Stainless steel fasteners have good ductility and corrosion resistance, and are increasingly used in photovoltaic solar power stations. However, improper use will cause the bolts and nuts to be unable to be unscrewed after being matched, that is, "locked", commonly known as "bite", which will cause some trouble to the construction personnel. Based on the construction experience of multiple projects, the engineers of Jugao New Energy analyzed the causes of the locking of stainless steel fasteners and concluded effective methods to prevent the locking of stainless steel fasteners.
Reduce friction coefficient:
(1) Before use, check whether the thread is rough, whether there is iron filings or dirt between the threads, and make sure that the thread surface is clean and these things will often lead to lockup;
(2) Before use, you can use butter, molybdenum disulfide, mica, graphite or talc to lubricate the fasteners, and wax dipping is currently the most commonly used method;
Correct operation method:
(1) The screw must be perpendicular to the axis of the thread, and not inclined;
(2) During the tightening process, the force must be uniform, and the tightening torque must not exceed the safe torque;
(3) The speed and force of screwing in should be appropriate, not too fast or too big, use torque wrench or socket wrench as much as possible, and avoid using adjustable wrench or electric wrench;
(4) Avoid using under high temperature conditions, do not rotate fast when using, to avoid rapid rise in temperature and cause locking; (such as using electric wrenches, etc.)
(5) The use of washers can effectively prevent over-locking.