Self-production of metal tools without professional equipment is a very challenging task with many risks and limitations. It is generally not recommended to do so because it is difficult to meet the quality and performance requirements of industrial production, and it may also bring safety risks due to improper craftsmanship. But if it is only used as a very limited exploration and learning attempt, you can refer to the following extremely simplified steps that may not be successful in making usable tools： ### Material preparation 1. **Choose the right metal material** -For example, high-speed steel (such as W18Cr4V), which has high hardness, wear resistance and thermal rigidity, is suitable for making tools. You can look for waste high-speed steel tools (such as milling cutters, drill bits, etc.) as a source of materials. These waste tools may be found in some machining workshops or second-hand markets. -You can also consider using some alloy tool steels, such as CrWMn steel, which has good hardenability and wear resistance, and is relatively easy to obtain and process. 2. **Material pretreatment** - Clean the collected waste metal materials to remove oil stains, impurities, etc. from the surface. You can soak in a chemical cleaner and then rinse with water. -Cut the material so that it roughly matches the size blank of the required tool. You can use a saw (such as a hand saw or a small table saw) for cutting, and try to ensure that the cutting surface is as flat as possible. ### Tool blank processing 1. **Roughed appearance** -Use a fitter's file to rough out the cut blank, and file out the approximate shape of the tool, such as the contour of the tool body, the preliminary shape of the edge, etc. This requires certain fitter skills and patience, and gradually approaches the target shape by constantly filing. -You can also use a small hand-held grinder to initially grind the blank to remove some larger margins, but pay attention to controlling the grinding volume and grinding temperature to avoid overheating of the material and affecting the performance. 2. **Determine the edge angle** -For simple tools, such as ordinary cutting tools, you can refer to common edge angles for processing. For example, the front angle of the turning tool is generally 5°-20°, and the rear angle is 6°-12°. Use a simple measuring tool such as an angle ruler to roughly determine the angle. - Mark the position and angle of the edge on the blank for subsequent processing. ### Heat treatment 1. **quenching** -If it is a high-speed steel material, the quenching and heating temperature is generally 1270℃-1285℃. The heating time depends on the size of the material, and then oil-cooled quenching. However, in the absence of professional heat treatment equipment, this step is very dangerous and difficult to precisely control. You can try to use a small gas stove or coke oven for heating, but you must pay strict attention to temperature control and safety protection to prevent accidents such as fires and explosions. -For alloy tool steels, such as CrWMn steel, the quenching temperature is generally 820℃-840℃, and oil-cooled quenching. Similarly, operate the heating equipment carefully. 2. **tempering** -The quenched tool needs to be tempered to eliminate the quenched stress and improve the toughness. The tempering temperature is generally determined according to the tool material and performance requirements. For high-speed steel tools, the tempering temperature is usually 560℃-580℃, and the tempering is 2-3 times; the tempering temperature of alloy tool steel is generally 150℃-200℃, and the tempering is 2-3 times. -You can use an ordinary heating furnace (such as a small box-type resistance furnace, but usually there is no such equipment) or use a simple heating method, such as placing the tool in the heated sand, keeping it for a period of time after reaching the tempering temperature, and then slowly cooling. ### Sharpening and finishing 1. **sharpening** -Use a hand-held grinding wheel or oilstone to finely grind the edge of the tool to achieve a sharp edge. When grinding, pay attention to maintaining the angle accuracy and surface finish of the edge. You can use manual push-pull to grind the oilstone to gradually improve the sharpness of the edge. -For some more demanding tools, you can use a small sharpener (if you can find a suitable simple model) to assist in sharpening and improve the efficiency and accuracy of sharpening. 2. **Surface treatment** -You can use sandpaper to polish the surface of the tool to make its surface smoother. Gradually transition from coarse sandpaper to fine sandpaper, such as initial polishing with 80 mesh sandpaper, and then fine polishing with 200 mesh, 400 mesh, 800 mesh or even finer sandpaper. -You can also try simple anti-rust treatment such as blackening the surface of the tool. For example, soak the tool in a heated sodium nitrite solution for a certain period of time, so that a black oxide film forms on its surface, which plays a role in rust prevention. However, this kind of treatment requires certain chemical knowledge and operating experience, and the treatment effect may not be ideal. It should be emphasized again that this method of making homemade metal knives has great limitations and does not meet industrial production standards.