From The Ergoweb® Learning Center


Dan MacLeod, CPE, MA, MPH

Common issues

wrenching2 Intro2
Heavy repetitive motions;  awkward positions; vibration

Using wrenches can potentially involve heavy and/or repetitive motions, often in an awkward working position. Some power wrenches also create vibration and shock to the wrist.

Common options for improvement

Hydraulic wrenches

Hydraulic1 Hyraulic2
Large hydraulic wrench and power source on cart Low profile head, in use (

Hydraulic wrenches are commonly used in process industries, like power plants, but are seldom used or known in manufacturing and assembly operations. Hydraulic wrenches are powerful, provide a smooth force, and are precise for torque control.

Usually, the wrench head requires more clearance than a socket, but newer models are getting thin. Furthermore, depending on the situation, the hydraulic wrench can be connected to a socket with a shaft extension.

A hydraulic pump is required, typically carried in a cart, which can restrict mobility. On the other hand, the cart can be turned into a kind of workstation for using the wrench.

Powered open end wrenches

OpenEnd1 OpenEnd2
Pneumatic tube nut wrench (

Powered open end wrenches tube nut (up to 17 ft. lbs.)

Torque multipliers

TorqueMultiplier1a TorqueMultiplier1
Manual torque multiplier With hold down (


New England Turbo

newenglandturbodiesel ks tools


Impact wrenches

OLYMPUS DIGITAL CAMERA Impact wrench support
Arm to support heavy tool in awkward position

An impact wrench is a commonly used power tool for heavy nuts. As its name implies, it creates rotational force an internal hammering mechanism, effect for turning

air gun, torque wrench

concern for effect of vibration [link future] and shock. Vibration wraps and gloves can be used, but can also increase grip diameter excessively.

Battery powered

Manual impact wrenches/drivers

ManualImpactDriverWithBits Swench
Manual impact driver Swench  (

Over 4500 ft. lbs. smaller ones available


Geared extension

Impact wrench geared2 Impact wrench geareda