File operation

1. Clamping the workpiece

The workpiece must be firmly clamped in the middle of the jaws of the vise. The surface to be filed is slightly higher than the jaws and cannot be too high. When clamping the machined surface, a copper sheet or pad should be placed between the jaws and the workpiece. Aluminum sheet.

2. How to hold the file

Holding the file correctly will help improve the quality of the file.

(1) Hold the large file with the right palm against the end of the wooden handle of the file, place your thumb on top of the wooden handle of the file, and the other four fingers bend under the wooden handle. Use your thumb to hold the wooden handle of the file with your left hand. According to the size of the file and the intensity of the force, there can be a variety of postures.

(2) Grip of the middle file　 The right hand grip is roughly the same as the large file, and the left hand uses the thumb and index finger to pinch the front end of the file.

(3) How to hold a small file: Straighten the index finger of your right hand, place your thumb on the wooden handle of the file, put your index finger on the edge of the file, and press the fingers of your left hand on the middle of the file.

(4) How to hold smaller files (assorted files)　 Generally, only use your right hand to hold the file with your index finger on top of the file and your thumb on the left side of the file.

3. File posture

The correct filing posture can reduce fatigue, improve the quality and efficiency of filing. The standing posture of a person is: the left leg is bent forward, the right leg is straightened behind, the body leans forward (about 10°), and the center of gravity is lowered. On the left leg. When filing, stand still with both legs, and rely on the flexion and extension of the left knee to make the body move back and forth. The movement of the arm and body must be coordinated with each other, and the full length of the file must be fully utilized.

4. The use of filing knife

The straight movement of the file during filing is the key to filing. There are two types of filing force: horizontal thrust and vertical pressure. The pushing is mainly controlled by the right hand, and its size must be greater than the filing resistance to file off the chips. The pressure is controlled by two hands, and its function is to make the filing teeth go deep into the metal surface.

Since the length of the two ends of the file protruding from the workpiece changes at any time, the pressure of both hands must be changed accordingly to make the pressure of the two hands equal to the moment of the workpiece, which is the key to ensuring the straight movement of the file. If the file movement is not straight, the center of the workpiece will bulge or produce a drum surface.

The filing speed is generally 30 to 60 times per minute. Too happy, the operator is easy to fatigue, and the file tooth is easy to blunt; too slow, the cutting efficiency is low.