Non-standard screws are frequently used in daily life, and they are widely used in many fields such as watch glasses, large train ships, and space shuttles. Screws are an invention in people's production. According to the application field, it is also the pride of mankind. So how do you use the screws?
The role of non-standard screws:
The main function of the non-standard screws is to link the tools that fasten the parts, which can also be called shaped screws. There are many screws that do not need to be nuts when connecting. Of course, the basic non-standard screws that do not use nuts are the key to the link mechanism.
Non-standard screws
Non-standard screw material:
In general, non-standard screws are made of high carbon steel, medium carbon steel, low carbon steel, and other materials. Carbon content in carbon steel is distinguished from low carbon steel, medium carbon steel, high carbon steel and alloy steel. Low carbon steel C% ≤ 0.25% Domestically known as A3 steel. Basically known abroad as 1008,1015,1018,1022 and so on. Mainly used for 4.8 bolts and 4 nuts, small screws and other products without hardness requirements. (Note: Drilling nails are mainly made of 1022 materials.) Medium carbon steel 0.25% <C% ≤ 0.45% Domestically known as No. 35 and No. 45 steel, and abroad basically referred to as 1035, CH38F, 1039, 40ACR, etc. Mainly used for 8 grade nuts, 8.8 bolts and 8.8 grade hexagonal products. High carbon steel C%> 0.45%. At present, no alloy steel is basically used in the market: alloy elements are added to ordinary carbon steel to increase some special properties of steel: 35, 40, chromium molybdenum, SCM435, 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, the main components are C, Si, Mn, P, S, Cr, Mo