To date, there is a fairly large number of different knives for sale. However, this tool can be made independently, if you know some of the nuances of processing and hardening.
Knives made of files are distinguished by high strength and durability.
How to harden a knife from a file?
Making a blade from a file should begin with drawing up a sketch. First of all, it will be necessary to draw the shape of the blade, the handle, to depict the method of its fastening. As a result, the paper should display the tool that you plan to get in reality. As a blank, you can use a file that can be purchased at any building supermarket or use an old tool. The tool is made of durable carbon steel, which has excellent cutting qualities.
In most cases, there are old files that are most practical. Of them, you can easily make a sharpened blade at home.Back to table of contents
What preparatory work will need to be done?
Drawing knives from a file.
The process of hardening the knife itself is simple, since the file is a steel billet, which is designed for such work. If it is possible to find old-style tools that are made of homogeneous carbon steel, then it will be possible to get a quality construction.
The elements that will be necessary in order to temper a knife from a file:
- knife handle;
- brass rivets;
- ferric chloride;
- epoxy resin;
- abrasive sandpaper;
- machine for sharpening tools.
How is the workpiece fired?
First you need to burn the file. It is recommended to hold the device for 4-5 hours in a heated stove or stove and allow it to cool with it. However, an ordinary stove that runs on gas will do. The essence of roasting is to allow the metal to ignite at temperatures of 650-700 °, then gradually cool. It is necessary to burn only the part that will be used as a blade in the future. Consider this point if you plan to use a gas stove.
When baking the workpiece, it is necessary to calcine the metal to 700 degrees.
The stove can give only a small temperature, therefore it will be necessary to additionally build a heat shield. This can be done much easier than it might seem at first glance. The goal is to make a small hill above the file of nuts and bolts, on which the plate is made of metal. As a result, the temperature from the burning gas will go much less into the air and heat the instrument more.
Heated area will need to sprinkle with ordinary kitchen salt. Salt will be used as an indicator: if it melts when heated, then everything is done correctly. If the salt does not melt, then you will need to increase the temperature and repeat the process again. During heating under the plate, the tool should have an even color of the red-hot billet, which should be held for about 3-4 hours.
After firing, the temperature should be reduced in stages. First of all, reduce the burning force by ¼, after 30 minutes a little more tighten. Actions must be continued until complete cooling. In no case should not ignore this recommendation. If you miss this point, the metal may begin to crumble.Back to table of contents
Knife shaping, hardening and tempering
After the blade is sufficiently calcined, you need to cool it.
In the next step, you will need to clamp the file in a vice in the workshop, after which cut off the extra elements. The file can also be grinded on a coarse abrasive disc, giving the tool used a completely different shape - the pattern of the future blade. If the product will be made out of wood or any other overhead plates, then in the handle it will be necessary to prepare holes for rivets or to cut a groove using the grinder.
The next step is hardening the blade. Quite often, masters are guided by the degree of quenching by the glow of the heated billet. You should know that this is a mistake. True results can only be achieved by using a magnet. If the heated metal does not react to the presence of a magnet, then this means that the quenching was brought to the necessary degree.
To warm up the made knife it is necessary evenly.
The only exception is the handle section - in this case it will only be necessary to warm up the 3 cm section at the base of the blade. For this, it is recommended to use a burner that is able to give a higher temperature.
After this, it will be necessary to prepare a container with water in which in the future it will be possible to cool the workpiece. When the uniform color of the metal is obtained and the magnet stops reacting to it, the product will need to be warmed up for a few more minutes, after which it will be plunged into the prepared container. If such actions are performed with precision, then glass can be scratched with this metal, which is the best sign of excellent hardening.
Due to the high internal pressure, hardened metal can begin to break, crack and crumble during sharpening. To avoid this, you must perform a vacation - a process by which the internal stress is relieved with a slight decrease in the hardness of the material.
You should be aware that metal drills are made in the same way. The process itself is quite simple: you need to put the product in the oven and heat it for 1.5 hours at a temperature of at least 200 ° C. The file must be cooled with the oven.Back to table of contents
How to properly finish the blade and handle?
After the shaping, quenching and tempering of the tool are completed, you can proceed to the final processing of the blade. In this case, any available tools that are intended for grinding can be used. This can be sandpaper, brushes for working with metal, felt, grinding machine and other elements. It is not necessary to grind heavily, since in the future it will be necessary to etch. In this case, you will need to give the blade smoothness and bring its base in a neat look.
Forms of knife handles.
Before etching, on the handle you can install the lining of any material you like. The blank can be wrapped with a leather strip, everything will depend on personal preferences. In the first case, the final treatment will have to be performed immediately after etching. If you plan to wrap the workpiece with leather, then this should be done at this stage. You will need a length of at least 0.5 m. First of all, you need to perform a simple winding in order to understand how a knife may look like in a similar design, whether a leather strip has enough length, how convenient the tool to be made is in your hand. If there is still a desire to produce such a winding, you should first unwind the handle, then apply a special adhesive mixture to the back of the strips of leather. Then you should carefully wrap the handle.
If you want to handle the handle with a tree, you should know that this process is more complex. The holes for the rivets will need to be filled with epoxy resin, then fasten the handle with rivets and fix it in a vice until the resin is completely cooled. In this case, you will need to use 2-3 rivets. When the resin dries, the handle will need to give the desired shape, but do not hurry with the final processing. The first step is etching. If there is a shop selling radio components nearby, you can buy ferric chloride in it, in which you will need to pickle the blade until you get a matte gray color.
The film, which will be formed on the blade, will be able to protect it from corrosion, because it does not need to be removed in any case. If it is not possible to acquire such iron, then etching can be carried out using the available tools: vinegar, lemon juice or ground potatoes. The blades will need to be cleaned of any contamination, as during etching they may even show fingerprints. If this happens, you will need to remove the oxide film and perform all actions again.Back to table of contents
How to sharpen the blade manufactured knife?
When the etching is completed, the epoxy can dry out. At this stage, you will need to make the final processing of the handle and sharpening the blade. If the handle was made of wood, then it will need to give the shape you like, then polish and wax. When the handle is fully ready, you can proceed to the most difficult stage - sharpening. This process is recommended to be done manually using an ordinary grindstone. You should know that by using an electric sharpener you can easily overheat the metal. For editing, you can use iron musat - a round rod with notches, which in most cases comes complete with blades for the kitchen.
The knife, which is made according to the rules, will be very sharp, at the same time every person will be able to sharpen it, even by using an ordinary stone. Such a tool can be used in the workshop, to carry out such work, from which ordinary blades quickly whip and dull.
Hardening a knife from a file with your own hands is easy enough if you follow the sequence of actions and have all the necessary tools and materials.