Analysis of the Causes of Stainless Steel Screw Locking and Resolute Solution

Stainless steel fasteners will lock up during use. The locking phenomenon has its own objective factors. Because stainless steel and carbon steel have inherent differences, stainless steel has good ductility, but the hardness has a certain gap with carbon steel. Stainless steel bolts and nuts will produce a thin layer of chrome oxide on the metal surface during the assembly and locking process. It has anti-corrosion effect. When the stainless steel fasteners are locked, the pressure generated between the teeth is The heat will destroy and erase the chromium oxide layer, causing the metal tooth to directly block/shear, and then sticking. When the sticking phenomenon continues (usually no more than one full caliper), the stainless steel fasteners will be completely locked and can no longer be removed or locked. Usually a series of blocking, shearing, sticking, and locking actions occur in just a few seconds.

一; the external cause of the lock phenomenon of stainless steel fasteners:

1, tooth damage or foreign matter sticking can cause lock-up phenomenon,
2. Excessive force or too fast tightening will cause the temperature to rise rapidly and lock up.

二, preventive measures to prevent the locking of stainless steel fasteners during use:

1; the length of the bolt should be selected appropriately to lock the nut and expose the nut one to two pitches.
2; bolts must be kept clean, lubricant can be added properly
3; the nut must be screwed perpendicular to the axis of the bolt, do not tilt
4; use torque wrench or socket wrench as much as possible to avoid using adjustable wrench or electric wrench
5; When using at high temperature, it must be cooled, and do not rotate quickly when using, so as not to cause the temperature to rise rapidly and cause lockup.
6; During the tightening process, the force must be uniform, and the force should not exceed the safe torque (with the safety torque meter)