Ads
related to: bolt and nut preload calculatoramazon.com has been visited by 1M+ users in the past month
Search results
Results From The WOW.Com Content Network
The most common usage is to describe the load applied to a fastener as a result of its being installed, i.e., before any external loads are applied (e.g., tightening the nut on a bolt). Preload in such cases is important for several reasons. First, a tightened bolt experiences only a small fraction of any external load that will be applied ...
The preload target can be achieved by a variety of methods: applying a measured torque to the bolt, measuring bolt extension, heating to expand the bolt then turning the nut down, torquing the bolt to the yield point, testing ultrasonically, or by applying a certain number of degrees of relative rotation of the threaded components. Each method ...
Nut is rotated into position with very small torque applied. Once the external stretching force is removed, the preload is established; heat tightening is based on stretching the bolt by heating it. Once the bolt is expanded, the nut is secured using the turn-of-the-nut method. Upon cooling, a desired preload is achieved as the bolt contracts.
The ball screw was invented independently by H.M. Stevenson and D. Glenn who were issued in 1898 patents 601,451 and 610,044 respectively. Early precise screwshafts were produced by starting with a low-precision screwshaft, and then lapping the shaft with several spring-loaded nut laps [citation needed].
Multi-jackbolt tensioners (MJT) are an alternative to traditional bolted joints. Rather than needing to tighten one large bolt, MJTs use several smaller jackbolts to significantly reduce the torque required to attain a certain preload. MJTs range in thread sizes from in (19 mm) to 32 in (810 mm) and can achieve 20 million pounds-force (89 × ...
It is therefore beneficial in high-frequency high-load situations with a higher risk of fatigue related failure, like a bolted down cylinder head, to use torque to yield bolts. [ citation needed ] The torque applied to the fastener must be determined such that it does not contribute to a service condition where the fastener enters a low-cycle ...