Prevailing Torque Locknuts - When They Don't Work, What Happened?

You can't be in the locknut business very long without encountering someone having problems with locknuts in their applications.  When a locknut manufacturer's registered quality system includes rigorous quality controls, their parts pass the qualification tests, and there are still problems on the customer's assembly line, what happened? The short answer is that sometimes there are ...Read More

Prevailing Torque Locknuts - How They Work

The prevailing torque in prevailing torque locknuts comes from localized plastic deformation to an interference fit with continuous sliding during assembly.  Let's break this down. Localized plastic deformation - Some of the starting threads need to be able to accept the mating part (bolt, say) before the prevailing torque begins.  The interference is therefore localized to not include the ...Read More

Prevailing Torque Locknut Testing and Qualification

In addition to inspections common to all internally threaded fasteners (nuts), prevailing torque locknuts are inspected for prevailing torque performance. Prevailing torque is the resistance to assembling or disassembling the locknut and mating part when the assembly is not clamping (not developing tension in the mating part)...Read More