Bolt stretch is an important factor in the retention of preload. As torque is applied to a bolt, the stress on the bolt increases. This stress results in bolt stretch that is proportional to stress and active bolt length (or grip length). Almost all bolted joints experience some relaxation. Some of this occurs very quickly due to embedment relaxation. Phenomena such as differential thermal expansion, creep, external or dynamic forces, etc. may take place over time. The amount of preload lost on a joint is a function of the total relaxation relative to the elasticity in the bolting system. For bolted joints where springs are not used, the elasticity may be approximated as bolt stretch. 

Solon's Bolt Stretch Calculator allows users to quickly calculate bolt load, stress, and stretch for a given joint design and input torque. This information can be useful in evaluating whether a connection can be expected to lose significant load. The calculator also highlights connections with length to diameter ratios that will be prone to greater losses. If appropriate, the user can also link to selection tools that greatly reduce the loss of preload in their particular application.

Simply complete the fields with information relative to your application and our calculator will automatically filter the selection to recommend Solon Belleville springs and washers along with quantity and stacking arrangements necessary to meet your application requirements.

Please complete the form below to access our online bolt stretch calculator. 

*It is ultimately user’s responsibility to determine product suitability. Solon Manufacturing Co. is not responsible for product that is ordered incorrectly, misused, or misapplied. Contact a Solon engineer for recommended guidelines for product use. 

Required Fields *
Contact Information