Users of stainless steel fasteners often reflect why stainless steel fasteners sometimes have a problem of lock-up. However, when using carbon steel fasteners, similar phenomenon does not occur frequently. Is it because stainless steel fasteners are of softer material and carbon? Why are steel fasteners relatively hard? That's right! Stainless steel and carbon steel are essentially different. Stainless steel has good ductility, but its hardness is somewhat different from that of carbon steel. The hardness of the austenitic stainless steel grade 316 heading A4-80 can only reach the 8.8 grade equivalent to the carbon steel hardness grade. However, this argument can only be said to be half right.
Thread galling often occurs on fasteners made of stainless steel, aluminum alloys, and titanium alloys. These types of metal alloys have inherent anti-corrosive properties and can be damaged when the surface is damaged. A thin layer of oxide (chromium oxide in the case of austenitic stainless steel) is produced on the metal surface to prevent further corrosion. When the stainless steel fastener is locked, the pressure and heat generated between the dentition will destroy and wipe off the chromium oxide layer between them, so that the metal dentine will directly block/shear, and then the sticking phenomenon will continue to occur ( Usually no more than one complete tooth diameter will cause the stainless steel fasteners to lock completely and can no longer be removed or locked. Usually this series of blocking - shearing - sticking - a series of locking actions takes place in just a few seconds, so to understand the characteristics of stainless steel products and to follow the correct operating procedures are to prevent the stainless steel fasteners lock The first step to death