What can happen to bolts if not torqued correctly?
If the bolt comes loose, this clamp force weakens. Loose bolts are not just an irritating nuisance. If the joint is not quickly retightened, the application may begin to leak fluid or gas, the bolt may break, equipment may become damaged, or catastrophic accidents may occur.
How do you know if a bolt is torqued properly?
Mark the tightened fastener and surrounding application. In the tightening direction, begin to slowly apply force to the tool until the first movement in the fastener is noted. The reading recorded is a good indication of the original torque applied to the joint. This is the best way to determine residual torque.
Is it safe to reuse torque-to-yield bolts?
Torque-to-yield (TTY) head bolts are designed to stretch when used. Once stretched, they are not as strong as before. Because the tightening procedure permanently stretches the bolts, there is a risk of breakage if reused.
How do I know if my torque is loosening?
Simply take a bolt or screw that is tightened and start to loosen it progressively. Be keen and record the exact torque reading when the fastener becomes loose. The torque value necessary to loosen the fastener will be the approximate force that was exerted to the joint.
What happens when you put too much torque on a bolt?
Typically, an under torqued bolt will deform and be unable to provide as much clamping force as needed. An over torqued bolt will break. The Tools You Need and How to Care for Them Torque wrenches will measure the amount of torque being applied in either analog or digital formats.
Can a torque wrench be used to tighten head bolts?
It won’t give you the accurate torque readings you need when torqueing down the head bolts. Save yourself a headache – use a high-quality torque wrench to tighten the head bolts in at least 3 steps. Tighten until you get to the needed torque specification.
Can you use a TTY bolt after it has been torqued?
And since there is no way to tell how many times a bolt has been reused, it doesn’t make any sense to reused TTY bolts – the risk far outweighs the replacement cost of used bolts.
How much torque is used to preload a bolt?
Approximately 50% of the torque applied to a bolt is used to overcome the head-bearing friction, and about 35% is used to overcome the thread-contact friction. Therefore, 85% of the torque value is used strictly to overcome friction and only 15% is used to preload the bolt.