After the file is selected, the reserve of machining allowance is also very important. Since the workpieces to be filed are generally not large, theoretically the filing allowance should not exceed 0.5 mm; if the workpiece is large and the allowance is large, it is obviously time-consuming, labor-intensive and uneconomical to file and process. Machining should be considered. In addition, the following issues should be noted when filing.
(1) Don't use too much force when rasping. Don't think that rasping can remove the most margin in the shortest time. Rough files must be especially careful. This is because the rough files are relatively less sharp. If you don’t pay attention, you will easily gnaw on the machined surface and cause deep machining marks. It is difficult to remove the rough machining in semi-finishing and finishing. Knife marks. At the same time, because the blade of coarse-toothed files is relatively small, too much force will easily make it wear and blunt quickly, and will cause too large chips to stay in the blade, which will affect the filing efficiency of the file, and the service life of the file will also be greatly reduced. . In the filing operation, use force when pushing forward, and gently lift and pull back when backward, to avoid abrasion and scratching of the machined surface of the file blade edge and improve the life of the file.
(2) During semi-finishing processing, paint chalk dust on the fine file to reduce the chip holding space. This can keep the file sharp and avoid excessive chips in the chip pockets from scratching the surface of the workpiece.
(3) When finishing, use files more carefully, and it is required to choose fine files and polished files. When using the knife, you can eat the knife according to the feel, and use force according to the machining allowance. Do not use force blindly and push it back slowly. As long as the correct operation method is strictly followed, the workpiece can be processed to meet the requirements of surface roughness and accuracy.
(4) Do not use oilstone and emery cloth when filing. As long as the correct filing skills are mastered, the processed workpiece will certainly meet the drawing requirements. If you use whetstone and emery cloth, firstly, it will destroy the processing texture, and secondly, if the operation is improper, the edges and corners of the workpiece will be deformed, making the workpiece look lacking in beauty and texture.
