Damned torque wrench

The message from "Dave Plowman (News)" contains these words:

Hmmm, must have a word with the wife about my nuts being overtight.

Heat tends to loosen most things. Or a little oil. I wouldn't recommend a nut splitter here, though.

I've got one of these too, bought about 6 years ago and it only gets light usage. Out of curiosity the other week I thought I'd check to see how accurate it was. I clamped the drive end in the vice, set it to

Dead chuffed I was at thinking of this and even more impressed that it worked, although how linear the calibration is likely to be, I know not

- I don't really feel like trying to hang 28l (120Nm) of water on the end to find out!

I can still recall my horror, when first taking on a supervisory role in a aircraft engineering, watching a young 'un tightening a 7/16th nut up with white knuckles and beads of sweat on his brow. I decided it was time to re-educate him.

Same here. You do develop a 'feel'. Though if a torque setting is given I always use it. I'm not so keen on the angle tightening method that seems to be taking over though.

Vin.

The message from "Dave Plowman (News)" contains these words:

Too late - I've already been to the vets and had the half-brick treatment.

been there, done that i was told, when i first got it, to slacken it off when it wasn't used or else it would do something to the srping and it would go out of calibration so what did i do? i wound th ebloddy end off it and looked at the bits and srpings in my hands as i tried to figure out how it all went back together :(

It provides a far more accurate clamping force as friction doesn't come into it - or at least to the same degree.

The message from "Dave Plowman (News)" contains these words:

What a dreadful pun.

It's quite easy to calibrate a torque wrench. You clamp the 1/2" drive-square in a vice so that the wrench is horizontal, then hang a lightweight plastic bucket from the handle and slowly pour water in the bucket until the wrench clicks. Measure the distance from the string attachment to the centre of the drive-square in inches. Pour the water into a measuring jug to determine its weight (1 pt weighs 1.25 lbs). Multiply the two together and divide by 12 (12 inches to the foot, see). Answer is the ft-lbs that made it click. You can even allow for the weight of the bucket if you're fussy.

I did this at several settings and got a calibration graph, and was surprised the wrench was only about 15% out. The graph is now sellotaped to the wrench.

Phil The uk.d-i-y FAQ is at

At college a bloke came in to class to give the lecturer a message. He was walking bent double and talked with a pained voice. After he had gone the lecturer explained that his wife had given his back a good rub with 'Deep Heat' the night before. She didn't wash her hands after and liked to hold on to the part of him that belongs to her during the night.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

: Absolutely. Most fixings on a car ain't critical. If they all were, : there'd be a much greater range of sizes and even threads.

I only tend to use the torque wrench (Norbar - don't mess around with cheaper stuff) for cylinder heads. And even then, I think it's mainly useful for getting the different bolts balanced, rather than to a precise value. Though I do aim for what the book says as close as I can, particularly since DS heads aren't exactly a stock item...

Ian

The great problem with torque wrenches is many don't know how to use them.

Saw a guy in KwikFit leaning on one long after it had clicked. Some seem to think the click is only there to tell you it's almost tight enough.