RR794 - Vibration measurements on torque multipliers

It was brought to HSE's attention that torque multipliers were being used instead of impact wrenches in some instances in the workplace. Given that torque multipliers are purely rotary machines, the vibration level is likely to be much lower than that on an impact wrench. HSL had not previously measured the vibration magnitudes associated with the use of torque multipliers and so were asked by HSE to see whether they are a practicable alternative to impact wrenches and to investigate the differences in vibration exposure associated with their use.

When comparing HSL measured emission values with field measurements, the emission values are lower than the field measurements, indicating that the risk is underestimated by the emission values. However the risk from vibration exposure associated with the use of the machines is very low.

The number of vibration exposure points incurred from use of a torque multiplier when processing 100 nuts is approximately ten times lower than would be incurred with an impact wrench, however it would take three times longer.

A torque multiplier may be the preferred choice of tool if an operator is subject to vibration exposure from using other machines, as very few vibration exposure points will be incurred from its use.

This report and the work it describes were funded by the Health and Safety Executive (HSE). Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.

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Updated 2021-04-23