Rotabolt - Bertfelt Teknik AB

Accurate, Reliable, and Economical Bolt Load Control

RotaBolt is a brilliant patented solution that ensures a bolt is tightened to the required load tension effectively, reliably, and economically while allowing for easy checking of that load tension during operation.

Incorrect load tension – The root of most fastening failures

In nine cases out of ten, when a flange leaks or a bolt loosens or breaks due to fatigue, the root cause is incorrect load tension – typically too low.
Even the best torque wrenches can be inaccurate by up to ±40%. Hydraulic wrenches are similarly unpredictable. When the wrench is removed, the joint settles– affecting washers, threads, and gaskets – causing the final load tension to be much lower than required.

Real-Time Tension Checks – without tools or disassembly

With Rotabolt, each bolt can be easily checked for correct load tension during tightening and while in service – without removing the bolt or using tools.
Each bolt is equipped with a load tension indicator (rotor). Simply press the rotor with your thumb and forefinger. If it moves, tighten the bolt until the rotor becomes fixed.

Reduced Costs and Lower Risk of Failure

RotaBolt significantly reduces both installation and inspection costs, as well as the risk of system failure.
Because RotaBolt ensures correct bolt tension, engineers can more precisely specify bolt size and quantity during the design phase – optimizing both safety and material usage.

Accurate to ±5% – Measuring Elongation, Not Torque

RotaBolt ensures bolt load tension with an accuracy of ±5%.
It measures bolt elongation, which directly reflects the applied load – unlike torque-based methods that are affected by friction and other external factors.
This makes it ideal for checking bolt security during service – especially under stress from temperature changes, pressure fluctuations, or vibration.

Engineered for Harsh and Demanding Environments

RotaBolt is suitable for use in damp, dirty, or high-temperature environments – successfully tested in conditions up to 630°C.
It is used wherever simple, fast, and dependable load checking is critical.

RotaBolt is manufactured by RotaBolt Ltd, a trusted part of the international James Walker Group.