Duo and Mono series multi-stage tensioners are versatile and reliable hydraulic bolt tensioners suitable for high load and tight space applications. Duo tools feature multiple hydraulic stages to give a small tool diameter to fit into tight radial spaces. Mono tools feature low height profile to use when there are overhead obstructions.

Optimised for use on wind turbines they have been designed for long-life, low-maintenance use and are suitable for use on single bolts or grouped together for multiple tightening of bolted joints. Duo and Mono tensioners are extensively used for slewing rings, powergen applications, structural and all critical bolting.

Duo and Mono tensioners are designed for speed.

Fast spring piston retract, geared nut run-down and spring located

sockets, improve process time on each tensioning operation.

High cycle life, over-stroke protection and the latest seal technology ensure low maintenance operation to keep projects on schedule.

These tools generate high loads. They are designed to give an applied load equal to 95% loading on 10.9 type bolting.