Torque wrench accuracy

[tim wood]

I’ve had my torque wrench for many a year. It’s well used ( not really abused!)
It’s one of the basic type where the setting is achieved by twisting a marked barrel and pulling until it clicks.

I don’t really know how accurate it is. I know that this can be tested but that seems a faff and probably expensive. Does anyone have experience of these ? Do they go out of calibration?

Tim

[rfs1957]

Hi Tim,

My approach would be to do nothing.

I have four, for different ranges, and some of them are 25 years old ; but they’re mechanical, and - contrary to some metallurgical misconceptions - steel does not go « off ».

I don’t believe there's anything on the Jag that is super critical, and as there are almost no torque figures given for so many of the fasteners that would be littered with specified torques on a modern car, my feeling is that the design was meant to fend for itself in the field.

And so it has proved.

An easy way to allay any fears you have for, say, head bolt torques, is to test your wrench against someone else’s - you can face one off against the other, as it were.

Cheaper than a test certificate anyway

[mgcjag]

Hi Tim...simple checks here https://www.onallcylinders.com/2021/12/ ... %20to%20go.

[chrisfell]

Important advice in the above that I always follow - untension the wrench when finished.

I occasionally check the calibration using a spring balance pulling on the handle while the square drive is anchored in a vice. Simple and effective.

[tim wood]

Thanks guys,
I’m going to have a play with it later today. Will let you know how I get on.

Tim

[Series1 Stu]

I occasionally check the calibration using a spring balance pulling on the handle..........

Presumably the spring balance is suitably calibrated?

[bitsobrits]

Touche

[chrisfell]

"Presumably the spring balance is suitably calibrated"

Of course, by the 1kg weight I'd previously suspended from it.

And that 1kg weight was calibrated on the kitchen scales.

And the kitchen scales were calibrated using a 1 litre jug of water.

And the jug of water was calibrated by suspending it from the torque wrench at precisely 500mm from the centre of the 1/2" square drive, winding the tension down until it clicked.

Then with reference to the time of day, the atmospheric conditions, basic trigonometry adjusted by Euler's constant and the number I first thought of, I hoped that ateast one of the measurements was accurate.

[Series1 Stu]

[Fspp369]

Hi PM me I’ve got the bit of kit I think you need.
Peter.

[mgcjag]

Don't be shy....share what it is

[tim wood]

Followed a few you tube videos on this. Checking calibration seems simple using weights at certain lengths along the shaft.
I reckon that mine is ok