Using a Torq wrench

*Moangroan* · 12 Sep 2012 at 17:24

I have an awkward nut that will need doing to the proper torque.

I can probably access it easy with a my torque wrench and instead of a socket on the end, use a crows foot.

Does anyone know if I use a crows foot will this change the torque value at all. Would the calibration be off using this....thx

-westy- · 12 Sep 2012 at 17:28

As long as it's secure, then the value shouldn't change at all. Out of interest, what nut is it? What's it on?

Matt82 · 12 Sep 2012 at 17:39

What westy said sounds absolutely fine. I'd have no issues using a crow foot.

Dogbreath · 12 Sep 2012 at 18:03

Of course a crowsfoot socket will change the torque applied to the fastener, basic GCSE physics should have taught this.

See this website to calculate the correction factor.

-westy- · 12 Sep 2012 at 18:08

I wouldn't have thought that there would be much of a correction factor?

Dogbreath · 12 Sep 2012 at 18:19

-westy- said:
I wouldn't have thought that there would be much of a correction factor?

The correction factor will depend on the length of the crows foot compared to the length of the torque wrench, as per the link.

e.g. a 1" crowsfoot and a 12" torque wrench would overtighten by (1/12)*100 = 8.3% if you didn't correct the setting. For a longer torque wrench the error becomes smaller.

blueboy2001 · 12 Sep 2012 at 23:22

Be very careful using a torque wrench on anything you can't get a decent amount of turn on. I've snapped a couple of bolts with mine when doing things up where due to space I couldn't get more than about 45 degrees of turn at the end of the wrench. The wrench never clicked and as they were pretty high torque bolts I kept going.

The only time I've snapped a bolt is using a torque wrench - I usually just guesstimate and have never had a problem.