A question about torque screwdrivers

[HappyHippyDad]

I have been umming and arghing about a torque screwdriver for some time but have not yet bought one.

My fears are the following:

1. There are set torque settings that conductors in a consumer unit should adhere to. However, in the neutral bar which are screw terminals I tend to screw a 6mm in tighter than a 1mm (for example), as if you screw in a 1mm too tight it can shear. You can screw in a 6mm pretty much as tight as you can without fear of it going through the copper. I cant see how a torque screwdriver distinguishes between a 1mm and 6mm. Does it? Does it need to?

2. Are torque screwdrivers always accurate? If I use my normal screwdriver I have a 'fairly', if not 'very' precise feel for how tight I have made the connection. This experience will only improve over the years and you will make varying degrees of tightness as required. You lose this with a torque screwdriver and put all your trust in the mechanism.

I wonder if a torque screwdriver may not be a good option for someone who knows how to use a screwdriver properly? However, I am very much open to persuasion hence the post.

 

[telectrix]

Funny, but it's a finger catch, no screwdriver needed.

BUT ARE YOUR FINGERS CALIBRATED?

 

[Mike Johnson]

YES, with Arthritis in my hands I can't put enough pressure on anything anymore let alone torque.

 

[HappyHippyDad]

Well I've just bought the draper torque screwdriver as recommended by one of you chaps.
Easy to put the bit in and it stays in firmly, easy to take out. I know lots of you have said armeg or wiha in another thread but I have ignored your wisdom (maybe to my downfall at a later date) and gone for the draper and I like it, plus I saved £200!!!

It's the first time I've ever used a torque screwdriver. I checked the correct eaton torque settings online and used them accordingly for the MCB's and N/E bars. I would say I very slightly overtigthen the MCB's compared to the torque settings and slightly undertighten 1mm cables in the neutral and earth bar. Pretty much what I expected.

I did find it gave me a degree of comfort or assurance when I heard the click though, still not sure if that reliance is good or bad though .

Thanks everyone for taking the time to respond in this thread.

 

[leebut]

I see what you mean about 'tightening to a particular torque setting'. I guess they must set the Nm to whatever is safe for the 1mm conductor so it does not cause damage to the copper(yet is tight enough), this same torque setting must be the same for the 6mm which means perhaps we over tighten for the 6mm when using a screwdriver. But can you overtighten a 6mm? If I screw the 6mm in as tight as I possibly can I don't see it getting damaged?

one of the major issues I've heard about NOT using a Torque driver is that we do over tighten the screws as we think they need to be locked down tight, this doesn't seem to be the required case as manufacturers are specifying much lower Nm figures which if we were to either under or over tighten the cables in the terminals and an issue occurs its us who come under scrutiny, but if we are to use the said Torque driver and do as the manufacturer states were not to blame, unfortunately there no way we can prove we followed the manurers specification in the first place, but that said if an issue did come to light and you were put under the spotlight by Health and safety, fire investigators or an insurance company etc if you have a Torque driver to show them thats not clean as a whistle from lack of use then you have a better fighting chance than not owning or using one>

I bought the Wiha Torque driver a couple of years back and just tighten all the screws as I'm finishing off to the specified settings and I include a note of the setting values applied to the terminals on my certificate (Belts and Braces done!!)