Fasteners are usually made of cold-heading steel.In terms of variety classification, in addition to ordinary carbon steel, the steel used in fasteners also includes stainless steel, superalloy steel, aluminum-magnesium alloy, Monel alloy and so on.Among them, stainless steel and non-ferrous metals account for about 5%-7% of the total consumables, in addition to which they are mainly cold heading wire.The steel grades of cold-heading steel wire and wire rods are generally low- and medium-carbon high-quality carbon structural steel and low-alloy steel.Low-carbon cold-heading steel is mainly used for cold-heading nuts.The materials used for bolts and screws are mainly medium carbon steel (ML35 and SWRCH35K), which have reached grade 8 and above after quenching and tempering treatment.
The manufacture of fasteners can be steel, non-ferrous metals, stainless steel, titanium alloys or other engineering materials. The processing method can be thermal processing or cutting, but more than 90% of the products manufactured by this process have high accuracy, good quality and high production efficiency. China's fastener industry has maintained a steady double-digit growth for three consecutive years.Although the proportion of applications of non-ferrous metals and composite materials is increasing year by year, the role of steel used in high-strength fasteners is irreplaceable.
Fasteners are basic mechanical parts and are in great demand. Usually bolts, screws, rivets, etc. are used to ensure safety or generally do not consider the impact of temperature, harsh environments or other dangerous working conditions.Commonly used materials are carbon steel, low alloy steel and non-ferrous metals.However, on certain occasions, fastener materials need to meet the conditions of severe corrosion or high strength, and many stainless steels and ultra-high-strength stainless steels have emerged.