The hydraulic torque wrench was invented in 1968 by a man named George Sturdevant, in the Oil and Gas capital of Texas. He was the leading innovator and has led the way to today’s technology for controlled bolt-loading.

The Dangers  

The most dangerous part of a hydraulic torque wrench is the reaction arm which abuts against a stationary object to stop the wrench from turning around the fastener. This reaction force is produced by high pressure and accidents, such as pinched fingers, are a common occurrence.

Safe Methods

Since 1994 it has been possible to torque bolts without the use of a reaction arm through the design of innovative torque wrenches and accessories. Reaction arm free torquing is only possible with the use of a reaction washer, or proprietary castle nut with a built-in sleeve. The reaction washer acts a stationary object underneath the nut, eliminating the use of reaction arms.

This method is not seen to be cost-effective on existing bolted connections as the same proprietary equipment can only be then used to remove the nuts, not including the cost to replace all existing bolts with the reaction washer.

Cost-effective Safety

To continue the use of current torque wrenches and tightening of existing bolted connections, the Back-Up Nut can be used.

When using cassette type torque wrenches the reaction point is close to the link which is powered to turn the bolt. When hands are positioned this close to moving parts, hands and fingers can become crushed and pinched. Although handles have been designed for technicians to hold onto, so they’re not holding directly onto the wrench, they have also been proven to act as a secondary hazard.

With the Back-Up nut, technicians can use the tool to securely hold torque wrenches in position on the bolt and then step back while the wrench is being powered. Therefore creating distance between the reaction point and moving parts.

safety nut

The Back-Up Nut

– Compatible – No retrofitting required

– Zero downtime –Current tools and operations can continue

– Instant safety – Once purchased they can be used onsite

– Available in Boxed Sets to suit a variety of bolt sizes.