Torque Wrench Calibration

Where can I get my 2 torque wrenches calibrated?

Preferably same day in London

How accurate do you need them to be? How much do you believe them to be out by?

Before paying for it to be done, I'd test it against 2 others (ideally more expensive/newer ones) and compare it against their values for a given bolt at several different torque values.

Sorry if you have already checked this way and are looking to get them calibrated as a last resort, don't mean to teach my grandmother to suck eggs

[Balky001]

Halfords to a re-calibrating service but not sure if its same day - worth calling though

[embee]

you can do a reasonable calibration check yourself, not inspection quality standard, but good enough to decice whether you're confident in the scale.

Ideally hold the square drive in a vice with the wrench horizontal.

1 litre of water weighs exactly 1 kg, or 9.8 Newtons.

Hang a light plastic bucket on the end of the wrench, measure how long the effective lever is, add water and see at what adjustment the wrench clicks. A bucket will usually hold up to 10 lts.

e.g. 5 lts water = 49 Newtons, hung at 0.5m gives 24.5Nm.

On the other hand it might be easier to have it checked.

I've done what Ceri says, used my calibrated Britool to check others, simply connect them together with a square drive, set the calibrated one to a known value, and adjust the other till they both click together (more or less).

Originally Posted by embee

you can do a reasonable calibration check yourself, not inspection quality standard, but good enough to decice whether you're confident in the scale.

Ideally hold the square drive in a vice with the wrench horizontal.

1 litre of water weighs exactly 1 kg, or 9.8 Newtons.

Hang a light plastic bucket on the end of the wrench, measure how long the effective lever is, add water and see at what adjustment the wrench clicks. A bucket will usually hold up to 10 lts.

e.g. 5 lts water = 49 Newtons, hung at 0.5m gives 24.5Nm.

On the other hand it might be easier to have it checked.

I've done what Ceri says, used my calibrated Britool to check others, simply connect them together with a square drive, set the calibrated one to a known value, and adjust the other till they both click together (more or less).

Sounds like a good method. However, do not try doing up a bolt to a certain torque with one wrench thought to be accurate, and then seeing how much torque the other wrench requires to undo it again. They won't agree as it always takes less to undo it again!

Mike

Originally Posted by embee

you can do a reasonable calibration check yourself, not inspection quality standard, but good enough to decice whether you're confident in the scale.

Ideally hold the square drive in a vice with the wrench horizontal.

1 litre of water weighs exactly 1 kg, or 9.8 Newtons.

Hang a light plastic bucket on the end of the wrench, measure how long the effective lever is, add water and see at what adjustment the wrench clicks. A bucket will usually hold up to 10 lts.

e.g. 5 lts water = 49 Newtons, hung at 0.5m gives 24.5Nm.

On the other hand it might be easier to have it checked.

I've done what Ceri says, used my calibrated Britool to check others, simply connect them together with a square drive, set the calibrated one to a known value, and adjust the other till they both click together (more or less).

You'll need to torque the vice jaws up, else you have wet feet/garage/shed etc.. if it decides to slip of end of wrench!!