Download NORD-LOCK Expander System Catalogue

Jeysons Industries is Authorised Distributor of NORD-LOCK's Expander System, a permanent solution to lug wears in INDIA.

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.

Superbolt products are an innovative technology for tightening large bolts & studs. MJTs have been proven and established as a preferred solution for bolting in every major industry, all over the world.

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. MJTs ensures a profitable life cycle cost by improving the bolt design for OEM manufacturers, ensuring reliable operation and by facilitating maintenance procedures.

Complete solutions:

From space to deep sea, from small to largem no matter what your bolting challenge, the Nord-Lock Group has done it before. Bring your bolting questions to us, and we will work with you to find the best possible solution.

Custom Solutions:

We can find the solution to any bolting problem. With a focus on secure and reliable joints since 1982, the Nord-Lock Group has a history of thousands of special designs to prove our capabilities. We are highly adaptable to space constraints and environmental conditions that no other bolting systems can match

How do Superbolt tensioners work?

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.

Superbolt tensioners from the Nord-Lock Group consist of three components:
A hardened washer (3) protects your equipment and provides a hardened, flat surface for the jackbolts to "push" against.
The nut body (2) spins on your existing bolt or stud and seats against the washer hand tight (Superbolt nut bodies are typically round).
The jackbolts (1) thread through the nut body and are used to tighten the joint in pure tension, using ordinary hand tools.

Superbolt tensioners working on a bolted joint:

By tightening the jackbolts (1), a strong thrust (axial) force is generated. This thrust force is directed against a hardened washer. Jackbolts have a small friction diameter and can therefore create a high thrust force with relatively little torque input.
The loads are transferred through the nut body (2) which is positioned on the main thread by hand.
A hardened washer (3) is used to transfer the force while protecting the flange face.
The thrust (axial) force of many jackbolts and the opposite reaction force of the main bolt head create a strong clamping force on the flange (4).
The thrust (axial) force from the jackbolt creates an equally strong reaction force in the main bolt (5).

Advantages of Superbolt tensioners

The Superbolt multi-jackbolt tensioner (MJT) takes the high preload requirements in large diameter bolting and breaks it 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 nuts.
Multi-jackbolt tensioners (MJTs) offer many benefits when compared to other common bolting methods. They are fast, safe and easy to use!

•  Tremendous clamping force available.
•  Low torque requirement, only hand tools needed.
•  Safe method for installation personnel.
•  Reduces installation time over common methods.
•  Tightens stud/bolts in pure tension.
•  No thread galling.
•  No need for tight tolerance threads which can seize.
•  Studs will not seize into housing.
•  Tensioner flexibility adds elasticity to studs/bolts to create a better bolted joint.
•  Fits in restricted areas.
•  Provides even tension from stud to stud.
•  Accurate within 10% of specified bolt tension.
•  Ease of removal.