Your fastener distributor is one of the best resources available to field questions regarding the safe and effective use of fasteners. When the time comes to dismantle and/or reassemble, the question of whether or not to reuse nuts and bolts tends to come up. Is it possible? Does your distributor recommend reusing products, and why or why not?
The Experts Answer
In some cases it is possible to reuse fasteners. Only fasteners that have never been torqued beyond their yield strength may be used again. If overtorquing is suspected or can be confirmed, those fasteners cannot be relied on to provide a durable, secure joint.
Fasteners that have been exposed to extreme heat or are corroding in any way should not be reused. Have the fasteners been modified, such as with paint, lubrication or other treatment? These modifications also make fasteners unsuitable for a second application.
Used nuts, bolts, washers and other types of fasteners should not be reused on critical joints or applications, no matter what their condition. If the joint has been designed for loosening and tightening that action is permitted. But excessive movement, even in predesigned applications, will eventually wear the nuts and bolts down and render them unstable.
Your fastener distributor should also let you know that a used bolt should never be used in combination with a new nut. Neither should a used nut be paired with a new bolt. Tension, heat and age will have pushed the used fasteners beyond their yield strength, resulting in deformities that may be invisible to the naked eye. Deformed threads will not mate well with new threads, creating an uneven and unstable joint.
In general, reusing nuts, bolts, washers and other mechanical fasteners is not a good idea. If you have any doubts about the condition of the fastener in question, discard it in favor of new fasteners. That choice will always result in a stronger, more durable joint.
Any money that you would have saved by reusing the fasteners will be overshadowed by damage and downtime cause by fastener failure. Your fastener distributor is committed to providing durable products, as well as offering advice and guidance regarding the safe use of those products.
