Superbolt Tensioners


Superbolt tensioners offer you simple and cost-effective tightening of large size bolts. Your joints can be tightened with high accuracy without requiring specialized skills or heavy tooling.
A wide range of tensioners is available in the standard series, as well as an unlimited capacity to create special designs to meet your unique needs.



Superbolt multi-jackbolt tensioners take high preload requirements and break them down into manageable torques using the jackbolts threaded through the nut body. They remain easy to install, even on larger sizes, compared to standard hex bolts.

Additional information


Nord-Lock Group, Superbolt


Industrial, Manufacturing, Mining, Oil & Gas, Transport

Technical Guide

Joint Guide

Stud bolts
Superbolt tensioners used on studs into blind tapped holes. Tightening in pure tension means studs will not gall in the tapped hole and can be easily removed.
Common application of double ended studs use Superbolt tensioners and a reaction nut on the other end. Flexnuts add elasticity to the stud, increasing fatigue life.
Tapped holes
Superbolt tensioners are often used into blind tapped holes. Tensioners’ bolt heads are more compact and fit into tighter areas; additionally, they also reduce the number of parts.
Superbolt tensioners can be provided to fit completely into small counterbores. An internal installation removal hex allows for easy turning into position.

Installation Tips

Importation considerations when applying Superbolt tensioners for various field application scenarios.

Centering of washer on thread
Make sure the washer is not resting on one side of undercuts or radius of mating studs.
Material with low strength
A thicker and larger washer or an additional washer may be necessary when materials with low strength are used on the joint.
Large or slotted holes
An additional washer or a large washer is necessary to transfer the bolt load to a supported surface.
Space requirements
Check for space restrictions for socket and wrench combination.
Tensioner at the end of stud
An additional distance spacer may be necessary to bring tensioner closer to the end of the stud for proper socket fit.
Very long through-stud
A special tensioner with a larger circle of jackbolts may be necessary to properly access the jackbolts for tightening.