A hacksaw is one of the most important tools in the household. It is often necessary to saw off, trim or shorten something, and a hacksaw is not always at hand.
Today's homemade products are a kind of power tool designed for sawing small pieces of wood. At the heart is a wide blade from a hacksaw for metal. Similar ones exist with a large tooth, for faster sawing.

We collect materials and tools

For work we need:

Wooden block 30x7 cm, about 2 cm thick;
The blade for a hacksaw for metal is wide;
A small piece of mild steel sheet;
DC motor for simulation;
Wooden lath for traction and backing:
Gearwheel with 3 mm bore;
Push-button switch;
Socket for the adapter connector;
12V adapter;
Superglue and carpentry (PVA);
A piece of an old bicycle camera;
Several wires, bolts and nuts, and one window handle.

Instruments:

Drill with core drill for the diameter of the motor housing;
Impeller or electro-emery cloth for grinding the teeth of the blade;
Hot glue;
Soldering iron with solder and flux;
Spanners;
Knife, screwdriver, pliers.

Putting together an electric hawk

The wooden block will serve as a handle for our electric hacker, so it needs to be prepared. It's not just a piece of rough wood. It is desirable that it be evenly planed, with the same width of edges and planes.

We take a drill and make a hole in it with a crown cutter for the engine.

Now we are preparing the hacksaw blade. He needs to grind his teeth literally to the middle. This must be done on both sides using a turbine with an abrasive nozzle or an electric sandpaper.

Next, we work with a piece of steel, which must be bent like a scabbard from the edges. It is in such "scabbards" that the worn-off part of the hacksaw blade will move. Mark out a piece of steel and bend it with pliers.

To prevent the blade from adhering too much to the handle, it is necessary to secure it through the gasket. We make it from a thin wooden plank, which we cut to the size of the iron guides for the canvas. We put this piece of plank on wood glue or PVA.

We attach the guides, and place several mounting holes with a marker. You will need to drill them with a drill.

We fasten the guides with two self-tapping screws, and cover the handle on all sides with spray paint. We also do not forget to paint over the traction made from the remainder of the wooden plank.

It was the turn to fix the engine. The hole for it is made with a margin, so to keep it firmly, we use a piece of an old bicycle camera as a gasket. We cut off the excess pieces of rubber protruding from both sides with a knife.

For the traction to work, we will need to fix a small plastic gear on the engine shaft. We will use superglue for this.

We will put the connection of the gear and the thrust on the bolts. To do this, we fix the driving bolt at the base of the blade, and tighten it with a nut and a lock nut so that it does not unwind.

Make a hole in the gear with a small drill for the next connecting bolt. We insert it into the gear and also tighten it with nuts.

We mark the rod-bar according to the minimum size between the two bolts, and drill a hole in it for them.

We fix the rod in the same way on the nuts, but so that it moves freely on a pendulum stroke.

On the upper edge of the handle, we fix the window handle for the convenience of working with the tool.

Despite the variety of power tools for woodworking, hand saws are still popular with DIYers. The advantages are obvious - low cost, compact size and instant readiness for work (especially if there is no power source).

Any cutting and sawing tool must be sharp; not only work efficiency, but also safety depends on this. Forcing too hard with a blunt instrument can cause you to lose control and injure yourself. In addition, the quality of the cut made with a sharp hacksaw will be higher.

To understand how to properly sharpen a hacksaw on wood, let's take a look at the device of a popular tool:

It would seem what is simpler - a steel strip with serrated teeth. However, each structure is developed individually, the shape and location of the cutting elements depend on the type of wood.

Important! The general principle for all types of hacksaws is that the cutting width should be greater than the thickness of the blade.

If you do not follow this rule, the tool will jam in the cut as it goes deeper into the material. This means that at least it is necessary to separate the teeth of the hacksaw. The cutting edge also has features - and this directly depends on the hardness of the wood and the method of cutting.

Hacksaw classification

1. Blade length. The comfort of work depends on this value (you make fewer reciprocating movements), and the teeth on a long hacksaw are not clogged so intensively. As a general rule, the blade for a hacksaw for wood should be twice as long as the size of the workpiece.

1. Tooth size. The speed and quality of the cut depends on this parameter. Moreover, the criteria are mutually exclusive. A hacksaw with a fine tooth gives a high-quality and clean cut, but the speed is lower and more effort is applied. A large tooth saws faster and easier, but the cut edges will be "torn" and rough. In the parameters, the tooth size is indicated in "TPI", the number means the number of edges per inch. The higher the value, the finer the teeth

1. Tooth shape. This parameter determines the direction of the cut (along or across the grain), the type of wood, and the vector of the applied force (from oneself or to oneself). Of course, there are universal canvases. The correct sharpening of the hacksaw is carried out according to the shape of the tooth

Blade steel type. Material classification is a separate topic, we are interested in the processing method. The canvas can be hot, not hot and combined. In the latter case, only the teeth are hardened. This can be determined by the shade of the metal - hardened steel is darker.

Important! Sharpening a hacksaw with hardened teeth is not possible.

This "disadvantage" is compensated by the slow blunting process. If you don't come across a nail or a hard knot, the hardened canvas will last a long time. Truth and the price is appropriate.

Do-it-yourself hacksaw sharpening

Attention! Sharpening a hacksaw begins with setting the teeth.

If the exact parameters are not indicated in the instructions for the canvas, the wiring is done according to the general rules:
The overhang of the cutting edge in width should be 1.5 - 2 of the blade thickness. A wider set is made for wet wood, or in the case of sawing along the grain. If, when processing such wood, the width of the teeth is small, the blade will jam in the cut.

This tool should be in the arsenal of every man, along with a hammer and a screwdriver, regardless of his occupation and carpentry skills. This is an ordinary hacksaw. However, manufacturers have long adapted even an ordinary tool for a variety of purposes - in stores you will come across not only a hacksaw for wood and metal, but also specialized tools for drywall and foam concrete.

Hacksaw for wood - choose the size of the tooth

Even if you already have a hacksaw on your farm, it is quite possible that it will not work for your purposes, so sooner or later you may need to go for a new saw. In choosing this tool, knowledge about its structure and features will come in handy. If the saw has straight teeth, it will be easiest for it to cut the wood across; to cut the wood along the grain, you will need a tool with inclined teeth. In accordance with their inclination, the saw-hacksaw will be transverse or longitudinal. If you do a lot of tinkering, you will need both options.

A hacksaw with large teeth is the fastest to cut, but you won't get a straight cut with it. For gardening or quick cutting of rough boards, this saw is fine. For a cleaner edge of the cut, use a tool with a fine tooth, but working with such a hacksaw is slower - it is more difficult to remove sawdust from the cut.

For sawing coarse wood across the grain, a coarse-tooth saw is best; for normal sawing purposes, choose a medium tooth, and if you need precise work, choose a hacksaw with a fine tooth.

With a very fine tooth, a carpenter's hacksaw is used by professional carpenters; it is hardly useful on the farm. There is also a mechanical hacksaw - this is a small machine with a mechanically movable blade, such are used in industries for sawing metal pipes and other metal elements, in a home workshop it will be replaced by a hacksaw for metal.

Hacksaw saw: tooth pitch and blade length

Tooth pitch is another characteristic that affects the quality and ease of cutting. It is measured in millimeters; this concept is the distance between the tops of adjacent teeth. The length of the saw blade proportionally depends on the size and pitch of the tooth - the larger these parameters, the longer the tool should be. The length of a small hacksaw usually does not exceed 350 mm, the average saw reaches 550 mm, and a tool with a large tooth should be at least 600 mm.

When buying, take an interest in the sharpening of the saw - if we are talking about triple sharpening of the tooth, then it will be convenient to work with it in any arrangement of fibers, both with forward and reverse strokes. In addition, with triple sharpening, such a technique as setting the teeth does not need to be used - the hacksaw will be effective without it.

A hardened saw - what makes this hacksaw so special?

The steel from which the tool blade is made must be elastic and strong. The curvature of the blade when jammed, the rapid bluntness of the teeth indicate a low quality of steel. In order to maintain the sharpness of the tool as long as possible, while not violating the elasticity of the blade, manufacturers resort to a little trick - they only harden the teeth. In this case, they acquire a blue-black color, by which it is very easy to distinguish a hardened tool from a regular one.... These saws are especially useful when cutting plastics such as plywood, plastic, plaster. However, it must be protected from hitting nails, otherwise, having damaged such teeth, it will no longer be possible to restore their former sharpness.

If you still have old father's tools in your workshop at home, you do not need to throw them away, you just need to know some of the features of caring for them. For example, so that the hacksaw blade does not jam when cutting, it is necessary to regularly set the teeth apart and sharpen them.

How to sharpen a hacksaw for wood - step by step

If you are wondering how to make a hacksaw perfectly sharp, do not rush to grab the file - rushing will only aggravate everything. Sharpening teeth is a separate process that has several stages. First, check if you have a suitable tool - when sharpening transverse hacksaws, you cannot do without a triangular file with a fine notch and an angle of 60 °, for a longitudinal tool you need a rhombic file.

How to sharpen a hacksaw for wood - step by step diagram

Step 1: align the teeth in height

To determine which tooth is lagging behind in height, take a smaller file and run it over the teeth from above. Untouched points will indicate to us the defects of the saw. In this case, all other teeth must be filed down to the lowest level. In order not to injure your hands, you can cut a nest for a file in a block of wood, fix it in it and only then boldly level the teeth.

Step 2: sawing through the canvas

Check the prongs for their relationship to each other. Short pieces make it difficult to cut, especially after several sharpenings. In this case, cuts are made in the blade itself, which lengthen the teeth. We clamp the tool blade in a vise, setting the teeth to the same level as the edges of the vise, so as not to allow a cut too deep. You will need a hacksaw for metal - use it to saw through the blade to the desired tooth height. The saw will work best if the width of the teeth is one and a half times smaller than their height.

Step 3: dilute the teeth

It's time to get to the distribution of the saw. If you do the routing with ordinary pliers, then you will never succeed in a uniform, verified spreading to the sides - as a result, the saw will begin to tear the tree, creating a lot of waste and forming a sloppy cut. Therefore, prepare in advance a simple tool that you can make yourself - saw through a groove in a thin metal strip, into which the clove will easily enter, and drill several holes in it to secure the stopper. The limiter can be cut with metal scissors, giving it the desired angle for routing.

We attach the stopper to the bar and test it in practice, increasing or decreasing the bend angle if necessary. With this tool, the layout will be exactly the same. It is not necessary to do it often, once for two or three sharpenings. Obviously, the teeth need to be bred in different directions, observing the sequence. When routing, you should not bend the stick with the distance at which the top of each clove is bent - too small a distance will do nothing, too much will complicate the cutting process and transfer a large amount of material into sawdust.

Step 4: sharpen

Now we come directly to how to sharpen a hacksaw on wood. It is most convenient to fix the canvas on the edge of the desktop by placing a plank under the hacksaw so that the canvas does not rest on the handle. Observe the same sharpening angle as before. First, walk down one side of all the teeth, moving the file away from the hacksaw blade towards the tip, then repeat the process while sharpening the other side. Turning the blade over, in the same order, go over the teeth again with a file.

Be careful not to shorten them by sharpening too hard. In total, the process will take you from half an hour to an hour, depending on how much you have already practiced in this matter. This time will pay off with interest when working with a hacksaw.

You will need pliers, a file, and a little patience to make a hacksaw divorce. The teeth on a hacksaw should be through one in different directions and they need to be sharpened from different sides. You will need pliers to bend each prong in different directions.

The question “how” can be answered in this way: with the help of pliers, with the help of a special adjustable comb, with the help of a chisel, or in any other way.

Why do you need a divorce:

The spreading of the teeth in different directions makes it possible to avoid the saw blade getting stuck in the wood, which partially facilitates the work, but does not always speed up, however, in the case of cutting a thick log, it is much wider than the saw, setting perfectly saves the situation and eliminates those moments when the saw does not the log cannot be reached, because it is jammed there.

Jam the saw maybe due to the fact that iron tends to expand and heat up at the moment of hard work, the expansion makes the progress tough, and the hot metal melts the resin and turns it into a paste, which further slows down the movement of the saw.

To prevent the saw from wedging, it does not stick to the wood, a divorce is made. However, the divorce must be appropriate for the density of the wood. A wide groove is convenient in low density wood, a narrow groove is needed in high density wood.

The divorce is needed in order to provide a wider gap between the saw blade and the wood.

Divorce with pliers is detrimental to the saw teeth, they quickly break off, the bend is not even, the pliers move out often.

The set of teeth with a special comb is convenient for use, does not break the teeth, but the angle of the set is different, the teeth do not stick out to the sides evenly, and this position does not accelerate, but slows down the work, there will be constant jams of the saw blade in the wood. Particularly poorly reflected by the curve of the divorce on dense wood, the saw cannot make a groove, it moves with jerks from one jam to the next. In soft wood, jamming also occurs, but it is easier to pull the saw blade out of the log with a jerk, but when you jerk, you can cut not only the log, but also part of yourself, since the saw breaks out of the groove with a sharp movement and falls out of it without control.

It is best to set the saw with a chisel. It is inserted between the teeth and slowly tapped with a hammer from above, gradually moving along the line of all the teeth. The angle of the chisel is directed in one direction, then in the other, it is necessary to change the direction after each passage of the line of the teeth, and the angle of the retraction of the teeth with the help of the chisel is also changed. This method is suitable for a work saw, where the initial set has already been made and needs to be widened, this option is not suitable on a new saw.

Determine the kerf width according to the formula

Sharpening hand saws

Features of sharpening a hand saw for wood

The most popular tool in woodworking is probably a saw. A hacksaw for wood is used for sawing bars, fiberboard and chipboard, and with a two-handed saw, even a log can be "cut" into dies.

This tool is made of special steel. However, despite the softness of the material (wood) being processed, the hand saw must be sharpened regularly. The main thing is to know how to do it correctly. WITH chainsaw you must also carry out similar procedures.

In the absence of special tools, you can sharpen a hand saw using a triangular or diamond-shaped personal file. If the hacksaw is small, then it can be clamped in a vice, the sharpening of the hand saw for wood is carried out as a result of the forward movement of the file blade.

In this case, you should not put too much effort. It is enough to achieve the appearance of a "fresh" streak on the main posterior surface of the tooth.

Hardened teeth do not need sharpening

In a locksmith's vice, you can also set up a hand saw, because if the teeth are in one line, the cutting process will be impossible. The reason is probable jamming, and the "culprit" here are sawdust, which is not removed from the narrow slot.

If the teeth of the hacksaw are heat-treated (hardened), then the question "how to sharpen the saw" disappears by itself, such a tool is practically eternal and does not require sharpening. It is only important to protect the cutting edges and the teeth themselves from external influences (dynamic impacts). The hardened material, along with hardness, has a disadvantage - it is fragile.

Among professionals and amateurs, the most common hacksaws with a "raw" tooth, so every owner should know how to sharpen a hand saw. To simplify the sharpening process, you can make a simple device from two boards located to each other at a certain angle (optimally 37 degrees).

The hacksaw is attached with two or three planks to the top board. Sharpening itself is performed with a triangular file parallel to the ground, moving "away from you". This is the only way to achieve the correct cutting angle. Turning the saw over, the hand saw is sharpened on the wood from the other side. It is important to achieve the correct geometry of the tooth, ideally it should be an equilateral triangle.

Hand saw tooth setting with plate

In the process of operation, the teeth not only become dull, they also deform. Therefore, the regular setting of the saw on the tree (bending of adjacent teeth in different directions) is a very necessary procedure. The wiring process is carried out using a special plate with a slot, the width of which must correspond to the thickness of the hacksaw blade.

For versatility, you can cut several slots with a grinder. Then you can set a hand saw of any thickness. The hacksaw is clamped in a vice with two strips, a plate with a slot is "strung" onto the tooth. Only the upper part of the tooth is folded back (about one third).

Sharpening hand saws is not difficult in itself; it only takes skill. It is enough to try once. It is not difficult to set up a hand saw. A properly sharpened hacksaw will save you both effort and time when cutting.

Instruments

Wood is a fantastic material, as it can take, after simple manipulations, any form that is limited solely by the human imagination. And just one of the tools that is intended for this business is a hacksaw for wood. It is no less popular than the electric and gasoline chain saws, jigsaws and reciprocating saws known to all of us. There should be such a hacksaw in the arsenal of household tools, and it is useful for every man to know how to sharpen a hacksaw on wood with his own hands.

Purpose of a hacksaw for metal

There are many types and forms of hacksaws for metal. Hacksaws for metal are two-handed and one-handed. Two-handed saws with the advent and spread of gasoline and electric saws are rarely used today, but one-handed saws are found in almost every home.

A single-handed saw blade is made in the form of a knife with many teeth. It is characterized by sufficient rigidity, elasticity and strength to maintain its shape without various tensioning devices. Such a hacksaw for metal has a handle that you can hold with one hand when cutting the material. Moving the saw back and forth on the object being cut, the teeth are inserted deeper into it. For each movement of the hacksaw teeth, the material is cut a few millimeters.

A hacksaw for wood is used for sawing wood, planks, logs, chipboard and other wood materials, when installing wooden structures and joinery, for trimming tree branches and other works that involve cutting different species. A wood saw can also come in handy if you plan to work with laminate flooring.

The teeth of such hacksaw blades are of three types - large, small and medium, they are measured by the number of incisors per inch. The more teeth there are 1 inch, the better the cut will be. The number of teeth per inch on the saw blade for wood is indicated by the TPI mark. Remember that for a quick, rough cut you will need a hacksaw with a long blade and a large tooth. And if the quality of the cut is very important to you, then it is better to take a hacksaw with a fine tooth.

Saws with large teeth (3-6 per inch) and an interdental pitch of about 4-8 millimeters are most useful when sawing logs and thick blocks, and with a hacksaw, in which the interdental distance reaches 3-3.5 millimeters, they cut boards of medium size. When working with small wooden products, it is easiest to work with a saw with a gap between the incisors of 2-2.5 millimeters.

In the event that the hacksaw has straight teeth, the tool will be intended only for cross-cutting wood, but if you have to saw the tree lengthwise, the best option would be a hacksaw with teeth inclined forward. And it is best to have several hacksaws, and not one hacksaw, for different types of woodwork.

The need to sharpen a hacksaw

Any cutting tool will work well under one condition - if it is sharp. A hacksaw is no exception in this case. In a hand saw, the cutting element is the teeth, which are cut on the blade in the form of wedges. During operation, it is these teeth that become dull, that is, the cutting side and front edges are rounded, because of this, the hacksaw stroke becomes heavy, and therefore you need to press it hard.

Sawing with a blunt hacksaw is one torment. You need to spend a lot of time and effort, it is difficult to make a cut at right angles with such a saw. An improperly sharpened saw moves away from the cutting line to the side, it clamps and wedges in the cut. The sharpness of the saw can be determined by the sound of the operation and the brilliance of the cutting edges. To restore the cutting ability of the teeth, they sharpen a hacksaw on wood, giving them sharpness and at the same time maintaining their parameters: the magnitude of the angles, height and pitch.

However, remember that not all hacksaws can be sharpened. Hacksaws with hardened teeth cannot be sharpened. To identify a hardened tooth, you need to look closely at its color. If the tooth is hardened, it has a black color with a characteristic bluish tint. To sharpen non-hardened teeth, a fine-cut file should be used.

Hacksaw tooth setting

Before sharpening a hacksaw for wood, check the tooth setting. For free movement of the saw in the material and avoiding the clamping of the tool in the cut, its teeth are set apart as it deepens, that is, they are alternately bent by the same amount in different directions. As a result, the kerf becomes larger than the thickness of the toothed saw blade, and free gaps appear on both sides.

As a result, the saw will move back and forth, practically not touching the cutting surface with its blade, the cutting edges will gradually begin to remove the material layer by layer. When setting the saw, it should be remembered that the wider the set of teeth, the wider the cut will turn out and, accordingly, the lower the chances of the hacksaw jamming. However, an excessively large set of teeth provokes a too wide ragged cut and requires significant efforts to advance the hacksaw in the wood.

The set value for a hacksaw for wood should be approximately 1.5 to 2 times the thickness of the saw blade, which is usually 1.5 to 2 millimeters. Therefore, it is customary to bend the saw teeth by 0.25-0.5 millimeters in each direction, if such a hacksaw is to saw a dry hard wood, and by about 0.5-1 millimeter for raw wood or soft tree species.

To bend the saw teeth by the same amount, they use a special device called a wiring, which is a metal plate with a slot cut into it, which is wider in width than the thickness of the hacksaw blade. Often, the design of the set allows you to select the amount of set of teeth on one side using an adjusting screw, which ensures the same amount of bend of the teeth.

For setting, as a rule, the saw blade is clamped in a vice in such a way that the teeth protrude from it only slightly, and the device itself is fixed on the desktop. The teeth are bent by setting alternately in opposite directions along the retract line, which is approximately half of their height. Remember not to bend the entire tooth, as this will break it at the base.

After such manipulations, it is recommended to check the correctness of the setting, because it may happen that when bending to the side, some teeth protrude more than others, they will slow down when cutting, reduce the quality of the cut and quickly become dull. Look at the light along the line of the teeth, and if you see that a tooth is too strong or not bent too far to the side, then it needs to be corrected.

Rules for sharpening a hacksaw for wood

Sharpening the saw blade is in a sense an art that requires attention, a good eye and loyalty to the hands. This business is not difficult to learn, the main thing is to adhere to the following rules when working:

Secure fit. The blade should be firmly fixed in a special tool made of wood, which should also be firmly set in a well-lit work area, as shown in the video on sharpening a hacksaw on wood. Sharpening the teeth on your knees or on stools will not work!
Using a quality tool. You should use your personal file with further cleaning of the sharpened edges of the teeth with a file or a file with a fine velvet notch. Of course, the file needs to be sharp and new. You can also use a used one, but it must be brushed with a steel brush and rubbed with charcoal so that the file does not become dull or clogged.
Removing the metal layer. When sharpening a tooth, a file should grip its metal and remove the required layer of metal, depending on the power of pressure. And if it suddenly slips over the tooth without removing the metal, it means that the file is worn out or the teeth of the hacksaw are overheated. In this case, you need to re-sharpen with another file. If, even after changing the file, it slips over the tooth, you should take another hacksaw.
Pressing on the teeth. The file handle is clamped with the right hand, and its end is held with the left hand and the file is guided onto the saw teeth. The file pressure on the teeth should be uniform, smooth and, of course, in one direction. When returning to its original position, the file must not touch the teeth.
Correct file handling. Try to grind the metal from the edges of the teeth of approximately the same thickness, driving the file the same number of times with the same pressure, which allows you to maintain the pitch, height and angle of the teeth after sharpening.
Burr removal. Burrs form on the edges of the hacksaw tooth from the side of the exit, they reduce the sharpness of the teeth, and if you do not remove them, they will crumble during operation of the saw, and after that the teeth become significantly dull. To remove burrs, the edges of the teeth are sharpened with a file with a velvet notch, and also removed from the side edges of the canvas with a wet donkey.
Checking the quality of work. After sharpening the teeth, it is imperative to check their sharpness. Look at the edge of the razor blade and the point of the needle: they don't shine in the light if they are sharp. And if they are dull, then, of course, rounded surfaces appear on the edge of the blade and on the tip of the needle, reflecting light and shining well. Checking the sharpening of the quality of the hacksaw teeth is based on this. For such a purpose, they put it in front of the eyes, examining its teeth along the canvas. If their cutting tips and edges are not shiny, this indicates that the saw teeth are sharpened. And if suddenly some of the teeth shine (this happens often), then they must be sharpened with a file with a velvet notch, that is, remove the burrs and check again the reflection of light over their tops and edges.

DIY hacksaw sharpening

When sharpening a certain type of hacksaw for wood, you should pay attention to some features of this procedure. Let's figure out how to sharpen each type of hacksaw.

Cross Saws

To sharpen the teeth of transverse hacksaws, a triangular file with a rather fine notch and an angle of close to 60 degrees is used. To sharpen the teeth, clamp the hacksaw into a special device that allows its blade to be installed at an angle of 45-50 degrees to the surface of the desktop. Guide the file at an angle of 60-75 degrees to the blade parallel to the work table and in this way sharpen the left edge in the first tooth.

Saw teeth are sharpened in several steps. With a file, first go along the left edges of the odd teeth, which are in the back row, adjusting your hands to the same movements. Then they pass the file along the right edges of the same odd teeth, thereby completing the sharpening of the cutting edges with sharp tops.

After sharpening the odd teeth of your saw blade, turn over the hacksaw blade in the sharpening device to sharpen the even teeth that were in the far row. When sharpening the teeth of cross-cut saws, it is necessary to carefully monitor that sharp cutting edges with an angle of 60-75 degrees are obtained in each tooth, that is, a sharp point and a short cutting edge.

Rip saws

To sharpen the teeth of longitudinal saws with an angle of less than 60 degrees, use files with a coarser or rhombic files with a fine notch, and triangular files with an angle of 60 degrees at the apex are not suitable for sharpening.
To sharpen the teeth of the longitudinal hacksaw blade, it is installed vertically in the clamping device, after which the device is fixed on the working table. Next, we will tell you about two ways of sharpening rip saw teeth, which differ in the size of the sharpening angle.

The first method is straight, when a file or a file at an angle of 90 degrees is directed horizontally to the blade and at the same time a small layer of metal is removed from the back and front edges of the tooth to sharpen the cutting edge. In this way, all the teeth in the far row are sharpened. After that, the blade is turned over in the clamping device and the teeth of the other row that are in the far row are sharpened. Many modern carpenters and hobbyists use this method when sharpening the teeth of such longitudinal hacksaws.

The second method is oblique and it differs from the first only in the direction of the tool itself in relation to the hacksaw blade - the sharpening angle within 80 degrees. Also, the rear and front edges of the teeth are sharpened, for the beginning of one row, and then another. With this method of sharpening the teeth, you will get side edges, which are used when sharpening a bow saw.

Mixed saws

If you decide to buy a mixed sawing hacksaw, you should learn how to sharpen it correctly. To restore the quality of the cutting teeth, sharpen them using coarse-cut needle files or fine-cut rhombic files. As well as when sharpening a longitudinal saw, two methods are known - oblique and straight, and they differ in the magnitude of the sharpening angle (90 and 75-80 degrees).

Tools for sharpening a saw-hacksaw

A hacksaw blade for sharpening teeth is installed in a special clamping device, which is then fixed on the work table. Let's look at the diagram of the clamping device that is used when sharpening the teeth of hacksaws on wood and makes it possible to install them at an angle of the order of 45-90 degrees in relation to your work table.

Such a device consists of a base made of plywood measuring 550 by 200 millimeters and approximately 20 millimeters thick. On the basis, two guiding right-angled triangles (with equal legs) are installed, which are made of a steel strip with a section of 20 × 30 millimeters. To install the guide triangles at the base of the device, 4 pins are provided, which are screwed on with PVA glue.

Further, support and clamping strips are installed to the guide triangles using bolts with wing nuts, which are interconnected by hinges (400 by 150 millimeters in size), made of plywood, the thickness of which is 15 millimeters. For sharpening, the saw is laid with the teeth upward between the slats.

Before you start sharpening a hacksaw on wood yourself, its blade is set in such a way that the teeth protrude above the clamping bar by about 15-20 millimeters. Such a clamping device makes it possible to set the sharpened hacksaws at an angle of 45 degrees and 90 degrees. When sharpening the teeth of mixed and rip saws, set at an angle of 90 degrees, and when sharpening the teeth of transverse tools - at an angle of 45 degrees. If the device is installed in the position of the planks at an angle of 90 degrees, then it is used to level the height of the cloves, as well as for their divorce.

Let's also look at a jig for sharpening large-sized hacksaws and two-handed saws. This device consists of two transverse strips about 550 millimeters long and 40 by 30 millimeters in cross section, two 1100 millimeter long posts and 60 by 40 millimeters in cross section, as well as two clamping bars measuring 450 by 150 millimeters, which are made of plywood 15 millimeters thick. The crossbar and uprights are connected with screws.

The device is assembled in the following sequence: from the floor at a low height, the lower crossbar is screwed to the uprights, then the right leg is placed on it, and after that the attachment point of the second crossbar is marked so that the knee of the right leg rests on the second crossbar.

Because of this, the rigidity of the rack is ensured, which is leaning against a workbench or table. For sharpening a hacksaw for wood, set between the clamping strips, teeth upward and then clamped with bolts with wing nuts. After the end of sharpening on one side, without pulling the saws out of the clamps, the device is turned over and also continues sharpening on the other side.

Now you know how to sharpen a wood saw at home. Follow the directions carefully and adhere to the rules described above, and remember to keep an eye on the hacksaw and determine when it is dull. Be sure to determine what material you will usually work with before sharpening the hacksaw saw, and also carry out the procedure for setting and aligning the teeth of the hacksaw blade.

Sharpening and setting the saw

The main cutting element of any hand saw is a series of teeth that are cut into the blade and are cutters in the form of wedges. Wood, in the manufacture of all kinds of products from it, is sawn along, across and at an angle Θ to its fibers, in this regard, transverse, longitudinal sawing and sawing at an angle to its fibers are distinguished, and in each case, use the appropriate type of saw, which differs from others in shape teeth.

When transverse sawing, transverse saws are used, the cutting edges of the teeth of which, when moving in the wood, cut its fibers like a knife and form a cut. Rip sawing differs from transverse sawing in that the direction of movement of the saw is parallel to the grain of the wood. The leading edges of the rip saws cut the wood like knives in planers, and, going deeper, form a cut. When sawing wood at an angle Θ to its fibers, universal (mixed) saws are used with teeth that are an intermediate form of teeth for transverse and longitudinal saws.

Saw sharpening

Sharpening saw teeth is a kind of art that requires loyalty of hands, a good eye, and attention. It is not difficult to learn this business, you must have the desire and clearly adhere to the following rules:

The saw blade must be firmly fixed in a special device made of wood, which is also firmly set on a well-lit work table. Sharpening saw teeth on stools or on your knees does not give a satisfactory result.
You should use a personal file, followed by cleaning the sharpened edges of the teeth with a velvet (with a fine notch) or file. It is desirable that the file is new, sharp and with a fitted handle. If at the right time there was not one, then you can also use a second-hand one, but it must be brushed with a steel brush and rubbed with charcoal so that the file does not get clogged and does not become dull. When sharpening a tooth, the file should grip its metal and remove its layer depending on the pressure. And if it slides over the tooth without removing the metal, then the saw teeth are overheated or the file is worn out. In this case, it is necessary to repeat the sharpening with a new file. If in this case he slips over the tooth, then it remains to take another saw.
The file handle is clamped with the right hand, and the end of it is held by the left hand and the file is directed to the saw teeth. Working with a file, depending on the type of saw, is described below.
The pressure of the file on the teeth should be smooth and even and only to one side from you. When returning the file to its original position, it must not touch the teeth.
It is necessary to try to grind the metal from the edges of the teeth of at least the same thickness, driving the file the same number of times with the same pressure, which allows you to maintain the angles, pitch and height of the teeth after sharpening.
Burrs form on the edges of the tooth from the side of the file exit, which reduce the sharpness of the tooth, and if they are not removed, then during the operation of the saw they crumble, and the teeth become significantly dull. To remove burrs, the edges of the teeth are sharpened with a file with a velvet notch and deburred from the lateral edges with a wet donkey.
After sharpening the teeth, check their sharpness. Look at the point of the needle and the edge of the razor blade: they are sharp and do not shine in the light. And if they are blunt, then rounded surfaces appear at the tip of the needle and on the edge of the blade, which reflect light and shine well. The quality control of saw teeth sharpening is based on this principle. To do this, put the saw in front of your eyes and examine its teeth along the blade. If their cutting edges and tops are not shiny, then the saw teeth are sharpened satisfactorily, and if some of the teeth are shiny (this is often the case), then they must be sharpened with a velvet-cut file, deburred and again check the light reflection from their edges and tops.

Cross Saws... The teeth of the cross-cut saws are sharpened using a triangular file with a fine notch with an apex angle of 60 °.

To sharpen the teeth, the saw is clamped into a special device that allows its blade to be installed at an angle of 45-50 ° to the plane of the desktop. The file is led parallel to the working table at an angle of 60-75 ° to the saw blade and thus the left edge A 1 A 2 B 2 B 1 is sharpened in the first tooth.

Saw teeth are sharpened in several stages. First, with a file, they pass along the left edges of the odd teeth located in the far row, adjusting the hands to the same movement. Then they pass the file along the right edges of the same odd teeth, completing the sharpening of the main cutting edges with very sharp tops. After finishing the sharpening of the odd teeth, the saw blade in the sharpening device is turned over and thus the even teeth that are in the far row are sharpened. When sharpening the teeth of cross-cut saws, it is necessary to carefully ensure that sharp main cutting edges with a dihedral angle φ = 60-75 °, a short cutting edge and a sharp point are obtained in each tooth.

To sharpen the teeth, the saw blade is installed vertically in a clamping device, which, in turn, is fixed on the work table. Below are two ways of sharpening the teeth of longitudinal saws, differing from each other only in the value of the sharpening angle φ, that is, in the direction of the file in relation to the saw blade.

The first method is straight, in which a file or file is directed horizontally at an angle φ = 90 ° to the saw blade and a small layer of metal is removed from the front and back edges of the tooth, sharpening the cutting edges.

In this way, all the teeth located in the back row are sharpened. Then the saw blade in the clamping device is turned over and the teeth of another row, which are in the far row, are sharpened. This method is used by most modern carpenters and hobbyists when sharpening the teeth of longitudinal saws.

The second method is oblique, which differs from the first only in the direction of the file in relation to the saw blade, that is, the sharpening angle, which is selected within φ = 75-80 °.

Also, the front and rear edges of the teeth are sharpened, first one row, and then another. With this method of sharpening the teeth, side edges are obtained, and it is used by cabinetmakers when sharpening bow swing saws.

Mixed saws... To restore the cutting quality of the teeth, they are sharpened like the teeth of longitudinal saws, using rhombic files with fine or needles with a coarser notch. As with sharpening longitudinal saws, two methods are used: straight and oblique, differing from each other in the value of the sharpening angle φ, which are equal to 90 ° and 75-80 °.

The angle of sharpening φ = 75-80 ° is used by cabinetmakers when sharpening the teeth of spike and fine-toothed bow saws. After sharpening the teeth, remove the burrs from the cutting edges and check the sharpness of the teeth in the light.

Saw sharpeners... To sharpen the teeth, the saw blade is installed in a clamping device, which, in turn, is fixed on the work table. The figure below shows the clamping device used when sharpening the teeth of bow saws and hacksaws and allows them to be set at an angle of 45 ° and 90 ° in relation to the work table.

The device consists of a base with dimensions 550x200 mm, made of plywood with a thickness of about 20 mm. On the base, two guiding right-angled triangles with equal legs, welded from a steel strip with a section of 20x3 mm, are installed. To install the guide triangles at the base of the device, there are four M6 studs screwed on with PVA glue. In turn, to the guide triangles with the help of M6 bolts with wing nuts, the support and clamping strips are attached, connected to each other on hinges with dimensions of 400x150 mm, made of plywood with a thickness of 15 mm. A saw for sharpening is laid between the slats, teeth up. Its blade is set so that the teeth protrude 15-20 mm above the clamping bar. This clamping device allows the saws to be sharpened at 45 ° (shown in the picture) and at 90 °. To do this, it is necessary to change the positions of the guiding triangles on the basis of the device, which is clearly seen in the figure. When sharpening the teeth of crosscut saws, the support-clamping strips are set at an angle of 45 °, and when sharpening the teeth of longitudinal and mixed saws - at an angle of 90 °.

The device in the position of the slats at an angle of 90 ° can be used both for leveling the height of the teeth and for setting them.

The illustration below shows the jig for sharpening the teeth of two-handed saws and large-sized hacksaws.

The device consists of two racks 1100 mm long with a section of 60x40 mm, two transverse strips about 550 mm long with a section of 40x30 mm and two clamping strips with dimensions of 450x150 mm, made of 15 mm thick plywood. The uprights and the crossbar are connected to each other with screws. The assembly of the device is performed in the following sequence: the lower crossbar is screwed to the uprights at a low height from the floor, then the right leg is placed on it and the place of attachment of the second crossbar is marked so that the knee of the right leg rests on the second crossbar. This ensures the rigidity of the stand leaning against the table or workbench. The sharpening saws are placed between the clamping bars, teeth upward and clamped with M8 bolts with wing nuts. Having finished sharpening on one side, without removing the saws from the clamping bars, turn the device over and continue sharpening on the other side.

Saw set

The wider the set of teeth, the wider the cut and, accordingly, the less chance of the saw getting stuck in it. However, too wide a cut due to the large set of teeth requires a lot of effort to advance the saw in the wood.

When using an undiluted or slightly diluted saw, which happens after its repair or long work, when the set of teeth is greatly reduced, the kerf width turns out to be close to the thickness of its blade, and the friction that occurs between the walls of the cut and the blade causes it to heat up and expand and, ultimately account, the saw is jammed in the cut, which will require incredible force to advance. Probably, each of us experienced this trouble when sawing raw wood with a low-diluted saw. And yet, if there is no free clearance in the cut for the saw blade, then it is difficult to control it and it is pulled away from the intended direction.

Saw teeth are set using a special tool called a set. Some of its designs allow you to select the amount of spread on one side using an adjusting screw, which ensures the same deflection of the teeth.

The saw teeth are set in a special wooden clamping device, in which the saw blade is set so that only the teeth protrude slightly from it, and the device itself is attached to the work table. The set of teeth is formed by alternately bending them in different directions along the retract line, which is approximately half of their heights, and the entire tooth cannot be retracted - it will break at the base. It may turn out that when bending, some teeth protrude more to the side than others, and they will slow down during sawing, reduce the quality of the cut surface and quickly become dull. To avoid this, the teeth are aligned by pulling between the jaws of a hand vise, opened by the amount of divorce. As a result, all the teeth are aligned and their setting becomes even.

The amount of saw tooth set apart is determined by the elastic recovery of wood in the cut, which is the greater, the softer and wetter it is. Therefore, for such wood, the divorce should be greater than for hard and dry. The amount of teeth spread on one side and the amount of cut in wood is determined by the formulas:

where a is the thickness of the saw blade (mm), k is a coefficient depending on the state of the wood, k = 0.25-0.4 - for hard and dry and k

Example. Determine the amount of divorce on one side for a bow saw and a hacksaw with blade thicknesses of 0.6 and 0.9. Wood to be sawn: dry and hard for a bow saw and wet for a hacksaw. We choose the coefficient for the bow saw k = 0.35 and k = 0.5 for the hacksaw. Then, for a bow saw, the amount of divorce on one side and the amount of cut are equal:

Δ = 0.35 0.6≈0.2;
b = 0.6 + 2 0.2 = 1 mm;
and, accordingly, for a hacksaw:
Δ = 0.5 0.6 = 0.3;
b = 0.9 + 2 0.3 = 1.5 mm.

You should not choose any amount of divorce for the saw teeth, not taking into account the state of the wood being cut, as this affects the quality of the cut and the effort to advance the saw. It is difficult to cut hard wood with a saw with a large spread value - it turns out a wide, uneven, ragged cut of poor quality, the saw is heavy, you have to put a lot of pressure on it, and as a result, its teeth quickly become dull. Therefore, the master must have in his household several saws with different divorce rates: for dry and wet wood. And if he has one saw with a small divorce and it is necessary to cut damp wood along the fibers, then in the process of sawing a wooden wedge is inserted into the cut, which is advanced behind the saw so that it does not jam, and its surface is additionally lubricated with laundry soap.

Saw setters... The saws are set using a special tool called a setting. The figure shows general views of simple and emphasized routing.

Simple wiring is made in the form of a small steel plate of any shape with a wooden or metal handle. The plate has several slots of different widths.

The use of such a layout is very simple: they choose a slot in the layout that corresponds to the thickness of the saw blade, and, grabbing half of the saw tooth with it, carefully bend it to one side or the other. When bending the teeth, one should strive to ensure that their inclination is the same along the entire length of the saw.

The process of setting saw teeth greatly facilitates the use of a set with a stop, which ensures the same bend of the teeth. Before starting work, the tool is adjusted to a certain amount of divorce, and then the stop is fixed in the desired position with a wing nut and a screw. The saw teeth are set in a wooden (carpentry) and locksmith's vice or in special clamping devices in which the teeth are sharpened. When using a metal vise, plywood strips are laid between their jaws, corresponding to the dimensions of the saw blade. The saw is clamped in a vice so that its teeth are very close to their jaws.

Aligning the teeth in height

Saw tooth shape

Each tooth can be imagined as an acute-angled knife with an apex angle β, sharpened from the sides by one-sided sharpness with a sharpening angle φ = 60-75 ° (sharpening is shaded), and each of them contains two front and two side edges.

For example, in a drawn tooth, the front faces are A 1 B 1 B 2 A 2 and A 1 B 3 B 4 A 2, the side faces are A 1 B 1 B 3 and A 2 B 2 B 4. The edges A 1 B 1 and A 1 B 3 are the main cutting edges, and the edge A 1 A 2, resulting from sharpening the two front edges, is called the short cutting edge. Each tooth, having the above cutting edges, cuts wood when moving in both directions, that is, from itself and towards itself. For example, in a drawn tooth, the cutting edge A 1 B 1 cuts the wood fibers when the saw moves to the left, and the cutting edge A 1 B 3 when the saw moves to the right, and the short cutting edge A 1 A 2 delaminates the cut fibers and removes them in the form of sawdust from the resulting cut.

The teeth of cross-cut saws, which are isosceles triangles, are characterized by a taper angle β, rake angle γ, cutting angle δ, step t and height h. Points A 1, A 4, A 5 are the tops of the teeth. The taper angle β characterizes the saw's ability to cut this or that wood. Usually in cross-saws for soft and damp wood, the β angle is taken equal to 40 °, and for dry and hard wood - 50-60 °. The angles in the triangle of the tooth are between each other depending on:

Rip saws... In longitudinal saws, the teeth are cutters in the form of inclined wedges. The picture below shows two types of teeth, the first is the most common in saws, and the second is with a deep hollow, used in saws for sawing soft tree species (linden, aspen, alder) that generate sawdust abundantly.

The edges A 1 A 2, A 3 A 4 are the main cutting edges, and the edges A 1 B 1, A 2 B 2, A 3 B 3, A 4 B 4 are the side cutting edges. The teeth in longitudinal saws, like cutters on planing machines, cut wood when moving only in the direction of the inclination of the teeth, in which the main cutting edges, performing cutting, form the bottom of the cut, and the side edges form its walls, and when they move backwards, they make an idle motion, sliding along the cut and not cutting wood.

The positions of the cutting edges of the tooth form angles between themselves: α - the back angle formed between the back face and the cutting plane; β is the angle of sharpening between the front and rear edges; γ is the rake angle between the front face and the perpendicular to the cutting plane; δ - cutting angle; π is the angle between the front and back faces of adjacent teeth. Considering the triangle of the rip saw tooth, we find the relationship between the angles:

α + β + γ = 90 °; α + β = δ; π

The quality of the cut surface and the performance of the sawing process depend on the correct choice of the angular values of the cutting tooth of the saw. The most important of all angles is the angle of sharpening β, with a small value of it, sawing wood occurs with less effort, but the strength of the tooth decreases, it crumbles, quickly becomes dull, and has to be sharpened frequently. With a large value of this angle, the strength of the tooth increases, but the cutting force increases. Typically, the taper angle should be at least 20 °.

With an increase in the cutting angle δ, the quality of the cutting surface increases, but the cutting force increases, the cutting angle can be reduced due to the clearance angle, but at the same time the friction between the tooth and the wood increases and the tooth heats up excessively, is released, and its strength decreases, therefore the cutting angle δ is taken within 40-75 °.

Angle γ determines the inclination of the tooth, its value is taken in the range of 10-20 °.

Thus, the values of the angles α, β, γ for the teeth of longitudinal saws are interrelated, and they are determined by practice - for example, the teeth of bow longitudinal (swinging) saws are determined by the angles α = 20-30 °, β = 50-60 °, γ = 8- 10 °, and the teeth of the hacksaws of longitudinal sawing - with angles α = 20-40 °, β = 40-50 °, γ = 10-20 °.

Mixed saws... In hand saws, tooth designs are widely used, which can be used for both longitudinal and transverse sawing of wood. The illustration below shows some of the tooth shapes used in mixed saws.

If the teeth of longitudinal saws can be characterized as acute-angled wedges, then the teeth of saws for mixed sawing can be represented as rectangular or obtuse-angled wedges with a cutting angle δ = 90 ° + γ. Angle γ - front, equal to zero or a negative value in the range of 10-15 °. They cut wood with these saws in the same way as longitudinal ones, when moving only from themselves, and when moving towards themselves, they idle.

The edges A 1 A 2, A 3 A 4 are the main cutting edges, and the edges A 1 B 1, A 2 B 2, A 3 B 3, A 4 B 4 are the side cutting edges. When sawing wood along the fibers, the main cutting edges form the bottom of the cut, and the side edges form its wall, and when sawing wood across the fibers, the side edges A 2 B 2, A 3 B 3, A 6 B 6 are cut from the sides of the cut wood fibers, and the main cutting edges A 1 A 2, A 3 A 4 delaminate the cut fibers and remove them in the form of sawdust from the cut.

The saw teeth for mixed sawing are defined by the taper angle β, the cutting angle δ and the rake angle γ. The angles δ and γ are related by the dependence δ = 90 ° + γ. The quality of the cut surface and the performance of the sawing process depend on the correct choice of the angular values of the teeth. In practice, the following angles are chosen: in bow saws β = 60 °, γ = -10 °, hacksaws β = 45-50 °, γ = 0 ° or - (10-15 °). Saws with teeth with a rake angle γ = -10 ° are widely used in bow saws (tenon, fillet) as universal for sawing wood in any direction.