the following requirements for the sharpening angle of a drill for metal:
- if the drill is made of soft or non-ferrous metal, then the sharpening angle is from eighty to ninety degrees;
- if the metal has an average degree of hardness and for cast iron metals, the sharpening angle is from one hundred sixteen to one hundred and twenty degrees;
- for very hard steel, the sharpening angle of the drill is one hundred thirty one hundred and forty degrees.
How to sharpen a drill for metal: technology and features of sharpening
During the operation of any drill, it becomes faulty and needs to be sharpened. In order to save money on purchasing a new drill, especially if it is made of high-quality steel, we recommend sharpening it.
Metal drills, unlike wood drills, are made of high-quality steel, the sharpening of which requires special skills in working with a sharpening machine. The most optimal and common drill diameter is sixteen millimeters. The easiest way to sharpen such a drill is to use a sharpening wheel. If there is no such equipment in the garage, then you should install a drill in electric drill, fix it in a stationary position, take a grinding stone and start sharpening.
Please note that you should wear a protective mask over your eyes and gloves on your hands, as the drill gets too hot during the sharpening process. Prepare a small container of liquid that will gradually cool.
Water can be replaced with machine oil. If you do not cool the drill during operation, it will become deformed under the influence of high temperature.
The sharpening process must be sequential, first the back of the surface should be processed. Try to keep the drill bit tight to the surface. Watch the sharpening angle of the drill, it should be at the same level. If you examine the drill from the side, it should resemble a cone shape.
Next you need to process cutting part drill. Also, it is necessary to maintain a certain angle of the drill. Next, you should finally finish the back surface. Follow the direction of the jumper; it should be no larger than 0.4 mm in size for small drills. If the diameter of the drill is large, then the jumper can be up to one centimeter.
Before starting work, we recommend practicing on old drills. After gaining the skills to work with a grinding wheel, proceed to the actual sharpening of the drill. Please note that drilling is not done with the tip itself, but with its sides, so they must also be perfectly sharpened.
If the drill has a pobedit tip, then the technology for sharpening it is slightly different from the standard one. We suggest that you familiarize yourself with the recommendations for sharpening a metal drill:
- try to keep the edge of the drill parallel to the working surface of the grinding wheel or stone;
- sharpening should be done gradually, do not press the drill onto the circle;
- try to keep the edges the same length;
- O high quality sharpening of a drill for metal is evidenced by the surface of the drill, on which there are no reflections.
The first sharpening option is single-plane. This sharpening is used if the diameter of the drill does not exceed three millimeters. This technique is carried out with extreme care, otherwise the drill may crumble. The tool is placed on the circle and moves in parallel with its movements.
If the diameter of the drill exceeds three millimeters, then a conical sharpening should be used. In this case, the drill must be held with two hands, gradually sharpening its feathers. The drill presses easily against the stone and wobbles a little during the sharpening process.
After sharpening the drill, it is necessary to perform fine-tuning. With its help, it will be possible to get rid of small nicks and grind the edge. For these purposes, it is recommended to use a special soft stone.
Please note that the person sharpening must have good eyesight. Also, during the work process it is necessary to organize good lighting. In order to ensure greater sharpening accuracy, it is necessary to produce special tool. It will help fix the drill in a stationary position in relation to the grinding wheel.
Sharpening a drill for metal video: