Material:
Hat: Aluminum
Positioning ring: aluminum
Screw: 300 series stainless steel
Spring: 300 series stainless steel
BN surface treatment:
   Hat: black
   Screw: black
Brief introduction of non-loosable screws, also known as non-loosable, spring screws, and non-loosable screws. It is the pressure riveting and the expansion riveting on the mounting plate, and the position of the plate and the plate is fastened by screws.
The composition of the captive screw is divided into several components:
  1. Screw part (the other end of the thin plate of the chassis is fastened by it, the general material is carbon steel and stainless steel, and the head has a cross or a slot to facilitate tool tightening)
2. Hand-twisting sleeve (usually straighten the pattern, the material is usually aluminum, sometimes it needs to be blackened by aluminum oxidation)
3. Pressure riveting sleeve (rivet on the panel and rely on it)
4. Spring (to facilitate the extension and retraction of the screw and keep the whole part from falling out)
After the production of each component is completed, assemble it into one body and squeeze the hand-twisted part to make it and the pressure riveting part are inlaid together through the spring to form a complete spring panel screw.