1. To what extent should the screws be tightened? The s […]
1. To what extent should the screws be tightened?
The screws on the phone are live (the screws sometimes loosen naturally...). During the tightening process, the screw extends forward. You can't see it with your eyes, but it does extend. At this time the screw is the time to struggle. It is this force that gives the fixing force. If it is tightened too much, it will loosen. The fixing force will drop sharply.
If you screw it again at this time, it will break. It was a pity that what was about to be completed failed again. How far should the screws be tightened? However, depending on the size, material, and use of the screws, it is difficult to determine the exact value.
2. How to tighten the screws 1
First of all, the screws and tightening objects should be clean. There are foreign objects that cannot be smoothly rotated and cannot be tightly fixed.
It is necessary to observe whether the screw has scratches, burrs, dust, etc., and whether the tightening tools are used correctly? The side of the female screw for installation should also be checked for scratches, burrs and dust. If there are any, they must be removed and prepared. Then start tightening, but try to work in a posture that can be easily applied. The same is true when only small button pitches are used. Incorrect posture work is also easy to twist the screw, each re-tightening will reduce the life of the screw. Also pay attention to pressure. Generally speaking, "Press: twist=7:3".
When tightening, try to screw as much as possible at the beginning to confirm whether the screw can turn smoothly. If you start with a tightening tool, you can tighten even if there is a problem.Ratchet turnbuckle Of course, please pay attention to the tightening size on the side of the female screw. If the screw is longer than the smaller size, the screw cannot move. Use place and purpose of special screws used on semiconductor equipment: Use vacuum screws to fix parts in the process chamber and vacuum. The opening is to shorten the vacuuming time of the cavity and reduce the external air.
Note: It is weaker than the model without opening, so pay attention to the tightening torque!
3. Screw tightening method 2
When using multiple screws to fix parts, pay attention to the tightening sequence. After tightening one, the next one is the furthest away is the most basic. Start with the shape of the example below! The basic of temporary fixation is that when there are screws on the top and bottom, the top and bottom are the other order. Regarding the reinforcement and tightening, follow the above method. After all screws are temporarily fixed, tighten them in order. In addition, the reinforcement and tightening are repeated in order little by little, and tightened to the necessary torque! For temporary tightening, make sure that all the screws are put in, and the purpose of inserting the screws from above is to ensure safety. Before tightening all the screws, be sure to insert the combination of female screws and male screws. At this time, the position of the fixed object must be confirmed. This is the practice of professional work. The upper part is temporarily fixed first, and the lower screw is easy to fix, especially when two people work at the beginning of the human body, the upper part is fixed first and then one person can work safely.