There are actually many sizes of self-tapping screws or specifications of self-tapping screws on the market, so we can describe them as dazzling. There are also many specifications for the size of self-tapping screws. In the eyes of those of us who do not know how to do, these The size of self-tapping screws is enough, but it is not the case. Just like when we use self-tapping screws, we only know their size, and if we don’t know their size and specific specifications, they will appear more or less in use. The inconvenience.

For example: when we use self-tapping screws, we may find that either the self-tapping screws are small, or the self-tapping screws are too large. It takes a lot of comparisons to install these furniture or other objects. If you know Basically understand the size of self-tapping screws based on their specifications, so that in use will greatly save our time to do other things. Then friends will ask. What are the sizes and specifications of self-tapping screws? Today the author will take you to learn more about the specifications and sizes of self-tapping screws.

The head shape of the self-tapping screw has round head, flat head, semi-countersunk head and countersunk head. The material is generally carburized steel, and the surface hardness of the material after heat treatment is not less than 45HRC. Compared with the threads of ordinary screws, when the same major diameter is used, the pitch is larger and the minor diameter is slightly smaller, which has been standardized. Self-tapping screw materials can be divided into two types: carbon steel and stainless steel. Among them, carbon steel is usually made of 1022 medium carbon steel. Usually used on doors, windows and iron sheets.

There are thirteen general sizes of self-tapping screws, such as: T1.2 T1.4 T1.6 T1.7 T2.0 T2.3 T2.5 T2.6 T3.0 T3.5 T4.0 T4.5 T5 .4. 
 
The specifications of self-tapping screws are:   
GB/T 5280-2002 "Threads for self-tapping screws" stipulates the thread specifications for self-tapping screws (screws for thin metal plates) from ST 1.5 to ST 9.5.  
GB/T 5285-1985 "Hexagon head tapping screws" This standard specifies hexagon head tapping screws with thread specifications from ST 2.2 to ST 9.5.  
GB/T 6563-2014 "Hexagonal head self-extruding screws" This standard specifies the hexagonal head self-extruding screws with thread specifications of M2~M12. This standard applies to hexagonal head self-extruding screws.