A “Superbolt” or “multi-jackbolt tensioner (MJT)” is a direct replacement for hex nuts, covered nuts, bolts, etc. They spin onto your existing bolt or stud and provide a better way to bolt up your joint. They consist of three components.

If you are tightening a nut greater than 1″ in diameter, you may find Superbolts useful, since the torque you need to tighten conventional nuts and bolts exponentially increases as the size increases. Our products solve this problem and only require hand/air tools to install or remove any size MJT. They eliminate the need for time consuming and unsafe bolting equipment such as sledgehammers, hydraulic wrenches and stud heaters.

Multi-jackbolt tensioners come in a variety of sizes and configurations. If you are experiencing bolting problems such as leakage, thread galling, unsafe working conditions or are using expensive methods and find it difficult to properly bolt your joint, Nord-Lock bolting technologies are the solution for you.

multi jackbolt tensioners

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Nut-style 

Superbolt multi-jackbolt tensioners (MJTs) replace existing hex nuts. Only hand tools are required for installation and removal of any size tensioner. Safe, accurate and economical! We have a wide range of standard series, as well as an unlimited capacity to create special designs to meet your unique needs.

 

 

2. Bolt-style

Bolt style Superbolt multi-jackbolt tensioners (MJTs) replace existing studs or bolts. Ideal for applications with tapped holes, or where threading a stud into a nut would be impractical. The outside diameter is smaller than a nut type tensioner on a stud, allowing MJTs to fit into tighter areas.

 

 

3. Flexnuts

Flexnuts are used in combination with Superbolt tensioners and are designed to flex out at the bottom and flex in toward the top of the nut. This distributes the bolt load along many threads, adds elasticity, and prevents stress concentrations in the first few threads.

For through hole applications we have developed the Superbolt flexnut, which is a reactive nut that is able to flex elastically.