Torque wrench question

Special Circumstances

"Treated" my self to a pretty cheap and possibly nasty torque wrench.

I already have a 1/2 inch 40Nm to 200Nm (or something like that, Lidl yoke).
Rather than just guessing on smaller stuff I got a draper 10-80Nm 3/8 one.

Not sure if it was dodge from the box or if I unwound it too far but it just doesn't want to go to 80. Seems to be maxed out somewhere around 67Nm. I unwound it a bit beyond the lowest marking but not so much that it was about to come apart or anything.

So...
1) Can unwinding these too far cause gross accuracy problems (10-15Nm)?
2) This sound reasonable? - Tighten a bolt to 40Nm with my other wrench, try with new wrench. Do the same for 60 and if they match up then I guess I can be confident enough in it?


Scale on these seems poor, the 0 never seems to want to match any of the decade marks. Internal threads feel nasty. I don't expect or need +-2Nm accuracy just 20ish or 25 ish. I'll only need it 10 times in 5 years probably so if it is accurate ish then I'll suffer it but wouldn't particulary recommend it.

I honestly do not need a super dooper Teng or whatever. You may have one and it may earn its money for you (good choice if you are a pro) , or maybe you just like the bling (congrats on your disposable income), but I cannot justify one.

nd

Yeah I think testing it against your other wrench should be a decent test of it's accuracy.

There`s a few vids on youtube of how to test accuracy.

Special Circumstances

Duuur - I never think of searching youtube for anything except music videos.
OK, looks like a good idea. Really I should have spent a bit more I think - my time spent testing this thing will probably be a multiple of the total time spent using it over the next few years. False economy I guess, depending on how you value your time.

Roger Mellie Man on the Telly

The Halfords Professional ones are good. Not particularly cheap though.

nd

I have a lidl/aldi one and one of these

http://www.ebay.ie/itm/Draper-1-2-Square-Drive-Beam-Type-Torque-Wrench-0-21Kg-M-150Lb-Ft-Sq-Dv-34487-/171541038518?pt=LH_DefaultDomain_3&hash=item27f0a485b6

as far as I know they are suppposed to be fairly accurate at lower torques.

whizbang

I was always told to unwind fully after use, to reduce pressure on the spring and prevent it going weak.

But i did come across one that never seemed to engage the spring properly when tightening, so it would be way wrong. Easy to tell when it was off though.

Interslice

Special Circumstances wrote: »

"Treated" my self to a pretty cheap and possibly nasty torque wrench.

I already have a 1/2 inch 40Nm to 200Nm (or something like that, Lidl yoke).
Rather than just guessing on smaller stuff I got a draper 10-80Nm 3/8 one.

Not sure if it was dodge from the box or if I unwound it too far but it just doesn't want to go to 80. Seems to be maxed out somewhere around 67Nm. I unwound it a bit beyond the lowest marking but not so much that it was about to come apart or anything.

So...
1) Can unwinding these too far cause gross accuracy problems (10-15Nm)?
2) This sound reasonable? - Tighten a bolt to 40Nm with my other wrench, try with new wrench. Do the same for 60 and if they match up then I guess I can be confident enough in it?


Scale on these seems poor, the 0 never seems to want to match any of the decade marks. Internal threads feel nasty. I don't expect or need +-2Nm accuracy just 20ish or 25 ish. I'll only need it 10 times in 5 years probably so if it is accurate ish then I'll suffer it but wouldn't particulary recommend it.

I honestly do not need a super dooper Teng or whatever. You may have one and it may earn its money for you (good choice if you are a pro) , or maybe you just like the bling (congrats on your disposable income), but I cannot justify one.

Had a similar problem with that lidl one when I got it first. Sent it back for a new one. Do the same don't use it. I sheared a bolt on the 1/2 turn after 60Nm. It was reading between setting so I didn't know if it was on 55+ or 65+ or whatever. Hard to explain. I get on to them, probably just a bad unit. QC probably isn't at the teng/snap-on level! I'd be the same btw. No point in spending big money on tools you rarely use better off paying a mechanic! I only have a few high quality tools, mostly ratchet spanners in the common 10 12 13 17 sizes. Just pick them up individually in the motor factors now and then when I'm buying parts. Bit of a discount then.

Don't use torque wrenches anymore... If I was rebuilding an engine I would but no plans to do that any time soon!

Hi,

I purchased the autoXS torque wrench set in Aldi last October. It
works fine except the knurled handle is 90 degrees. 0 lies halfway
between two reading on the scale and 6 is bang on. With a result I am
never sure if it's reading high or low or whether it has even been
calibrated properly at all.

I has been like this since I bought it. I have attached two images to
show exactly what I mean.

Can I get a new one as it is still under warranty?

whizbang

If you use a spanner often enough, you get a feel for torque. 6 is not a big difference either way, you can get variations of 6 just by being clumsy.
Is the spec wet or dry; what allowance do you use for rust on threads...?

I think if you are good enough to know the wrench is not right, than you are good enough not to have to depend on the torque wrench anyway..;)

Flood

Cheap torque wrenches are a no no plus calibrating them off you tube is another no no.

doctorchopper

To answer your question, no it shouldn't effect the torque wrench, but you shouldn't back them off all the way either, they should be stored at the minimum setting when not in use

Special Circumstances

doctorchopper wrote: »

To answer your question, no it shouldn't effect the torque wrench, but you shouldn't back them off all the way either, they should be stored at the minimum setting when not in use

Yeah I've a feeling the offset was there from the factory - POS from day one.