The CD pattern screw is also a deep knowledge in the international community. The example of a firm screw for each data application is not the same, but there are some basic rules:
First, the tooth pitch of the screw can be divided into three categories: machine teeth, plastic screws, wood screws, or wall screws. Screw pitch is importantly related to the density of the locked data. The greater the data density, the smaller the pitch.
1. The coarse teeth in the teeth refers to the standard screws used in each place; the fine teeth may not be the same according to the same requirements, but also refers to the non-standard screws and are used in exceptional occasions.
2. The pitch of plastic screws is also probably not the same. For example, PP, PE and other soft data can increase the pitch, so it is not easy to slide the teeth; and POM, PC and other high-density data can use smaller screws.
Second, there are many types of CD head screws and groove type, usually based on surface and tamper, or other needs not the same, this is more intuitive.
Third, the tail of the control of the complex shape. Nothing we use to control the common tail, tail, slot, triangle, cone and so on. These shapes have several important results: positioning, tinning, self-tapping, self-locking, and other effects. Depending on the efficacy, you can pick different tail requirements.
Fourth, self-tapping screws are divided into two major categories of applications: plastics and hardware.
1. Self-tapping is adopted in every state of plastic, but there are some places outside of special needs. However, it is important to pay attention to the fact that different plastic applications do not have the same CD pattern screws with different pitches and tail shapes, and they need to be especially careful when they are exposed to heat and stress.
2. Hardware self-attack Generally adopt triangular screw, the pitch is the same as the machine screw, the triangular screw has the characteristics of self-locking and self-tapping, but it cannot be disassembled and reinstalled on weekdays.