1. Plane filing

Plane filing is the most basic filing. There are three commonly used filing methods:

(1) Forward filing method 　

The file is moved horizontally or longitudinally along the surface of the workpiece, and the file plane can be cut to obtain a straight file mark, which is more beautiful. It is suitable for filing, filing flat or filing lines along the workpiece.

(2) Cross filing method 　

Is to file the workpiece sequentially in two crossing directions. Because the file marks are crossed, it is easy to judge the unevenness of the filed surface, so it is easy to file the surface flat. The cross file method is faster to remove chips, and is suitable for flat rough files.

(3) Push file method 　

Hold the file symmetrically with both hands, and push the file with both thumbs for filing. This method is suitable for narrower surfaces that have been filed and have a small machining allowance to correct and reduce the surface roughness.

2. Inspection of the quality of the filing plane

(1) Check the straightness and flatness of the plane. Use a steel ruler and a square ruler to check by the light transmission method, and check a few more parts and perform a diagonal check.

(2) Check the verticality 　

Use a square ruler to check by the light transmission method. The reference surface should be selected, and then the other surfaces should be checked.

(3) Check the size 　

Use a steel ruler and a vernier ruler to measure several times at different size positions according to the dimensional accuracy.

(4) Check the surface roughness 　

Generally observe with eyes, but also can use the surface roughness template for comparison inspection.