The solution to bolting problems (Vibration; High Torque). Superbolt tensioners are designed as direct replacements for hex nuts. They can be threaded onto a new or existing bolt, stud, threaded rod or shaft. The main thread serves to position the tensioner on the bolt or stud against the hardened washer and load bearing surface. Once positioned, actual tensioning is accomplished with simple hand tools by torqueing the jackbolts that encircle the main thread.