Torque screwdrivers

[gareth jones]

never seen a domestic (or many industrial) electricians (or mechanics!) using torque, even if they do- was it calibrated and do they have the cert. I've long been using torque on electrical and mech fittings- as one person points out it does cover you for warranty, also if a job specifies a torque, that's what you do- and not over-tighten, which can be just as bad (and annoying). I accept the gear for calibration is a bit expensive for a small firm.

these are pretty good:http://www.wihatools.com/200seri/285vario_s.htm

Facom also do some nice torque control stuff

 

[i=p/u]

youve went into houses , where you know havent been touched for 40 years and they still tight

 

[shagbite]

markiesparkie (post #6) has given a perfect description of the predictable nature of copper, when used as a conductor. it's because of this reason that i believe it would be nigh-on impossible to prove someone negligent, through not following 'manufacturer's torque recommendations'. how would they be able to prove that you left the screws too loose, when you installed them? also - checked on amazon for a 'sonic screwdriver' and all i got was some tat, off dr. who!

 

[nickblake]

youve went into houses , where you know havent been touched for 40 years and they still tight

i did a CU upgrade the other day didnt need a screwdriver as the connections were so loose unscrewed the board from the wall slight pull on each connection and it all fell appart

 

[ExArmy]

I see elecsa will now sell you a roll of stickers saying "this unit has been correctly torqued using a calibrated torque screwdriver" and some tamper evident stickers for sticking over the breakers to stop people un calibrating them. what a joke!

 

[sparkdog]

Yes,they sent me some of these labels with the last thing I bought which was a book.

 

[Toonlad]

I see elecsa will now sell you a roll of stickers saying "this unit has been correctly torqued using a calibrated torque screwdriver" and some tamper evident stickers for sticking over the breakers to stop people un calibrating them. what a joke!

lol all this paper inside would just create a fire hazzard. Unless they insist on firetuf tamper labels

 

[topcat]

I asked the local tool shop about calibration of torque screwdrivers they said they did not do it and that some are only good for so many uses so may be more money than we think if they have to be replaced say every 2 years

 

[Tuttle]

My ELECSA assessor warned me last year that I would need to get a torque screwdriver for consumer units. I asked how's that work then, do you set the torque and it clicks or something, and he replied, I don't know, I haven't seen one yet. So it didn't seem that urgent to me and I ignored it for a bit (hoping that they would come down in price).

I've got my annual assessment coming up again now though so I thought I'd better get on and buy one. I bought a Wiha slim bit set just the other day, looks impressive, the shafts of the screwdrivers are very thin, pretty much the same as a normal non-VDE screwdriver, and it came with a +/- bit for MCBs, ideal for getting at those screws buried deep inside RCBOs, but it cost me nearly 100 quid :thumbs_down:

I haven't had chance to use it in anger yet, as it only arrived the other day, but I've given it a go on an old CU I had lying around. The manufactures instructions indicate that connections should be tightened to at least 2Nm, which works fine for MCB's, etc, but is much to tight for the screws in the N and E bars - I gave it a go and the screwdriver kept going until the copper cores were completely crushed, to the point of breaking off, and the screw hit the back of the terminal block.

I take it that they only mean the screws in the breakers / main switch should be tightened to 2Nm, but this isn't clear in the manufacturers instructions (I wont be using the torque screwdriver on the N & E bars anyway).

 

[Guitarist]

It's just another way of taking the "skill factor" out of the profession. A good electrician will know when a screw is tight enough (but not too tight), but unfortunately, as with everything nowadays, we have to be told exactly how tight that is. What is more urgent than using a torque driver in my eyes, is getting decent screws fitted to accessories and not the cheap soft ones which shear off when you look at them.

 

[imago]

So does the introduction of set torques mean that manufacturers will have to take greater care with thread machining tolerances? Some of them would exceed the torque simply turning the screw without making contact.

 

[imago]

It's just another way of taking the "skill factor" out of the profession.

I agree, but I think it's experience rather than skill. The longer you spend working on basic hand skills the better you become at judging pressure, torque, distance, plumb etc etc.

I'm not one for flogging the 'apprenticeship only' mantra, but there was a reason we spent so bloody long filing things, cutting threads, bending conduit/cable/tray, cutting stuff back without going into inner sleves, fixing timber batons and so on. Even the ritual toolbox tidying allowed you to familiarise yourself with which 'thingy' did what.

 

[Guitarist]

I agree, but I think it's experience rather than skill. The longer you spend working on basic hand skills the better you become at judging pressure, torque, distance, plumb etc etc.

I'm not one for flogging the 'apprenticeship only' mantra, but there was a reason we spent so bloody long filing things, cutting threads, bending conduit/cable/tray, cutting stuff back without going into inner sleves, fixing timber batons and so on. Even the ritual toolbox tidying allowed you to familiarise yourself with which 'thingy' did what.

Totally agree mate. After a 4 year apprenticeship (supervised by the big boys) I was still learning, but at least I had an idea of the basics. There's no way you can go from being in a job which uses no tools, to using them properly in a matter of weeks. I would consider "skills" as part of being experienced.

 

[imago]

I would consider "skills" as part of being experienced.

Good point, which I think is where a lot of the problem comes with short courses.

You can't teach experience, so there's a huge gap in the total package if you come from a job or background without time on the tools. Equally, you can retrain from some trades and bring those skills and the required experience with you.