# Torque to me...



## Trimix-leccy (Dec 4, 2007)

Bit of a dilema here, so bear with me please

I have a lot of M10s and M12s to 'Torque up' on my latest project [1000KVA 415V service upgrade for a server farm]

Most of the bolts are accessible and can be done with the torque wrench and appropriate socket in the usual fashion. Problem is that some cannot be reached with a socket and I will have to use a 'crows foot wrench' in place of the socket. So my question is...assuming that I use the setup as a 'torque spanner' [cannot think of a better description] will this appreciably alter the torque settings as the centre line axis of the bolt head will now be offset/extended out from the original axis of the socket by some 25mm...if you see what I mean???

Or should I try to post some pics tomorrow


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## BryanMD (Dec 31, 2007)

Leverage.
There are all sorts of tables on the 'net with detail for allowances using other than straight thru leverage with a torque wrench. Some will even speak British. 

Meeting Mum for dinner in 20 or I'd have googled


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## Trimix-leccy (Dec 4, 2007)

Problem solved

Found Norbars site and they have a torque converter program on it.

I have also realised that if I set the crows foot at 90 degrees to the axis line of the handle then there should be no appreciable change to the applied torque


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## John (Jan 22, 2007)

Trimix-leccy said:


> Problem solved
> 
> 
> I have also realised that if I set the crows foot at 90 degrees to the axis line of the handle then there should be no appreciable change to the applied torque


It will still make a difference, you still need to take into account the 25 mm of the crows foot wrench attached to the torque wrench. At 90 Degrees the length will be hypotenuse equal to “h”, the length of the crows foot wrench = “C2’ and the length of the torque wrench = “C1” 


View attachment 512


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## Ecopat (Apr 17, 2008)

Wow, you are good.


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## Trimix-leccy (Dec 4, 2007)

John said:


> It will still make a difference, you still need to take into account the 25 mm of the crows foot wrench attached to the torque wrench. At 90 Degrees the length will be hypotenuse equal to “h”, the length of the crows foot wrench = “C2’ and the length of the torque wrench = “C1”
> 
> 
> View attachment 512


I had thought of that but the difference will be so small that I thought it acceptable; I was just going to aim at the lower end of the recomended settings.
The alternative was to torque them up to 'grunt tight':whistling2:...but I felt the 90 degree option to be better:thumbsup:


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## chrisb271 (Jul 6, 2007)

I tend to prefer the latter method trimy.

A grunt and a trump and alls well ! :laughing:

Whatever happened to good old pounds per square inch its all modern stuff now like Newton sh!tty metres :no:


Chris


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## Trimix-leccy (Dec 4, 2007)

chrisb271 said:


> I tend to prefer the latter method trimy.
> 
> A grunt and a trump and alls well ! :laughing:
> 
> ...


Laser levels as well, everything has a bl00dy laser on it! Just bought a cheap chop saw and a jigsaw [home use]. Both with lasers...both useless. As soon as you do the first cut the laser clogs with dust and you can't see it:laughing:

_*'Rack o't eye and twist o't gob'*_ works better, is cordless, is VDE approved and works on black coffee....also it never gets left in the van:laughing:


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## John (Jan 22, 2007)

FYI (god I hate this acronym) Here is a link to a line of shear nuts and shear bolts that are designed to apply a permanent one time torque.

http://www.insight-security.com/ssf-shearnuts.htm


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## Trimix-leccy (Dec 4, 2007)

John said:


> FYI (god I hate this acronym) Here is a link to a line of shear nuts and shear bolts that are designed to apply a permanent one time torque.
> 
> http://www.insight-security.com/ssf-shearnuts.htm


Thanks for that.

Problem is that I need to keep the installation 'original' so there is no _comeback_ on me. So I need to use the original fixings that came with the kit.

The MCCBs [Merlin Gerin] all come with plastic shear nuts for connection to the Busbars...brilliant. Issue I have is the only kit which is not MG is 2 SOCOMEC 630A 415v Changeover switches to isolate and bypass the AMF panel in case it all goes horribly wrong. It went nasty in a similar site previously when the AMF panel went up in flames and there was no way to take it off line as the isolators were integral to the AMF panel. Fire due to lose connection on manufacturers side


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