Torque wrench calibration...who does it?

[Billzilla]

My (admittedly 20yr old) china cheapy was actually clicking at 40ft-lbs when I set it at 60. I went and splashed out on a Warren and Brown.

With the threads and underside of the nut/bolt head nicely lubricated, if you are careful you can feel the fastener just go into the elastic deformation zone, then if you keep going, into the plastic deformation zone.
Then it breaks.

[JamesB]

Read a great post on either the Commo or Ford forum where some dude recommended using a torque wrench to undo caliper bolts so you can work out what they were torqued up to originally by reading off whatever torque was needed to undo them.

Nothing like watching a tight-arse that won't buy his own tools, using a recently calibrated torque wrench with a length of pipe slipped over the handle as a cheater, to undo a stubborn bolt ... and then putting the once calibrated torque wrench back in the cupboard as if nothing has happened. Got real shitty when he was banned from borrowing/using the workshop's tools indefinitely.

[spiller]

have the wrench back now. It was out by more than 50% in some cases e.g. when set at 80 ft/lbs was actually clicking at 38 ft/lbs. Glad I got it done!

[tim510]

don't forget to wind the tension out of your wrench when you aren't using it.

[spiller]

^^ yeah I was just reading up on that, says on most sites to wind to the lowest setting when storing away. never knew any of this stuff before.

[silicon]

What was the cost out of interest?

[Rdyno]

With the threads and underside of the nut/bolt head nicely lubricated, if you are careful you can feel the fastener just go into the elastic deformation zone, then if you keep going, into the plastic deformation zone.
Then it breaks.

I can feel that without lubrication, but I tighten hundreds of fasteners a week.

have the wrench back now. It was out by more than 50% in some cases e.g. when set at 80 ft/lbs was actually clicking at 38 ft/lbs. Glad I got it done!

You couldn't feel that?

don't forget to wind the tension out of your wrench when you aren't using it.

I usually leave my click type one at around 100ft-lb I have run over some nuts a few times with my digital one and it is pretty accurate, although it is coming up to it's yearly calibration so I'll see how far it's out.

[Rdyno]

Read a great post on either the Commo or Ford forum where some dude recommended using a torque wrench to undo caliper bolts so you can work out what they were torqued up to originally by reading off whatever torque was needed to undo them.

The person that wrote that is a fucking moron.

[Old Major]

+1 for Torque Calibration Services. He races a historic race car for what it's worth.

HK Calibration would be another option.

[Spammy]

The person that wrote that is a fucking moron.

He was on a Ford/Commodore forums - so goes without saying.

[Fatboy]

The person that wrote that is a fucking moron.

So you've been posting elsewhere huh ?

+1 for Torque Calibration Services. He races a historic race car for what it's worth.

Sponsors. Matty is a drag racer, he's scared of corners...

[spiller]

What was the cost out of interest?

The inspection was $33 and the calibration was another $40. Not bad when the guy drove out to me, tested on the spot, then took the wrench away, re calibrated it and delivered it to me!

[spiller]

You couldn't feel that?.

I was torquing some wheel nuts the other day and 78 ft lbs felt way too easy, hence me getting it calibrated. Did not think it would be that far out though.

[JamesB]

don't forget to wind the tension out of your wrench when you aren't using it.

The recommendation is to set micrometer style torque wrenches to 20% of the maximum rating for storage as the internal mechanism requires a small amount of tension in order to prevent tool failure due to unwarranted tip block rotation. If a micrometer tool has been stored with the setting above 20% the tool should be set to 50% of full scale and exercised at least FIVE times before being used.

Even before I knew about this rule, I had always backed off the tension on my 250 ft-lb rated torque wrench to the 50 ft-lb setting ... simply because at 50 ft-lb, it would exactly fit across the drawer in my 26" tool cabinet.