Several Misconceptions About Fasteners
Jan 14, 2025
Several misconceptions about fasteners
1, Thickened nut
Some people often mistakenly believe that thickening the nut can increase the number of working turns of the thread, thereby improving the reliability of the connection. In fact, the thicker the nut, the more uneven the load distribution between the threads of each turn, which is more likely to cause the connection to loosen.
2, Improper locking
Important bolts should be locked with anti loosening devices after assembly. When using open-ended locking, a common mistake is to use overly thin open-ended locks or half piece open-ended locks for locking; The common mistake of using spring washers for locking is that the opening of the washer is too small and loses elasticity; The common mistake in using locking plates is to lock the locking plates at the corners of the nut; The common mistake with double nut locking is to install thinner nuts on the outside and not tighten them tightly.
3, False solidity
There are rust stains, scale, iron filings, sand particles and other impurities in the threads of bolts, nuts or screw holes, or burrs, mud and other impurities on the joint surface of the connecting parts, which are not removed before assembly. When tightening the bolts, due to the blocking effect of impurities, the surface is tightened very tightly, and the torque value meets the requirements, but in reality, the connecting parts are not truly tightened; In addition, there is another situation where due to the jacking effect of impurities such as oil sludge and scale in the screw hole, although the bolt torque meets the requirements, the workpiece is not tightened. Under such false solidity, vibration, load impact, and temperature changes often cause bolts to loosen quickly.
4, One mother, multiple pads
During installation, sometimes there may be excessive length of bolts after assembly, so some people install many spring washers on a single bolt. As a result, the spring washers are subjected to uneven force during the strengthening process, and some may break, reducing the pre tightening force of the bolt; Or it may generate eccentric loads, reducing the reliability of bolt connections.
