Do-it-yourself knife from a saw for metal: manufacturing features. Kitchen knife from a disk from a circular saw Knife from a circular saw for wood

Want to create a unique knife? Do you need a wood chisel or a sharp blade for hunting? Making a good product with your own hands is more than real. The main thing is to have the skill of working with metal and know what you want.

Making a knife: where to start?

First, prepare all the necessary parts and tools, put them in one place. Decide which material you will be using. If you need a sharp and durable product - make a knife from a saw.

Take the workpiece. A saw blade for wood or metal is best suited for this purpose. As a material for the manufacture of the handle for the blade, use wood (any, according to your desire), textolite, plexiglass.

What tools will be needed in the process of making a knife?

To get started and make a knife from a saw for metal, you will need:

file;
electric drill;
marker;
ruler;
sandpaper;
paste for polishing surfaces;
copper or aluminum for rivets.

How to make a preparation?

Let's figure out how to make a knife from a saw. Prepare the metal sheet for making the blade. Draw on it the blank of the future tool, using a marker for this purpose.

Remember that a knife is considered a melee weapon if the length of the blade exceeds 2/3 of the total length of the product. If you design a knife from a saw incorrectly and it is regarded as a cold weapon, expect punishment.

Having outlined the contour of the future product, take on the undercut form. It is important to draw the shape so that the cutting part of the future product is located in the area of the saw teeth. Due to the saw setting, if you make a butt in this place, you will have to do additional work to grind the bulge.

Things to Consider Before Getting Started

Do not start grinding a knife without practicing. Take an ordinary piece of metal and try to process it. Spoiling a piece of iron is not as scary as losing a good workpiece. You must not only regulate the pressing force when turning, but also monitor the temperature so as not to overheat the iron. High temperature not only spoils the appearance of the metal. Even if outwardly it does not change, then its structure can be seriously affected: the metal will become much softer and more brittle. A knife made of low-quality metal will have to be sharpened more often.

To check if the iron has begun to overheat, put a couple of drops of water on the workpiece. If it immediately evaporates, rather cool the workpiece for the future blade. To avoid possible troubles associated with overheating of the metal, place a container of water near the machine and periodically cool the future knife from the saw.

Work with a workpiece

Having formed the basis of the future knife, proceed to the most important and difficult stage of work - the removal of descents. The descent is the surface on the knife, gradually tapering towards the blade. The purpose of the knife directly determines the angle and width of the slopes. Therefore, choose the average value if you want to get out of the saw.

Before starting work on the machine, draw the intended slopes on the metal sheet using a marker. Grind carefully, slowly, so as not to spoil the future knife. It is recommended, as in the previous step, to practice on a spare part. The slopes must be symmetrical and lie at the same angle on both sides. In this case, the blade should be undersharpened: leave an indent of about 0.25 mm.

To hone the blade, use. For such purposes, sandpaper of 8-10 hardness numbers is best suited. It is better to sharpen a knife from a saw for metal on a wooden block. To prepare a makeshift sharpener, take a bar and glue sandpaper to it.

Using a large sandpaper, you will give the blade the necessary sharpness, and taking a finer one, you will sand the metal blade completely.

At the final stage of processing, polish the blade. Cover the same wooden block with felt or leather, rub and polish until you achieve the desired effect.

How to make a knife handle

The easiest way is to glue the handle from two cut and prepared pieces of wood or plexiglass. It is much easier to make it than to fix it on the tail of a knife. Naturally, you can choose a simple option and tape the handle with tape, but why try so hard to end up spoiling the aesthetic appearance of the knife?

And here comes the most important stage of work. Since you will have to drill in the shank of the knife, the blade can easily burst. Therefore, be vigilant and careful.

Steel is a hard, but at the same time brittle material. With a uniform distribution of pressure, when the saw is in operation, it is almost impossible to break it. But with spot drilling, the pressure builds up and the metal can easily crack. Therefore, it is better to drill a hole at low machine speeds and do not forget to add oil to the drilling site. In this case, a screwdriver is an ideal tool for fulfilling the goal, since it has less revolutions, then the possibility of part breakage is not so high.

Having completed the previous step and having made holes in the handle, drill the same holes in the halves of the handle. Make a copper or aluminum rivet. For insurance, you can glue the area where the rivet will be with glue, but it is better if you have epoxy.

Can the process be simplified?

Masters say that the hole can be made without the use of drilling tools. The blade together with the shank is covered with a layer of varnish. Where there should be a hole, you need to clean the surface of the varnish. It is necessary to place a knife from a saw on a tree into an electrolyte solution and lower a wire with a negative charge into the container with the workpiece, and connect the positive wire to a power source, which can be used as an ordinary battery.

As a result of such an impact, a hole will be obtained in the metal, however, it will not be perfectly round, but it will definitely not work to damage the blade in this way.

Other Part Processing Methods

If for some reason you can’t make a knife out of you, no required material- replace it. For the manufacture of the blade, an automobile spring is well suited, the metal of which is softer than that of a saw. To process such a workpiece, you do not have to use a sharpener, but you will need a metal saw to cut the shape of the blade. Since metal is easier to process, the edges of the workpiece can be adjusted with a file. It will take longer to work on making a knife in this way, because each stage of processing includes manual work.

Making a knife from a saw is a laborious process, but the result is worth it. Having made a knife from a saw with your own hands, you will get a high-quality and unique blade.

Having made a knife from a saw with your own hands, you can get at your disposal cutting attachment, which one performance characteristics Much better than factory counterparts. Making a knife with your own hands, it is given exactly the shape that most suits the master. Factory knives are beautiful, but not always reliable. There is no guarantee that they will not let you down at the most crucial moment.

A homemade knife from a disk, a hacksaw for wood or a saw for metal will last for many years, regardless of storage and use conditions. Consider how to make a knife from factory-made metal parts, what you need for this and what you should pay special attention to.

Raw materials for manufacturing homemade knife can be any new or old hardened steel cutting piece. As a workpiece, it is better to use cutting discs for metal, blades of hand and pendulum saws. A good option is an old chainsaw. A blade can be forged and turned from its chain, according to its quality and appearance not inferior to the famous Damascus steel.

In order to make a knife with your own hands, you will need the following equipment and materials:

Bulgarian;
grinder;
electric drill;
ruler;
hammer;
sandpaper;
sharpening bars;
files;
core;
epoxy adhesive;
copper wire;
marker;
bucket with water.

Separately, you need to think about the issue with the handle. The finished product should fit comfortably in your hand.

To make a pen, it is better to use:

non-ferrous metal (copper, bronze, brass, silver);
tree (oak, alder, birch);
organic glass (plexiglass, polycarbonate).

The raw materials for the handle must be intact, without traces of cracks, rot or other defects.

Rules for working with metal

In order for the blade to be strong and resilient, in the process of its manufacture it is necessary to follow the rules for working with metal. They are as follows:

Blanks must not have visible or hidden damage. Before making a knife, the blanks must be inspected and tapped. A solid part sounds loud, and a defective one is muffled.
When designing the shape of the blade, corners must be avoided. In such places, steel can break. All transitions should be smooth, without kinks. The cuts of the butt, the handle and the fuse must be ground off at a right angle.
When sawing and sharpening, do not overheat the steel. This leads to a decrease in its strength. An overheated blade becomes brittle or soft. During processing, the workpiece must be constantly cooled by completely immersing it in a bucket of cold water.
When making a knife from a saw blade, you need to remember that this product has already gone through a hardening cycle. Factory saws are adapted to work with the hardest alloys. If you do not overheat the canvas in the process of turning and finishing, then it will not have to be hardened.

The blade shank must not be made too thin. It is on this part of the product that the greatest load will fall.

Making a knife from canvas

If the canvas is large and does not have much wear, then several blades can be made from it. for various purposes. The time and effort spent is worth it.

Knife from circular saw do it yourself in the following sequence:

A pattern is applied to the canvas, the contours of the blade are outlined. Scratches or dotted lines are applied over the marker with a core. So the pattern will not be erased when cutting the workpiece and fitting it to the desired shape.
Workpieces are cut from the circular saw blade. To do this, it is better to use a grinder with a disc for metal. Leave a margin of 2 mm from the contour. This is necessary in order to remove the material burned by the grinder. If there is no grinder at hand, then you can grind the workpiece with a vice, a hammer and a chisel or a hacksaw.
On the grinder all excess is shaved off. This process will take a lot of time so as not to overheat the steel. To prevent this, the workpiece must be regularly lowered into water until it cools completely.
The blade is outlined. Here you need to be careful to keep the contour of the knife, do not burn it and maintain an angle of 20º.
All straight sections are aligned. It is convenient to do this by applying the workpiece to the side of the grinding wheel. Transitions are given a rounded shape.
The part is cleared of burrs. Blade grinding and polishing. For this, several interchangeable circles on a grinding machine are used.

Separately, we should dwell on how the handle is made. If wood is used, then a monolithic fragment is taken, in which a longitudinal cut is made and through holes. After that, the blank is mounted on the blade, holes for fasteners are marked in it. The handle is fixed on the blade with rivets or bolts with nuts. In the case of a bolted connection, the caps of the hardware are sunk into the wood and filled with epoxy glue.

When the handle is assembled from plastic, 2 overlays are used, which must be symmetrical. To give the knife originality, plastic linings are painted with inside. In the overlays, you can make cavities filled with jewelry, products made of non-ferrous and precious metals, small compasses and photographs.

After fixing on the blade, the handles are turned until they acquire the necessary shape and smoothness.

chainsaw knife

Saw chains are made of high-quality alloy, which perfectly tolerates long-term friction and high temperature. The process of making a blade is long and laborious, but the result is a beautiful, unique and very durable knife. To work, you need a heavy anvil, barbecue and charcoal. To make it easier to handle a hot workpiece, you need to purchase blacksmith tongs.

The manufacture of a blade from a chain from a chainsaw must be carried out in the following sequence:

Prepare clothing and gloves made of thick fabric and a protective mask. Pour charcoal into the hearth and set it on fire with a special liquid.
Fold the workpiece from a single piece of chain. In the place where the handle will be, you can add a few segments from the chain. It should be remembered that the result of the work should be a single monolithic product. Separately, the handle for the knife is not made.
Put the workpiece on the coals. Provide air flow to raise the temperature. Wait until the steel turns dark red. In this state, it becomes forged without losing its quality characteristics.
Remove the red-hot chain from the fire and place it on the anvil. With a few strong blows, flatten it so that the links fuse together, turning into a single monolithic part.
Step by step, heating the workpiece in the furnace and giving it the desired shape with a hammer, forge a knife with a handle and blade indicated. After cooling the workpiece, sharpen and polish it.
Carry out hardening of the product. To do this, it must again be red-hot and lowered into cold water. After that, you can finish the knife. For this, acid and an engraving machine are used. The finished blade is polished again and washed in warm soapy water.

At self-manufacturing the blade must adhere to certain parameters in order to ready product did not fall under the category of edged weapons.

How to make a knife from a saw with your own hands

Making a knife out of a saw do it yourself, you can get a cutting device at your disposal, the characteristics of which are much better than factory counterparts. Making a knife do it yourself, he is given exactly the form that best suits the owner. Factory knives are beautiful, but not always reliable. There is no guarantee that they will not fail at the crucial moment.

Homemade knife with disk, wood saw or metal saw will last for many years, regardless of storage and use conditions. Think about how to make a knife from factory-made metal parts, what is needed for this and what you need to pay special attention to.

Tools and materials

The raw material for making a homemade knife can be any new or old cutting part made of hardened steel. As a workpiece, it is better to use metal cutting blades, manual and pendulum saw blades. good option is an old chainsaw. From your chain, you can forge and cut a blade in quality and appearance that is not inferior to the famous Damascus steel.

To make a knife with your own hands, you will need the following equipment and materials:

Bulgarian;
meat grinders;
electric drill;
ruler;
hammer;
sandpaper;
grinding rods;
files;
core;
epoxy adhesive;
copper wire;
marker;
bucket with water.

Separately, you need to think about the handle. The finished product should fit comfortably in your hand.

Rules for working with metal

In order for the blade to be strong and elastic, in the process of its manufacture it is necessary to follow the rules for working with metal. They are as follows:

Blanks should not have visible and hidden damage. Before you make a knife, you need to check and seal the gaps. The solid part sounds sonorous, and the defective part sounds boring.
Corners must be avoided when designing the blade shape. In such places, steel can break. All transitions should be smooth, without kinks. The splice, handle and fuse sections must be grounded at right angles.
When cutting and honing, the steel cannot be overheated. This leads to a decrease in its strength. An overheated blade becomes brittle or soft. During processing, the workpiece must be constantly cooled by completely immersing it in a bucket of cold water.
When making a knife from a saw blade, remember that this product has already gone through a hardening cycle. Factory saws are adapted to work with the hardest alloys. If you don't overheat the canvas during the turn and finish, you don't need to soften it.

Knife from circular do-it-yourself saws "Tiger"

How to make a knife out of disk saws

The blade shank cannot be too thin. It is on this part of the product that the greatest load will be.

Making a knife from canvas

chainsaw knife

Saw chains are made of a high quality alloy that can withstand long-term friction and high temperatures. The process of making a blade is long and lengthy, but the result is a beautiful, unique and very durable knife. The work requires a heavy anvil, barbecue and charcoal. To simplify the processing of a hot part, you need to buy blacksmith tongs.

Making a blade from a chainsaw should be done in the following order:

Prepare clothes and mittens made of thick fabric and a protective mask. Fill the coal in the hearth and set it on fire with a special liquid.
Fold the workpiece from a single chain. In the place where the handle will be, you can add a few parts from the chain. It should be remembered that the result of the work should be one monolithic product. Separately, the handle for the knife is not produced.
Place the workpiece on the coals. Provide air supply to raise the temperature. Wait for the steel to turn dark red. In this state, it becomes fake without losing quality characteristics.
Take the red-hot chain out of the fire and place it on the anvil. A few hard hits to flatten it so that the joints fuse together, becoming a single monolithic piece.
Step by step, heating the workpiece in the oven and giving it the desired hammer shape, forge a knife pointing to the handle and blade. After cooling the workpiece, grind and polish it.
Do product hardening. To do this, it must again become red-hot and lowered into cold water. After that you can finish the knife. For this, acid and an engraving machine are used. The finished blade is polished again and washed in warm soapy water.

I decided to write an article on how to make a knife. The main idea is that all work will be done by hand (with the exception of drilling and heat treatment). The idea came about because there are a lot of articles that say that to make a knife, it is enough to have on hand a few files and a drill, or something like that. I was interested to know how long the whole process would take, and whether I would have to cheat and use power tools. Creating a knife in this way was a wonderful experience. The whole job took much longer than I expected. And at the end, I was imbued with a new respect for people who make knives by hand. In general, I am pleased with the result, and I hope that this article will help anyone who wants to try to make a knife with their own hands.

Creating a knife layout

I tried to make the knife as large as possible, using a design whose contours fit the dimensions of the disk as closely as possible. Thanks to the model of the knife, made by me from thick paper, it was easy for me to transfer its outlines to the surface. For this procedure, I used a marker with a thin rod. It may seem like a small thing, but I think this detail is important. Compared to a regular marker, the thin one leaves a more precise line. If the line is too thick, then when cutting the workpiece, you can make a mistake.

Cutting a workpiece

After securing the disc to my workbench, I started cutting out the approximate shape of the blade using straight cuts. If you have never used a hacksaw, make sure the blade is properly secured with the teeth pointing forward. The hacksaw should cut when pressed "away from you".

Sawing out bends

In order to cut out the curved section of the handle, for convenience, I had to make several perpendicular short cuts along the entire bend. Then, working with a hacksaw at a slight angle, I cut each piece. Short cuts make it much easier to cut the curves.

Primary file processing

To improve the shape of the workpiece, I attached a block of wood to the desktop and fixed the blade on it with the help of clamps. This made it possible to process the edges with a file. At the same time, the blade was conveniently and securely fixed. I also used the file to identify areas that need more work. The design called for a slight bend in the butt, and I applied the flat part of the file to check the progress of the work on this bend. If there was a flat area on the butt, it could be easily found with a file.

Giving the workpiece its final shape

I used several types of files to get as close as possible to the shape drawn by the marker. At this stage, the workpiece began to look more like a knife and it was already more difficult for the eye to detect flaws. If there was a place to work on, I corrected the outline with a marker and then processed the workpiece to a new line. This line was necessary so as not to overdo it and not ruin the design. The last photo shows the blade after shaping it with a file and sandpaper. I don't have a photo of how I grind the blade. At this stage, the traces left by the file were removed. I started with P150 grain and worked my way up to P220.

Shank drilling

I originally planned to make a sharp edge with a high cutting edge, but I did not want to test my limited abilities. The saw blade is made of a fairly thin material, and I would not be able to file a sharpening edge with a cutting edge with a file, which I wanted. We will return to this topic later. At this stage, I measured the location of the rivets, applied cores and drilled holes with a cordless drill.

Preparing to work with a cutting edge

I applied paint with a marker along the future cutting edge of the blade. Then, using a drill the same thickness as the blade, I scratched a mark exactly in the middle of the blade line. This line is hard to see in the last image, but it's there. This mark will be convenient when filing the cutting edge with a file, so as not to make it with an uneven slope.

Formation of the cutting edge

To form the cutting edge, I used a file with coarse notch, at this point I realized that I did not have sufficient skills to manually grind the sharpening edge. So I opted for a smoother angle, filed from the edge to the butt. I'm new to this, so I opted for a more conservative method of stock removal. After the cutting edge was properly ground, I went over the entire blade with P220 grit sandpaper.

finished blade

Here is the blade after shaping, filing, sanding. Ready for heat treatment.

hardening

Before proceeding, I would like to point out that heat treatment can also be done over an open wood fire, but I wouldn't recommend it. The thing is that this method seems unsafe to me. So I used my mini-forge. If you don't have anything like that, in fact, you can use third-party services to heat treat the blade. There are some enterprises that are ready to perform heat treatment. For money, of course. Let me explain how I did it. He made a fire with the help of wood raw materials. For bellows, I used a hair dryer attached to a pipe. I turned on the hair dryer and heated the coal to red. It didn't take long. I placed the blade in a fire and heated it until it was no longer magnetic. Then I tempered it in a container of peanut butter. The last photo shows what the blade looks like after hardening. Although it is possible to conduct heat treatment on an open fire, I do not recommend it.

Vacation

Then it was time to spend the vacation of the blade. First, I cleaned with sandpaper the scale that remained after hardening. I set the temperature in my oven to 190 degrees Celsius and put the blade in it for 1 hour. An hour later, I turned off the oven and left the knife in it to cool to room temperature without opening the oven door. You can observe a light or bronze tint that the blade acquires after tempering. After this procedure, I sanded the blade with P220 grit sandpaper and then switched to P400. In the last photo, I am using P400 sandpaper wrapped around the bar. Processing is carried out from the shank to the tip in only one direction. This treatment makes the surface uniform.

Cutting out the handle

Using the blade as a reference, I drew the outline of the hilt on the block of wood. The handle will be walnut. Here again I used a bar and clamps, and cut two pieces 0.6 centimeters thick each. In a state of excitement, I hastened to cut the tree. Wait a bit to think about the course of action, and I could do it with less effort, and probably with better results. My first mistake was cutting off the excess part. It can be used for clamping while cutting. Here my inexperience showed up, and, as a result, more work was done. Although, in the end, they managed to make two parts suitable for the handle.

Preparing the handle for gluing

So that the handles fit well on the shank after gluing epoxy resin, using a flat surface and sandpaper, I made one side of each of the parts as flat as possible. So there will definitely be no gaps after gluing. At this point, I also decided on the shape of the handle, and in order to finally make sure of this, I applied its approximate outlines. Then I again transferred the outlines of the shank to wooden part handles. Sawed out with a jigsaw approximate form on one of the parts, and then, attaching it to the other, transferred the contour to the second. This operation gave me the opportunity to make approximately the same parts, which will be convenient when gluing. The last photo shows a fitting to check that all parts of the shank are covered with wood.

Formation of the upper part of the handle

Once again it's time to work with sandpaper and give a more precise shape. At this stage, it is important to finalize the shape for the fitting or the upper part of the handle, because after gluing, it will be more difficult to process. And also processing these parts after gluing, you can scratch the blade. Therefore, I achieved the final shaping and finishing of this part with P800 sandpaper.

Preparation of holes for rivets

Having drilled one hole in the wood for the rivets, I inserted a drill of a suitable diameter into it to fix this axis. In other words, this was done for fixation in order to avoid mistakes when drilling the second hole. I drilled the other side of the handle in the same way, making sure that the corresponding holes line up.

Making staves

As a rivet, I used a stainless steel rod with a diameter of 4.7 millimeters. Before applying a layer of glue, I treated the surfaces to be glued with acetone or alcohol to remove dirt, dust or oil.

The first cutting tools made by man were made of stone. The ancestors of modern knives were very fragile and required a lot of time and labor to manufacture. The metal blade is devoid of these major drawbacks. The steel is relatively easy to process and has good physical characteristics.

A handmade knife is the pride of the owner. In self-manufacturing, those characteristics that are necessary are selected. First of all, it is the shape of the blade and handle. The highest quality blades, such as damask or Damascus steel, are made by forging. The blade material at the same time has the necessary hardness and carbon content.

But forging requires a certain tool and skills. What to do if you want to make your own, unique blade, but only a minimal set of tools is at hand? In this case, you should pay attention to the circular saw as a blank for the blade. The metal from which the canvas is made circular saw lends itself well to hardening and has the necessary elasticity, so the saw will be the best workpiece for making a knife with your own hands. A homemade knife from a circular saw holds sharpening well, does not break and can easily compete with industrial knives.

Creating a knife layout

The first step is to create a layout of the future knife from the saw. At this stage of work, you can decide on the shape of the blade of the future blade and the shape of the handle. The layout is best made from thick cardboard or thin plywood. You can also use thick plastic. A rigid pattern will allow you to understand how the knife from the circular saw will lie in your hand and how convenient it will be to use.

When making a layout, it is important to adhere to the following rules:

Right angles must be avoided. A right angle is a place of stress concentration. The knife blade most often breaks or cracks in this place.
The shape of the blade must be chosen based on the purpose of the future knife. The most versatile forms with a straight or lowering butt. Such a blade is equally good at both cutting and stabbing.
The dimensions of the layout must match the size of the saw blade.

When making a layout, it should also be remembered that a knife can be classified as a melee weapon. It all depends on the shape and size. The manufacture and possession of edged weapons is a criminal offense. Therefore, in order not to fall under the article of the criminal code, it is necessary to create a layout that meets the following rules:

The length of the blade or cutting part should not exceed 9 centimeters. Exceeding this length even by 1 mm will make it possible to classify a homemade blade as a melee weapon.
A knife with a blade thickness of more than 2.6 mm is also a melee weapon. This parameter can be neglected, since the thickness of the saw blade is usually 2 mm.
Hardness should not be more than 42 units. This parameter refers to hardening, so we also skip it at the stage of making the pattern.
The handle must have a limiter protruding beyond its limits by no more than half a centimeter. If there is no limiter, then the subdigital recess should be less than 4 mm deep.

After the layout that satisfies the letter of the law and personal preferences is drawn, you can proceed to transfer the layout to the saw blade. The pattern is applied to the saw blade and outlined with a marker. It is best to use a thin marker. A thin line will allow you to more accurately cut the workpiece and avoid unnecessary processing of the workpiece with a file.

Cutting and pre-processing of the workpiece

Sawing the workpiece is fastest with a grinder with a thin cutting disc for metal. If it is not possible to use the grinder, then you can use hand saw for metal. It is important to correctly install the file in the hacksaw. The teeth of the file should be directed forward and the hacksaw should cut when moving “away from you”.

First, with the help of straight cuts, the approximate shape of the knife is cut out. Then cut out the folds. They are easiest to cut with several oblique cuts converging at one point. It is important to leave an allowance of 2-3 millimeters to the drawn contour. This is due to the fact that when using a grinder, the metal at the cutting site overheats. Grinding 2–3 mm with a file and sandpaper can remove the overheated edge of the metal.

Giving the workpiece its final shape

A rough workpiece is brought to its final shape with a file or emery. In order to avoid overheating of the future knife from the saw, when processing it with emery, it is necessary to periodically lower it into a container of water. This will allow the workpiece to cool. When processing the workpiece with a file, additional cooling is not required. It would be most optimal to approximately process the workpiece on emery, and then fine-tune it with a file.

During finishing, special attention should be paid to the smoothness of the folds. It is important to ensure that the bend is even, without depressions or bulges. Miniature depressions are easy to check with a file. To do this, using a marker, the checked end of the workpiece is painted over. Next, carry out a file with light pressure along the workpiece along the entire bend. In those places where the trace of the marker remains, there are depressions.

Processing continues until the moment when there is not a single depression left.

Next, the workpiece is cleaned of burrs and polished with sandpaper. You can start with 60 grit and finish at 320 enough. The workpiece will still be subjected to heat treatment, so the final grinding of the blade will be later.

Shank drilling

The handle on the shank can be fixed with rivets or with glue. Most reliable option fastening the handle is to use rivets. To install them, you need to make holes in the shank. The holes are marked on the shank so that they are approximately in the middle of the future handle. In order to prevent the drill from slipping at the initial stage of drilling, holes are punched.

Due to the fact that the circular saw is made of alloyed tool steel, it will not be so easy to drill it. Ordinary metal drills won't last long here.

Drilling should be done with cobalt drill bits or a ceramic drill bit with a pobedit tip.

During the drilling process, it is important to add oil to the drilling area and not allow the drill to overheat.

Drilling hardened steel is quite a difficult task. Therefore, it is possible to make holes in the shank electrochemically. To do this, attach a wire to the workpiece, then completely cover the shank bituminous mastic or plasticine. In places of future holes protective layer scratched down to bare metal. Next, a saturated solution of sodium chloride is prepared, into which the blade shank with a wire and an unnecessary metal plate are also lowered with a wire. Both wires connect to the battery or car charger. “Plus” is applied to the future knife from the circular saw, “minus” to the plate. The etching process is accompanied by gas evolution. After 30-50 minutes, the holes will be ready.

Formation of the cutting edge

Before proceeding with the formation of the cutting edge, it is necessary to carry out preparatory work. It consists in drawing markings on the edge of the workpiece. The markings are placed exactly in the center and serve as a guide for making a symmetrical descent.

To do this, the edge is painted over with a marker, which will be cutting, and using a drill equal in thickness to the workpiece, the markup is scratched. The drill has a conical sharpening. Therefore, if you place the drill and the workpiece on the same plane, the tip of the drill will be exactly in the middle.

Then, using a file with a large notch, you can begin to form the cutting edge. In the absence of the proper skill to create a smooth edge, you can use simple fixture. It consists of a base, a corner and a guide with a platform for sandpaper. Sandpaper with a grit of 180 is glued onto the guide pad. Several holes must be pre-drilled vertically one above the other in the corner. The knife is fixed flat on the base and the guide is inserted into the hole at the height so that the angle between the base plane and the platform with sandpaper is the one chosen for the formation of slopes. An angle from 22 to 30 degrees is universal.

Having made a smooth descent to the middle of the thickness of the workpiece, the knife is turned over, then the same descent is made on reverse side. Using such a simple device, you can easily form an even blade.

Thus, a finished blade with a given sharpening angle is obtained. But at this stage, the blade is only conditionally ready. It does not have the necessary hardening in order to confidently keep sharpening. Also, it has not been tempered to reduce brittleness. In fact, this is a semi-finished saw knife that can already be used, but it is better to take a few more steps.

hardening

Heat treatment will give the knife the necessary hardness, it will not become dull during operation.

For hardening, a saw blade must be heated to a temperature of 750–920 degrees. If you do not reach such a temperature, then the steel will not be hardened, and if you heat it too much, the blade will be too brittle.

At home, it is not possible to determine the exact temperature. However, there is a way out. A simple magnet will do to control the temperature. As soon as the blank for the blade ceases to be magnetized, it is heated to the desired temperature.

After the temperature of the workpiece has reached the desired limits, it must be kept in this state for about 1-1.5 minutes for every 1 mm of thickness. In the case of a homemade saw blade, the holding time for hardening is 3-5 minutes. This will be enough. Further, the workpiece is lowered into vegetable or machine oil preheated to 50 degrees. This procedure must be carried out carefully. Oil fumes can flare up from a hot workpiece, so keep a fire extinguisher handy.

A little about the forge for hardening. If you use industrial equipment is not possible, then the bugle can be made by hand. To do this, it is necessary to build a fire of such dimensions that it is possible to evenly heat the workpiece. Further, as the firewood burns out and coals appear, a homemade knife is placed on them. As bellows, you can use a household hair dryer or a mattress pump.

Vacation

After hardening, the blade must be released. This procedure is carried out in order to reduce brittleness, as well as to give the saw blade high elasticity. For tempering, the blade is cleaned with sandpaper from the scale formed during the hardening process, and placed in a conventional oven heated to 190 degrees. There the blade is aged for an hour, then the heating of the oven is turned off.

The knife should cool down smoothly to room temperature.

After this procedure, the workpiece has the necessary hardness and elasticity.

Sawing the handle blank and preparing for gluing

To complete the work with the knife, you need to make a handle. There can be various variations of materials used as a handle. The most popular material is wood. The wooden handle is impregnated linseed oil to prevent the harmful effects of moisture on it.

A flat plank is selected from a tree of the species you like. The thickness of the plank should be at least half a centimeter for convenience. A thick plank can be sawn lengthwise. Using the knife blank as a template, markings are applied to the board, including holes for rivets. For a good fit of the future handle to the shank, it is necessary to remove the fit plane with sandpaper.

Formation of the upper part of the handle

The upper part of the handle is prepared in advance for the reason that after gluing the handle to the shank, processing the upper part will be difficult. Also, during processing, you can scratch the blade, which is highly undesirable. According to the markings applied during the preparation, holes for rivets are drilled. A rod of suitable diameter is inserted into them. It allows you to firmly connect both parts of the workpiece and will not allow them to move during processing.

Forming occurs with the help of files and sandpaper. At this stage, it is important to remember about the allowable dimensions of the limiter, the sub-finger recess.

The final processing is carried out using sandpaper with a grit of 800. Before gluing, all parts must be thoroughly degreased. This can be done with acetone or thinner. After the degreaser has dried, glue or epoxy can be applied.

Making staves

The adhesive fastening of the handle to the shank is not reliable. To avoid breakage of the handle, wooden plates must be fastened with rivets. Rivets are made of metal, which is not subject to corrosion. It can be non-ferrous alloys or stainless steel. You can also use a copper or brass tube as rivets.

A blank of future riveting is sawn off from a bar of suitable length. It should be 2-3 millimeters longer than the thickness of the handle. Clamping the riveting in a vise, use a hammer to flare one end. It should look like a fungus at one end of the rod. Further, the riveting, previously lubricated with epoxy glue, is inserted into the holes in the handle and is also flared on the other side of the handle. For flaring a rivet made from a tube, it would be best to use a ball from a bearing.

Shaping the handle

After the glue has dried, proceed to the processing of the handle. First, with the help of a needle file, the protruding parts of the riveting are ground. Then, with a rough rasp, the wood blank is shaped. First, the profile of the knife handle is formed. Grind the tree until the metal of the shank appears. Then the sharp corners are ground down and the handle is shaped into a shape that fits well in the hand.

Grinding and varnishing the knife handle

Finishing is done with sandpaper. Gradually increasing the graininess, it is necessary to remove all the coarse marks from the coarser grained paper. It is enough to complete the process of grinding the knife handle with 600 grit paper. The last step in the manufacture of the handle will be its impregnation.

There are several ways to impregnate the handle for better preservation. These are oil impregnation, wax impregnation or varnishing.

Each of the methods has its own advantages and disadvantages. So, for example, wax must first be melted by heating it, and heating adversely affects the strength of the glue with which the handle is glued. Oils need to be updated periodically. And the lacquer is only a surface protection function.

The final line in the manufacture of a knife from a circular saw will be its final sharpening. To do this, it is best to use a sanding block made from a wooden plank. Sandpaper with a grit of 1000, 1500 and 2000 is glued onto even boards, one grit on each side. A piece of leather is also glued to the board for sharpening. With a little practice, as well as gaining skill, you can sharpen the knife so that it cuts the paper on its weight and shaves the hair.

So, with a minimum of tools and skill, but with the necessary knowledge, you can make an excellent knife from a circular saw. The characteristics of a homemade circular saw knife are often higher than store-bought counterparts in the budget segment. Is there still room on the saw blade after making one knife? Another knife needs to be made!