Stainless steel screws are not easy to rust but often occur locking, carbon steel screws do not often happen this situation, what is the reason for this?
Locking or biting occurs on fasteners made of stainless steel, aluminum alloy and titanium alloy. These metal alloys themselves are corrosion resistant. When the surface is damaged, a thin oxide layer is created on the metal surface to prevent further corrosion. When the stainless steel fastener is locked, the pressure and heat generated between the thread will destroy the oxide layer, causing the metal threads to block or shear, and then the phenomenon of adhesion.
When this phenomenon continues to occur, the stainless steel fastener will lock completely and cannot be removed or relocked. Usually this series of blocking, cutting, adhesive, locking a series of action occurs in just a few seconds, so we should understand and use this type fastener correctly, then we can prevent this phenomenon.
Some friends will wonder why stainless steel fasteners sometimes have locking problems, but carbon steel fasteners do not often occur similar phenomenon? This should be seen from the two materials of stainless steel and iron. Stainless steel standard screws are soft and have good ductility. We take SUS316 stainless steel standard parts to compare with the grade 8.8 iron standard parts in surface hardness, SUS316 is softer than grade 8.8 iron standard parts. Stainless steel has the better ductility, but its surface hardness will be lower than carbon steel what had made heat treatment.
Anzhikou Hardware Technology Co., Ltd. has 20 years experience in screws production and customization, we can provide you with suitable fastener solutions according to customers’ requirements.

