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.

 

[Midwest]

I see your point about conductor size, but I don't think it has bearing on it, as you are tightening to a particular torque setting.

Torque screwdriver is as accurate as its last calibration, if you buy a decent one.

I only used mine on a CU installation. I was sometimes surprised at the manufactures torque requirements, which makes you wonder, if we do over tighten sometimes.

 

[telectrix]

they are just today's fad. never catch on, same as electric lighting back in the late 19th C, . oops. that one did.

 

[Dustydazzler]

I have a Draper torque and rarely ever use it (I trust me own wrist and experience more than I trust a factory made screwdriver)
I keep it just in case I ever get a situation , where a terminal just doesn't feel right...

 

[MJPD29]

I see your point about conductor size, but I don't think it has bearing on it, as you are tightening to a particular torque setting.

Torque screwdriver is as accurate as its last calibration, if you buy a decent one.

I only used mine on a CU installation. I was sometimes surprised at the manufactures torque requirements, which makes you wonder, if we do over tighten sometimes.

I am the same. I had one particular board where it was around d 1.8nm. I certainly would have tightened it more than that had I been using a normal screwdriver. Made me wonder if the slant in MK or MCG boards etc is from me overtightening. Tried another MCG board and they are in fact cheap dirt as even with the torque setting the slant was unbearable.

 

[Mike Johnson]

1. Most of the better torque screwdrivers are adjustable for settings, you have to do this manually.

2. NO when mine arrived it was way off, and had to be manipulated to bring it somewhere into specification, it still isn't and I have to adjust down from it's settings to obtain the correct torque, It's an Armeg so not a cheap driver.

Trouble is my elbow is way out of calibration due to Arthritis the pain sets in before I reach any type of torque settings and I tend to relax my arm in response.

 

[HappyHippyDad]

I see your point about conductor size, but I don't think it has bearing on it, as you are tightening to a particular torque setting.

Torque screwdriver is as accurate as its last calibration, if you buy a decent one.

I only used mine on a CU installation. I was sometimes surprised at the manufactures torque requirements, which makes you wonder, if we do over tighten sometimes.

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?

 

[telectrix]

if terminating a single 1.0mmin a CU (as is usual with lighting circuits) i always double the end over. this reduces the risk of damaging the conductor. apart fom which. a single 1.0mm conductor in a CU terminal has a chance of not being under the screw, but to one side.

 

[Midwest]

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?

I remember watching one of those IET panel vids, at an Elex Show, for Amendment 3. The Hager bod, said (IHO), overtightening is just a big problem as undertightening, within the industry.

 

[telectrix]

I remember watching one of those IET panel vids, at an Elex Show, for Amendment 3. The Hager bod, said (IHO), overtightening is just a big problem as undertightening, within the industry.

as i came across the other week. meter monkey had sheared the head off one of the terminal screws on the meter Lout. was a right pain getting it out with the juice on.

 

[Midwest]

PS; you do have to factor in the cost of re-calibration, which with most makes is gonna be yearly. When I looked at mine, is was a close call between getting it done, and buying a new one.

 

[Mike Johnson]

When I checked my new ARMEG I hung a 200gram weight off a 1000mm arm set at 2Nm to check it's calibration, I can do that every year and document it.

 

[telectrix]

When I checked my new ARMEG I hung a 200gram weight off a 1000mm arm set at 2Nm to check it's calibration, I can do that every year and document it.

afaik, the only200gram weight i can think of possessing is myleft --------. and i ain't about to hang that on any sort of arm

 

[Julie.]

When I checked my new ARMEG I hung a 200gram weight off a 1000mm arm set at 2Nm to check it's calibration, I can do that every year and document it.

That way you only have to get the 200gm weight and 1000mm rule calibrated instead.

 

[Mike Johnson]

We know a song about that don't we Johny.

 

[telectrix]

That way you only have to get the 200gm weight and 1000mm rule calibrated instead.

thought that was a bloody long rule till i looked it up on a dual tape measure and saw it was only a yard and a bit.

 

[ipf]

they are just today's fad. never catch on, same as DC electric lighting back in the late 19th C, that one didn't either.

....changed that one, tel.
Tesla 1-0 Edison.

 

[ruston]

But it was Tesla 0 in the long run ... They stuffed him.

 

[Mike Johnson]

Oh missis being stuffed when still alive, that smarts.

 

[ipf]

But it was Tesla 0 in the long run ... They stuffed him.

Yeah...and used plenty of his genius ideas to their gain...
If only he'd gone to Manchester instead of NY.

 

[ruston]

Yeah...and used plenty of his genius ideas to their gain...
If only he'd gone to Manchester instead of NY.

He should of teamed up with Lord Armstrong. Bit of an age difference , but who cares.

 

[ipf]

He should of teamed up with Lord Armstrong. Bit of an age difference , but who cares.

Too true, with Tyneside manufacturing. I'm just thinking of the possibilities for industry around these parts but we could have been years ahead in all sorts of fields. Mind you, there were always money men to cut the futuristic down to size.

 

[ruston]

Too true, with Tyneside manufacturing. I'm just thinking of the possibilities for industry around these parts but we could have been years ahead in all sorts of fields. Mind you, there were always money men to cut the futuristic down to size.

That's what basically happened to Tesla. Armstrong was a bit more pragmatic.
We did Ok though with leading the world with inventions during the Victorian era.
Armstrong was ahead of his times with his views. Here is a cut from Wikepedia.

Armstrong advocated the use of renewable energy. Stating that coal "was used wastefully and extravagantly in all its applications", he predicted in 1863 that Britain would cease to produce coal within two centuries.[4] As well as advocating the use of hydroelectricity, he also supported solar power, stating that the amount of solar energy received by an area of 1 acre (4,000 m2) in the tropics would "exert the amazing power of 4,000 horses acting for nearly nine hours every day".[13]

 

[HappyHippyDad]

as i came across the other week. meter monkey had sheared the head off one of the terminal screws on the meter Lout. was a right pain getting it out with the juice on.

How did you?

 

[Julie.]

How did you?

Carefully?

Plus some more words

 

[DPG]

We know a song about that don't we Johny.

Hale and Pace. Brill.

 

[telectrix]

How did you?

1 side of the screw was left, but other side of slot gone. careful use of sidecutters to break lock, then screwed out with long-nose pliers.

 

[Megawatt]

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.

Happy in the US in the 2020 NEC edition we have adopted that all that terminations be torqued to the manufacture ins-trucking and pass inspection by code enforcement

 

[HappyHippyDad]

One last thing about this..

Do you have to send off your screwdriver to be calibrated or can you buy some sort of calibrating tool to do it yourself?

 

[telectrix]

i calibrate mine . if it clicks, it works.

can just imagine Fuzz Towshend saying " i can't refit this cylinder head in time as my torque wrench is away for calibration".

 

[Midwest]

One last thing about this..

Do you have to send off your screwdriver to be calibrated or can you buy some sort of calibrating tool to do it yourself?

There's various online places, that'll be willing to take your hard earned cash. Personally I would overly worry, until there's some mandatory or requirement thing, like with MFT's & Schemes.

Perhaps once in a while, but then I'd probably buy a new, and sell the old one to someone on here

 

[Megawatt]

One last thing about this..

Do you have to send off your screwdriver to be calibrated or can you buy some sort of calibrating tool to do it yourself?

I guess send it of probably once a year I haven’t found one yet

 

[Andy78]

One last thing about this..

Do you have to send off your screwdriver to be calibrated or can you buy some sort of calibrating tool to do it yourself?

If you go for Wiha you can buy this .....

View: https://www.youtube.com/watch?v=kKqw24JQdD4

 

[Mike Johnson]

How do you get the calibration tool calibrated? . A snip at £130.00.
[automerge]1583705818[/automerge]
Anyone have one of the torque check device's and can confirm what driver is needed to use it, I know it comes with them, but wanted to know if it can be used with other torque drivers.
[automerge]1583705974[/automerge]
Looks like an Allen key on the end, and also looks as though it only checks at 2.8Nm.

 

[Mike Johnson]

Or we could club together and buy one of these: Mecmesin | Torque screwdriver check calibrator - https://www.mecmesin.com/software-controlled-torque-systems/torque-screwdriver-check-calibrator I have no idea how much one would cost, but I assume it would not be cheap.

 

[Megawatt]

Or we could club together and buy one of these: Mecmesin | Torque screwdriver check calibrator - https://www.mecmesin.com/software-controlled-torque-systems/torque-screwdriver-check-calibrator I have no idea how much one would cost, but I assume it would not be cheap.

I found one that they use to work on firearms and it’s the cheapest yet

 

[billyblade]

The standard that torque screwdrivers are manufactured to (EN ISO 6789:2017) states that the first re-calibration should be carried out 12 months after first use or 5000 actuations (whichever comes first). How many people are going to actually count how many times it has clicked and document it? So 12 months it is.

Anyone who has their torque equipment inspected should be able to produce a valid calibration certificate to prove the calibration has been carried out to the standard quoted above. If they can't, then in theory the torque screwdriver is not being used correctly.

The reason people use one is to prove that they've done everything in their power to install to a manufacturers recommendations with regard to terminal torque settings.

There are many accredited companies around who can calibrate torque equipment. Some of the meter calibration companies have started doing it now too.

It can prove to be quite expensive when you consider the actual cost of the calibration check coupled with possible carriage costs. That's before you take into account the potential for maybe paying for an adjustment too. Many people have said they may as well buy a new torque screwdriver handle instead.

A check tool is a peace of mind thing really. Just to satisfy yourself that your handle is doing what you think it should be. Only a valid calibration certificate will satisfy the standard though.

If you buy a new torque screwdriver most of the time the calibration certificate will appear to be out of date. There are many factors that influence this including time from factory to warehouse, time from warehouse to wholesaler, shelf time at the wholesaler. As I said the first re-calibration should be carried out 12 months after the first use. The date of the first use can be taken as day of purchase (as it can't have been used before then, also assuming that it hasn't been purchased second hand) so therefore if you keep your purchase invoice with the original certificate this should satisfy any inspection and the date on the invoice should be taken as proof of the first possible use, not the date on the original calibration certificate.

Lastly, good working practice should lead you to wind the handle down to its lowest setting when not in use. This releases the tension from the spring mechanism inside and reduces the risk of having to have an adjustment carried out at calibration (if indeed the handle is able to be adjusted).

 

[Mike Johnson]

So who writes the certificate of calibration if you have the Wiha self test unit, are testing certificates available for you to fill them out yourself?

 

[telectrix]

if CU designers were that fussy about torque settings, then they should at least make the terminals so that they didn't cam out before specified torque is reached.

 

[ruston]

if CU designers were that fussy about torque settings, then they should at least make the terminals so that they didn't cam out before specified torque is reached.

This is the problem with low torques, it is not so bad on new equipment, but a bit of crud on old fittings can influence a low torque.

 

[billyblade]

So who writes the certificate of calibration if you have the Wiha self test unit, are testing certificates available for you to fill them out yourself?

It's a torque checker, not a calibration tool. It doesn't really measure and record readings rather it indicates that the torque screwdriver is working correctly. It does not remove the need for annual calibration

Green light for safety – check the functionality of torque tools every day with Wiha Torque QuickCheck

It’s a familiar situation for users. After the recommended period of one year or 5,000 couplings, it’s time to send the torque tool off for…

www.wiha.com

To produce a calibration certificate you need to follow EN ISO6789:2017. There are extensive checks stipulated (including 5 checks at 3 separate settings with the average values recorded).

 

[davesparks]

One last thing about this..

Do you have to send off your screwdriver to be calibrated or can you buy some sort of calibrating tool to do it yourself?

The proper use, care and calibration of precision torque screwdrivers and wrenches is not as simple as it is for test gear.
Ultimately it relies on a precision spring to get the actual torque setting.

Some key points are having the torque device at the correct temperature, always returning it to its minimum setting for storage, operating it a few times before use if it hasn't been used for a while.
Calibration periods are often set by the number of operations rather than by time period.

Any application where torque is actually critical will already be subject to significant checking and monitoring with ever use of the torque device being properly logged against each specific fastener it is used on.

 

[telectrix]

but don't any of you think this is all overkill. next we'll see plumbers having temp.calibrated blowlamps to stop them burning structures, and wood butchers with their hammers calibrated in foot pounds in case they nail a plumber to the floor too tightly..

 

[Moley]

Any application where torque is actually critical will already be subject to significant checking and monitoring with ever use of the torque device being properly logged against each specific fastener it is used on.

We have to go through that on some our jobs. Usually the reconnection on gen transformers or the connections on the main generator breaker. Very often we have the site engineer watching the torquing and noting down the readings against each braid or connection. Some check the torque setting on the wrench at the start and finish of the reconnecting to make sure it hasn't changed. Then comes the ductoring....

 

[Midwest]

On a domestic setting ( see what I did there), who will actually be asking for you to provide a calibration certificate, for your torque screwdriver?

 

[Moley]

In a domestic situation I really don't see the need for torquing (hmmm.. spell checker wanted to change that to torturing). Anyone who has been in this game should be able to work out if a screw is tight.

 

[davesparks]

I don't believe the terminals are of a good enough quality these days to achieve a properly torqued question.

 

[pc1966]

From my own (limited) experience of torque screwdrivers I found the recommended setting for some of the bigger screws sort of matched my hand-experience setting, and for some of the smaller screws it was about 1/8 to 1/4 turn more than I would normally do, but not a massive difference.

I think the major advantage is to reduce seriously wrong values for folk without a lot of experience (or for unusual devices) and for that precise calibration is not needed, just a sanity check on its functionality. Of course, one you get in to insurance/liability/etc then you might find it becomes another routine expense to have provable current calibration certificates for torque tools.

 

[Midwest]

Ommph. I'm out.

 

[ipf]

Anybody use 'em for fixing back boxes??????