1. The grip of the steel file

(1) The grip method of the large file: the right heart is against the end of the wooden handle of the file, the thumb is placed on the top of the wooden handle of the file, the other four fingers are bent under the wooden handle, and the thumb is used to hold the wooden handle of the file. Depending on the size of the file and the intensity of the force, there are a variety of positions.

(2) The holding method of the middle file The right hand holding method is roughly the same as that of 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 The right index finger is straight, the thumb is placed on the wooden handle of the file, the index finger is against the edge of the file, and several fingers of the left hand are pressed against the middle of the file.

(4) How to hold a smaller file (assorted file) Generally, only the right hand is used to hold the file, the index finger is placed on the file, and the thumb is placed on the left side of the file.

2. The filing posture

The correct filing posture can reduce fatigue, improve filing quality and efficiency. The standing posture of a person is: the left leg is bent forward, the right leg is straight behind, the body leans forward more than (about 10°), and the center of gravity falls. on the left leg. When filing, the legs should stand still, and the body should reciprocate by the flexion and extension of the left knee. The movements of the arms and the body should be coordinated with each other, and the full length of the file should be fully utilized.

3. The use of filing knives

The straight motion of the file when filing is the key to filing. There are two types of filing force: horizontal thrust and vertical pressure. The push is mainly controlled by the right hand, and its size must be greater than the filing resistance to file away the chips. The pressure is controlled by the two hands, and its function is to make the cutting teeth penetrate 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 the two hands must change with the change, so that the torque of the pressure on the two hands on the workpiece is equal, which is the key to ensure the straight movement of the file. The file movement is not straight, and the middle of the workpiece will bulge or produce a drum-shaped surface.

The filing speed is generally 30 to 60 times per minute. Too pleasant, the operator is easy to fatigue, and the cut teeth are easy to blunt; too slow, the cutting efficiency is low.