Do I need a torque screwdriver set?

Steady Steve · Jan 11, 2022

I've just started my training and am interested in what tools are essential when first starting out. Is the torque screwdriver regarded as one of the useful tools in the toolbag? Thanks

MJPD29 · Jan 11, 2022

No probably not.I had one for 3 years and used it twice, then sold it. For some specialist applications then torque tools are required but for the majority of the work I do I'm comfortable I've tightened stuff correctly with a normal screwdriver

nicebutdim · Jan 11, 2022

If you're starting to gather up tools, I wouldn't be too concerned about a torque screwdriver just yet.

Pliers, shears, side cutters, screwdrivers would be the basics to start with, then increase that range of hand tools depending on what sort of work you find yourself doing. Maybe add a pair of 8" grips to the list of essential tools - I hate them, but have to conceed they cover a lot of uses.

Steady Steve · Jan 11, 2022

Matthewd29 said:
No probably not.I had one for 3 years and used it twice, then sold it. For some specialist applications then torque tools are required but for the majority of the work I do I'm comfortable I've tightened stuff correctly with a normal screwdriver

That's good to know. There seem to be so many tools available - of varying specialisation - that I only want to look at those that are necessary. A cable stripper is something that I did recently purchase.

Steady Steve · Jan 11, 2022

nicebutdim said:
If you're starting to gather up tools, I wouldn't be too concerned about a torque screwdriver just yet.

Pliers, shears, side cutters, screwdrivers would be the basics to start with, then increase that range of hand tools depending on what sort of work you find yourself doing. Maybe add a pair of 8" grips to the list of essential tools - I hate them, but have to conceed they cover a lot of uses.

Thanks, now that's a very reasonable list!

littlespark · Jan 11, 2022

The only thing where a torque driver would need to be used is a consumer unit, where there is a Nm value stated for tightening terminals.
If your just starting out, you won’t be doing many of them.

It is argued that too tight can be as bad as too loose, but as you progress, you’ll get a sixth sense with a manual driver whether it’s too tight or loose….

But then, your “tight enough” may be 2Nm, or 3Nm where the stated is 2.5.

timhoward · Jan 11, 2022

I'd have a a couple of "PlusMinus" screwdrivers for consumer units much higher up the list than a torque one.

Steady Steve · Jan 12, 2022

littlespark said:
The only thing where a torque driver would need to be used is a consumer unit, where there is a Nm value stated for tightening terminals.
If your just starting out, you won’t be doing many of them.

It is argued that too tight can be as bad as too loose, but as you progress, you’ll get a sixth sense with a manual driver whether it’s too tight or loose….

But then, your “tight enough” may be 2Nm, or 3Nm where the stated is 2.5.

That's useful to know. I should have tightened a few terminals by the time my training takes me to consumer units.

Steady Steve · Jan 12, 2022

timhoward said:
I'd have a a couple of "PlusMinus" screwdrivers for consumer units much higher up the list than a torque one.

I'm glad that having a torque is not obligatory, and so I'll focus on having a couple of plus minus - I've heard it before and it makes sense now.

telectrix · Jan 12, 2022

Steady Steve said:
I'm glad that having a torque is not obligatory, and so I'll focus on having a couple of plus minus - I've heard it before and it makes sense now.

might have a couple of +/- spare. if i can find them you can have them cheap. I'm just outsideof Northwich, so easy pick upif I have them.

SJD · Jan 12, 2022

You might not need a torque screwdriver for day to day use, but I'd suggest you need one in your toolbox once you are completing jobs like consumer unit changes. So that you have the means to tighten terminals to manufacturer's specifications, even if you think you can do it accurately enough without.

Years ago, my college tutor told us of a court case, where an electrican was asked about the content of his toolbox, and it didn't include a torque screwdriver. He was then asked how me managed to tighten the terminals to the correct values. He had no defence. Don't recall the rest of the details (I think something caught fire).

pc1966 · Jan 12, 2022

The only +/- ones I have are bits for my torque screwdriver!

But they do make a difference as often the screw heads are easy to damage at higher torques, even if to begin with you are just given the job of dismantling stuff so unscrewing a tight fastener.

For many years the skill of sensibly tightening terminals was something that was learned as an apprentice, etc, so you could reliably make connections that would not undo with vibration or thermal cycling, as well as not leading to damage to the wire and/or cable clamp itself. But with the number of botched installations presenting a fire risk the industry has moved towards the use of torque tools to try and reduce dependency on such skill and to help get better control over results.

Also a torque set is quite a handy way to get a feel for what is correct for 2Nm, etc, but you can probably borrow one for such a trial.

That is much the same as garages have been for last 50+ years, most bolts/nuts are done by hand, but critical ones like cylinder head, water pump, driveshaft, etc, finished with a torque wrench.

Another factor is stuff being poorly done and often damaged on assembly is monkeys using an impact wrench. Except for some very specific tools, NEVER use a power tool on electrical terminals! Most impact drivers will, even at the lowest setting, hammer the faster home to a much higher torque that most can cope with. Typically the only ones likely to survive are going to be M8 or larger studs, etc. A moment's carelessness with my own impact driver (Milwaukee M18FID2) resulted in me shearing a M6 roofing screw when assembling cable try, so I am not joking!

Having said that, my impact driver is a most excellent tool to have (though not the cheapest) for drilling with the hex-shank bits, using the 20mm - 32mm hole saws for glands, etc, and for mechanical assembly/disassembly on larger wood screws or bolts as it really gets the job done quickly.

TL;DR Concentrate on basic hand tools first (as @nicebutdim said), then look at some useful power tools for mechanical work and as you get to assembly CU or other stuff with high current terminals then look at a torque set.

pc1966 · Jan 12, 2022

SJD said:
You might not need a torque screwdriver for day to day use, but I'd suggest you need one in your toolbox once you are completing jobs like consumer unit changes. So that you have the means to tighten terminals to manufacturer's specifications, even if you think you can do it accurately enough without.

Years ago, my college tutor told us of a court case, where an electrician was asked about the content of his toolbox, and it didn't include a torque screwdriver. He was then asked how me managed to tighten the terminals to the correct values. He had no defence. Don't recall the rest of the details (I think something caught fire).

Very good point!

timhoward · Jan 12, 2022

I really shouldn't admit this...but for several years I had something rather like this, picked up for about a tenner. Intended for bicycle use.
Obviously NOT insulated and lethal if not concentrating, but it indicated 2-10nm and got me by. (Some screws are less than 2nm on some consumer units, especially on earth and neutral bars.)

[ElectriciansForums.net] Do I need a torque screwdriver set?

When I mislaid about 5 years ago I finally bought a proper Armeg set.

There is a modern bike tool that does 1-8nm and costs £39 but that is getting too close to the Toolstation £64 Draper 1-5nm VDE offering to be worth scrimping on.
So don't do what I did!

Rockingit · Jan 12, 2022

pc1966 said:
Another factor is stuff being poorly done and often damaged on assembly is monkeys using an impact wrench. Except for some very specific tools, NEVER use a power tool on electrical terminals! Most impact drivers will, even at the lowest setting, hammer the faster home to a much higher torque that most can cope with. Typically the only ones likely to survive are going to be M8 or larger studs, etc. A moment's carelessness with my own impact driver (Milwaukee M18FID2) resulted in me shearing a M6 roofing screw when assembling cable try, so I am not joking!

Having said that, my impact driver is a most excellent tool to have (though not the cheapest) for drilling with the hex-shank bits, using the 20mm - 32mm hole saws for glands, etc, and for mechanical assembly/disassembly on larger wood screws or bolts as it really gets the job done quickly.

I have an impact WRENCH (1/2") that I use constantly for deep socket 15/17/19mm work in generator busbar chambers, turns a 2m job into a 1s one - however - it's a Makita one with clever adjustable modes, so it's set so that as soon as it starts to actually impact it shuts off automatically so that you have more control over the final few 1/4 turns. Likewise it senses when the nut is loose and stops spinning so that you don't end up with it flying off. But I can't think that I've ever used a motorised tool on a standard terminal screw, or fixing plate, EVER in my now 34 years of sparkying. As the old saying goes.... "It's only fun until someone (or thing!) gets hurt"

pc1966 · Jan 12, 2022

timhoward said:
There is a modern bike tool that does 1-8nm and costs £39 but that is getting too close to the Toolstation £64 Draper 1-5nm VDE offering to be worth scrimping on.
So don't do what I did!

I have a selection of torque wrenches and screwdriver-like drivers for mechanical work and so I use them when needed for big terminals.

It makes me very uncomfortable, even when I have done the safe isolation and double checked everything, to be gripping such a large metal object that is now going on to a normally live terminal! Usually I make sure I'm not in contact with anything else, one time I donned my 1kV "you have been Tangoed" gloves as a precaution.

If I did more of that as a profession then I would spend the ~£1k on a VDE socket set and matching torque wrench(s) but as I have only needed to do so a few times in the last year or two I didn't.

pc1966 · Jan 12, 2022

Rockingit said:
I have an impact WRENCH (1/2") that I use constantly for deep socket 15/17/19mm work in generator busbar chambers, turns a 2m job into a 1s one

Makes sense when the tool is able to deliver the torque control needed for the job.

Other than one special (and quite expensive) driver that was intended for speedy screw terminal work I really can't abide such tools used on screw terminals though. Was it Whia that made it? Cost about £300

My Milwaukee conventional battery power drill fails on this front as the torque control is not a mechanical adjustable slip-coupler but appears to be electronic motor control. What they seem to have overlooked is the equivalent inertia of a geared-down motor, it still tries to wrench itself from my hand when it jams, etc

Found it £282 inc VAT:

https://cpc.farnell.com/wiha/42267/screwdriver-speede-set-2-uk-spec/dp/TL19981?MER=sy-me-pd-mi-alte

Rockingit · Jan 12, 2022

pc1966 said:
Found it £282 inc VAT:

https://cpc.farnell.com/wiha/42267/screwdriver-speede-set-2-uk-spec/dp/TL19981?MER=sy-me-pd-mi-alte

There again...... it IS my birthday in a couple of days......

pc1966 · Jan 12, 2022

I just checked the spec for my hex impact wrench:

Mode 1 : 119 Nm / 0 - 1,900 rpm / 0 - 1,200 ipm
Mode 2 : 176 Nm / 0 - 2,800 rpm / 0 - 3,400 ipm
Mode 3 : 226 Nm / 0 - 3,600 rpm / 0 - 4,300 ipm
Mode 4 : Self-tapping / faster installation time by reducing stripping of fasteners.

So it is pretty obvious why I was able to trash an M6 steel screw with it!

They also do a quieter hydraulic version, about £100 more, but its spec is 40Nm so while stupidly high by electrical terminal work, more reasonable.

From memory a typical M8 high tensile (8.8) bolt/nut is around 30Nm but for electrical use with lower strength materials probably half that.

Dustydazzler · Jan 12, 2022

Most 'electricians' these days use an 18v impact to do consumer units , in fact the 18v impact seems to be used for pretty much everything

pc1966 · Jan 12, 2022

Dustydazzler said:
Most 'electricians' these days use an 18v impact to do consumer units , in fact the 18v impact seems to be used for pretty much everything

Ah, you mean the YouTube attentionwhores ?

Petej999 · Jan 12, 2022

Dustydazzler said:
Most 'electricians' these days use an 18v impact to do consumer units , in fact the 18v impact seems to be used for pretty much everything

If you are a cowboy electrician !!!!

Rockingit · Jan 12, 2022

Petej999 said:
If you are a cowboy electrician !!!!

Way back a few years ago we had really bad 'proper' snow down here and nobody could get anywhere as it's all small roads that get gritted last, I had some housecalls to do, just 10 min maintenance type stuff and I seriously considered riding out on my then step-daughters horse to go and get to them, thought it would be a nice novelty piece for the local rag - 'the electrician that always delivers no matter what' kind of nonsense. Then all the Cowboy Electrician potential jokes occurred to me so I refrained!!

LewisM · Jan 12, 2022

You'd have to really give it some with a screwdriver to damage a MCB or cable so a torque screwdriver I think is not worth the money but if you're doing anything that requires things like spanners, ratchets, hex keys etc then I'd use torque wrench or similar as it's very easy to overtighten fasteners/terminals as you have much more leverage and force

Rockingit · Jan 12, 2022

LewisM said:
You'd have to really give it some with a screwdriver to damage a MCB

Not so sure I'm with you on that one - a pet hate is when the casing wants to split on a device terminal when you actually properly tighten it, even by hand