As a common part of fasteners, screws are used in a wide range. Their types can also be divided into various types according to different methods.The following Chinese Standard Parts Network summarizes and shares the following types of methods based on their knowledge of screws. .
1. Fastener screws are divided into machine screws and self-tapping screws.
Machine screw: the external thread is screwed together with the corresponding internal thread.
Self-tapping screw: only external thread-type, the screw itself has a high hardness, self-tapping into a thread when assembled when the forming hole of the main body part has no thread.
2. According to production standard: American system (ANSI), international standard (ISO), Japanese system (JIS), German system (DIN), yellow system (BSW). (Non-standard Huai parts can be produced according to customer requirements)
The common letters of screws are indicated by the following letters:
(1) Cylindrical head-C (cheese)
(2) Spherical stigma-B (binding)
(3) Pan head (flat round head) -P (pan)
(4) Oval-T (truss)
(5) Countersunk head-F (flat)
(6) Oval countersunk head-0 (oval)
(7) Round head-R (round)
(8) Hexagon head-H (hexagon)
(9) Hexagon washer head-HW (hexagonwasher)
(10) Basin washer head-PW (Pan washer)
3. According to the number of thread spiral lines, it is divided into: steel teeth, fast teeth (single wire, double wire), high and low teeth, triangular teeth of A self-tapping screws; B standard screw thread pitch of machine screws.
4. According to the screw material, it is divided into: low, medium carbon steel, alloy steel, copper, aluminum, kick, stainless steel, etc.