Mechanical Expansion Bolts

Mechanical Expansion Bolts

Superbolt was the world’s first to revolutionize nuts and bolts with multi-jackbolt tensioning (MJT) technology. Our technology has been proven in tens of thousands of successful installations and we continue to develop a multitude of solutions to solve the next generation of bolting challenges.

Superbolt EzFit

EzFit mechanical expansion bolts offer tremendous radial expansion and joint clamping power in one bolting system. They are specially designed for rotating couplings or alignment systems that require the bolts to transfer forces in shear.

This innovative product replaces large fitted or interference fit bolts, no modifications required. The key to this solution is the split expansion sleeve that mates with the customers' machined holes. The split sleeve requires less tolerance on mating parts than is traditionally required with interference fit, saving critical machining time.

Standard Range

EzFit mechanical expansion bolts can be designed using latest FEA technology for any type of coupling with bolts of diameter 20mm (3/4″) or upwards.

Unique features and advantages of both hydraulic and mechanical expansion sleeve coupling bolts can be combined to best suit your specific requirements.

A Type

  • Mechanical expansion bolt for threadless bore
  • Access and operation from one side
  • Dimension on request

B Type

  • Mechanical expansion bolt for blind holes
  • Access and operation from one side
  • ∅ 28 – 165mm

C Type

  • Mechanical expansion bolt for through-holes
  • Access and operation from both sides
  • ∅ 28 – 165mm

Superior performance

EzFit mechanical expansion bolts are used on many critical applications throughout various industries, such as couplings on ship drives, turbines, engines, generators, compressors, and replacement for dowel pins in transmitting transversal loads on foundation anchors.


  • Quick and easy to install and remove – only hand tools needed
  • No need for special high-powered tools and bolt deep freezing
  • Saves money over alternative solutions in time and tooling
  • Reusable split sleeve that springs back to original size, use after use

Testing & Certification

Superbolt products have been rigorously tested and approved by independent institutes as well as certification authorities.


  • ABS (American Bureau of Shipping)
  • DNV (Det Norske Veritas)
  • LRS (Lloyd’s Register of Shipping)

Customer success stories

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