Locking or seizing often occurs on screws made of stainless steel, aluminum alloys and titanium alloys. These metal alloys have anti-corrosive properties. When the surface is damaged, a thin oxide layer is formed on the metal surface to prevent further corrosion. . When the stainless steel screws are locked, the pressure and heat generated between the teeth will destroy the oxide layer, causing the metal threads to clog or shear and stick. When this happens continuously, the stainless steel fasteners will be completely locked and can no longer be removed or continued to lock. Usually this sequence of blocking, shearing, adhering, and locking operations takes place for a few seconds, so correct understanding of the use of such fasteners can prevent this.
Hardware screws
1. Correct selection of product: Before use, confirm whether the mechanical properties of the product can meet the requirements of use, such as the tensile strength of the screw and the guaranteed load of the nut. The length of the screw must be selected properly to tighten the nut to a distance of 1-2 teeth.
2. Before using, check if the threads are rough and whether there are iron or dirt between the threads. These things often cause lock-up.
3. The fasteners can be lubricated before use: it is recommended to use grease, molybdenum disulfide, mica, graphite or talc for lubrication, and it is generally used to lubricate anti-locking.
Precautions
1. The speed and force to be screwed in should be appropriate, not too fast and too large. Use torque wrenches or socket wrenches as much as possible to avoid using adjustable wrenches or electric wrenches. Excessive speed will cause the temperature to increase rapidly and cause lock-up.
2. In the direction of force, the nut must be threaded perpendicular to the axis of the screw.