The Nord-Lock Group manufactures patented Superbolt multi-jackbolt tensioners designed to eliminate unsafe and time consuming bolting methods. MJTs replace or retrofit existing nuts and bolts, and only require hand/air tools for installation and removal of any size tensioner.
Thousands of companies have enjoyed the benefits of using our bolting products. Switching from other bolting methods (such as hydraulic torque wrenches and stud heaters) can save you money and increase worker safety. Also, MJT's offer a better bolted connection than conventional hex nuts. Discover all the benefits below!
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, shown to the left.
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. We have many stock items that are available for immediate shipment, and we are able to handle custom jobs quickly. 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.
MJT Brochure: Click here!
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. Superbolt tensioners remain easy to install, even on larger sizes, compared to standard hex nuts.
The advantage is obvious, but how exactly do our multi-jackbolt tensioners achieve this? As you can see in the animation below, the hardened washer is installed first. Then the nut body is threaded onto the existing stud or bolt, hand tight against the washer. The jackbolts are then tightened and thrust against the hardened washer. Accurate preload is achieved on the stud by torquing the jackbolts.
Our bolting technologies come in a variety of custom configurations, meeting the requirements of virtually every type of application. MJTs are available in both nut and bolt style, and we also can supply studs, expansion bolts, flexnuts, thrust collars and more. Visit our products page for more information.
Multi-jackbolt tensioners (MJTs) offer many benefits when compared to other common bolting methods. They are fast, safe and easy to use!
Superbolt tensioners are used in all industries, all over the world. To learn more about how this technology has helped other companies with their bolting challenges, please use the links below:
Over the years, the product types in our multi-jackbolt tensioners range have been tested and approved by several certification institutes and authorities. We have also achieved several design approvals and type approvals for production. Below are some examples:
All of our products can be delivered with additional certificates upon request. Additional certificates should be requested prior to ordering in order to assure proper compliance. For more detailed information on certificates / approvals for a specific product or production site, please contact your local Nord-Lock office.
The Nord-Lock Group has acquired both Superbolt, Inc. and P&S Vorspannsysteme AG (now known as Nord-Lock AG). This exciting combination of the competence of Superbolt and Nord-Lock is unique in the bolt securing industry. We are able to serve global customers with an impressive line-up of safe and cost effective bolting solutions for critical applications.
If you are looking for contact information for either of these companies, see below:
1000 Gregg St
Carnegie PA 15106
Tel: +1 412 279 1149+1 412 279 1149
Fax: +1 412 279 1185
8735 St. Gallenkappel
Tel: +41 (0)55 284 64 64+41 (0)55 284 64 64
Fax: +41 (0)55 284 64 69
For information about Nord-Lock representation in your area, please refer to our contact page.
Achieve high & accurate preload with only hand tools! Replaces existing nuts.
Achieve high & accurate preload with only hand tools! Replaces the existing bolt or stud. Requires less space than nut and stud configuration.
For through hole applications. Ensure an equal load distribution & increase fatigue life of the bolt/stud.
Replaces traditional interference or force fit bolts. Utilizes multi-jackbolt technology.
Unique MJT designs for specific application challenges.