Torque screwdrivers

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I wonder how many people, including the 'expert :slap ' scheme assessors, actually know how to use a torque driver, especially on heavy stranded cables?


I was taught to use a torque wrench by an old fitter.

Tighten to 80% torque and give the bolt and yourself a rest.

Torque down to 100% in one go and leave it alone after that.

Re-torquing can actually slacken a bolt due to a slight kickback when the wrench reaches the set point.

If I had to use a torque driver for terminals I’d use the above method.

 
I was taught to use a torque wrench by an old fitter.

Tighten to 80% torque and give the bolt and yourself a rest.

Torque down to 100% in one go and leave it alone after that.

Re-torquing can actually slacken a bolt due to a slight kickback when the wrench reaches the set point.

If I had to use a torque driver for terminals I’d use the above method.


which is pretty similar to what I was taught by my grandad (another old fitter), except he preferred to do a third of the torque, rest, then two thirds, cup of tea, re-do two thirds and then apply final torque.

the extra stages I think were due to him working on engines and suchlike where most of the torqued bolts were compressing gaskets where there's a bit more give\relaxing in the gasket between tightening than there is with purely metal/metal fastenings. 

 
If I'd paid the £80 -- £90 for one of these unecessary screwdrivers & it carped out in a short period , I'd be looking for the supplier's normally concealed orifice up which to insert it.

Won't happen however as I too use the British Standard Wristwist driver which seems to have sufficed for The British Standard  Half Century.

New Venture !   I've not been asked to demonstate one either although the serial number of my mains tester was taken last time :C

Why not just chuck it in your tool box and say  " yeah here it is look "

 
which is pretty similar to what I was taught by my grandad (another old fitter), except he preferred to do a third of the torque, rest, then two thirds, cup of tea, re-do two thirds and then apply final torque.

the extra stages I think were due to him working on engines and suchlike where most of the torqued bolts were compressing gaskets where there's a bit more give\relaxing in the gasket between tightening than there is with purely metal/metal fastenings. 
I've torqued up engines before,

Torque to setting,

Settle for 15mins, torque again,

Apparently that's adequate for half million quid engines, can't comment for anything else though, and, that was only in a hobby capacity though

I'm not sure if that's official HRC guidelines.,,,,,,  

 
Top tip: get an old ratchet screwdriver and paint little numbers around the shaft, et voila, torquedriver.

 
I've torqued up engines before,

Torque to setting,

Settle for 15mins, torque again,

Apparently that's adequate for half million quid engines, can't comment for anything else though, and, that was only in a hobby capacity though

I'm not sure if that's official HRC guidelines.,,,,,,  


I've only ever had the pleasure of doing engine work on my trusty old landrover.

Grandad however spent his life working on very serious engines and associated mechanical bits in mining/quarrying machinery, trains, and suchlike 

 
I've only ever had the pleasure of doing engine work on my trusty old landrover.

Grandad however spent his life working on very serious engines and associated mechanical bits in mining/quarrying machinery, trains, and suchlike 
Always good to get 'old hands' knowledge, 

I don't think Joey ever went by any HRC guidance, 

(joey.Dunlop.com) or similar.

 
Torque screwdrivers are a complete waste of money in my opinion,let be honest anything that takes measurements be it a torque driver or a meter should be treated as a precision instrument and handled accordingly.By that logic it follows that anytime it gets dropped it should be recalibrated,now if you think how many times in a week you drop a screwdriver it would spend more time in the calibration shop than in your hands,plus I suppose you shouldn't really keep it rattling around in your toolbox,lets be honest you don't leave your test gear bouncing around loose in the back of the van!

 
Quite agree Phil, it's a get out of jail card for mfrs when it comes to failing terminal connections and combustible CU's! Their legal eagles obviously thought this one up to take liability away from the mfr. 

 
Quite agree Phil, it's a get out of jail card for mfrs when it comes to failing terminal connections and combustible CU's! Their legal eagles obviously thought this one up to take liability away from the mfr. 


I don't see how it is a get out of jail card the heating and cooling effects on terminals as load changes means that they would have to be regularly re-torqued to maintain the specified torque required for a fault free connection

 
Do you think we will see Wago type lever or push connectors in accessories and consumer units in the future - applying a steady spring pressure and making these redundant?

 
Do you think we will see Wago type lever or push connectors in accessories and consumer units in the future - applying a steady spring pressure and making these redundant?


It would be a more sensible solution to the issue than the current round of nonsense we have. Far too sensible for it to actually happen I think.

Something along the lines of the wago din rail terminals type of terminal could be made to work I think.

of course it would result in numpties stuffing more conductors in to each terminal than they are intended for. 

 
Thanks guys. I'm not buying another one as the electrician I'm currently helping out on a biggish job just gave me his with a "I never use it or been asked for it, have it" 

 
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