Reasons for stainless steel fasteners being completely locked

Fastener is a widely used mechanical part. Its characteristics are variety of specifications, different functional uses, standardization, serialization, high degree of generalization. Among them, stainless steel fasteners have excellent corrosion resistance, formability, compatibility and toughness in a wide temperature range, which is favored by heavy industry, light industry, daily commodities, building decoration and other industries. Locking (or occlusion) often occurs with fasteners made of stainless steel, aluminum and titanium alloys. These metal alloys are resistant to corrosion. When the surface is damaged, a thin oxide layer forms on the metal surface to prevent further corrosion. When stainless steel fasteners are locked, the pressure and heat between the teeth marks can destroy the oxide layer, causing blockage or shearing between the metal threads, which can lead to adhesion. When this phenomenon continues to occur, the stainless steel fastener will lock completely and cannot be removed or locked. Reasons for locking stainless steel fasteners: Before using stainless steel fasteners, make sure that the mechanical properties of the product can meet the application requirements (such as the tensile strength of screws and the safety load of nuts). In addition, the length of the screw should be selected appropriately, with one or two pitches of the exposed nut after tightening. If there are solder joints and other metal shavings between the teeth marks, this will usually result in locking. Try to use a torque wrench or socket wrench to avoid adjustable or electric wrenches. Because the electric wrench usually causes the locking speed to be too fast, the temperature to rise too fast. Tighten the nut perpendicular to the shaft of the screw and do not tilt. The use of a washer/plate is effective in preventing the lock from being too tight. Stainless steel fasteners correctly choose the brand of product material and performance grade. Matching bolts and nuts of different material grades can reduce locking, but it is necessary to confirm whether the product meets the use requirements before use. The length and specification of bolts should be appropriate, with one or two pitches of exposed nuts as the standard.