Before use, confirm whether the mechanical properties of stainless steel fasteners can meet the requirements of use, such as the tensile strength of screws and the guaranteed load of nuts. The length of the screw should be selected appropriately, and the nut is exposed to 1-2 pitches after tightening. Before use, check whether the thread is rough, whether there is iron filings or dirt between the threads, these things often cause lockup. The fasteners can be lubricated before use: it is recommended to use butter, molybdenum disulfide, mica, graphite or talc for lubrication. At present, wax dipping is commonly used for lubrication and anti-locking.
Note the use of stainless steel fasteners:
a. The speed and force of screwing in should be appropriate, not too fast or too big. Use torque wrenches or socket wrenches as much as possible, and avoid using adjustable wrenches or electric wrenches. Too fast will cause the temperature to rise rapidly and cause lock-up.
b. In the direction of force, the nut must be screwed in perpendicular to the axis of the screw.
The use of washers can effectively prevent the problem of over-locking.
Locking or seizure often occurs on fasteners made of stainless steel, aluminum alloy and titanium alloy materials. These metal alloys themselves have anti-corrosion properties. When the surface is damaged, a thin oxide layer is formed on the metal surface to prevent Further corrosion. When the stainless steel fasteners are locked, the pressure and heat generated between the teeth will destroy the oxide layer, causing blockage or shearing between the metal threads, and then adhesion. When this phenomenon continues to occur, the stainless steel fasteners will be completely locked and can no longer be removed or continued to be locked. Usually this series of blocking, shearing, adhering, and locking actions takes only a few seconds, so a correct understanding of the use of these types of fasteners can prevent this phenomenon
