Torque Wrench

[Russell9318]

A rule of thumb when selecting a torque wrench is to generally aim for a tool that will have most use in 70% of the scale, that is above the lower 20% and below the upper 10%. The reason for this is the lower 20% is not calibrated as the weight of the wrench can over ride the sensitivity. It is always good to work below the upper 10% to avoid working the tool at full capacity and work the tool in it's optimum range.

Micrometer Adjustable or click type wrenches lose sensitivity in the coil springs at the lower end of the scale however, with good quality wrenches you rarely have problems in the upper scale range as long as the micrometer is wound back to zero after completing the job, these coil springs lose their memory if left too long under compression.

For most automotive work a 1/2" drive wrench between 10-140ft.lbs / 10-185Nm will do the job and also be very manageable. Things like diff pinions and hub nuts can get a lot higher but for the main, look for a wrench where you will be working in the 70% scale range.