The Yamaha Road Star Warrior Forum

I heard a while back the formula for calculating the correct torque when using extensions but I can't remember it. Does anyone know how much you need to increase your torque when you have to use an extension on the torque wrench? I think it has something to do with the added flex between the wrench and the socket. ex: 1 ft# per inch of extension........thanks. I want to be sure I am torquing to the right specs.

I've never heard of extension bars flexing I use the same torque spec even when using extensions. I'd be interested to hear different.

warrior04:

I heard a while back the formula for calculating the correct torque when using extensions but I can't remember it. Does anyone know how much you need to increase your torque when you have to use an extension on the torque wrench? I think it has something to do with the added flex between the wrench and the socket. ex: 1 ft# per inch of extension........thanks. I want to be sure I am torquing to the right specs.

I think that only applies when you're working under a shade tree, or somewhere south of the Mason Dixon line.

I represent that remark! I did not know if that was true or not, I just wanted to be sure....thanks y'all.

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Bladerunr:

I think that only applies when you're working under a shade tree, or somewhere south of the Mason Dixon line.

The torque reference chart that hangs in my backyard reads like this.

1> You tighten that'un yet

2> That'uns tight

3> Way tight

4> Way Fackin tight

5> Who the fack tightened this fuggin thing? Arnold??

6> That fugger's not commin off

and

7> Get the torch!

warrior04:

I heard a while back the formula for calculating the correct torque when using extensions but I can't remember it. Does anyone know how much you need to increase your torque when you have to use an extension on the torque wrench? I think it has something to do with the added flex between the wrench and the socket. ex: 1 ft# per inch of extension........thanks. I want to be sure I am torquing to the right specs.

Using an extension on a torque wrench only REDUCES the force you must apply on the handle in order to generate a given torque. For instance, if you are torquing something to a certain spec, and you add an extension that makes the handle twice as long, then the force you need to apply is reduced by half. Flex in the handle+extension doesn't really enter into it because you are measuring the torque at the head.

Bladerunr:

The torque reference chart that hangs in my backyard reads like this.

1> You tighten that'un yet

2> That'uns tight

3> Way tight

4> Way Fackin tight

5> Who the fack tightened this fuggin thing? Arnold??

6> That fugger's not commin off

and

7> Get the torch!

Are those metric or SAE values?! LOL

SRW

Society of Redneck Wrenchers

Here's a chart http://www.specialpatrolgroup.co.uk/spooky/torque/torque.html if you use a tool like this as an extension adapter http://rswarrior.com/forums/p/20933/325250.aspx#325250 . In the enclosed photo it's being applied at a right angle which doesn't require a multiplier.

Talking with the engineer that works for me he says if you have a 3/8's torque wrench with a 3" extension it will infact increase the amount of ftlbs at the socket. If you have a range of say 50-60 ftlbs set it for the lower limit 50 and you will end up with an increase of a few percent. Of course the longer the extension the more the torque is multiplied.

knyland:

Talking with the engineer that works for me he says if you have a 3/8's torque wrench with a 3" extension it will infact increase the amount of ftlbs at the socket. If you have a range of say 50-60 ftlbs set it for the lower limit 50 and you will end up with an increase of a few percent. Of course the longer the extension the more the torque is multiplied.

• A = length of torque wrench = 15
• B = length of adapter = 5
• C = torque wrench setting to calculate
• D = desired torque at end of extension = 110 ft~lbs

C = 110 (15/15+5) = 82.5

warrior04:

I heard a while back the formula for calculating the correct torque when using extensions but I can't remember it. Does anyone know how much you need to increase your torque when you have to use an extension on the torque wrench? I think it has something to do with the added flex between the wrench and the socket. ex: 1 ft# per inch of extension........thanks. I want to be sure I am torquing to the right specs.

I think people are answering different questions here. Can you describe how/where the extension is being used in your example? Is it used to lengthen the handle or on the head of the wrench? Is it straight off the wrench or at some angle? Without getting too involved in the math, your layout will make a difference in the answer. 

overheadcam427:

I think people are answering different questions here. Can you describe how/where the extension is being used in your example? Is it used to lengthen the handle or on the head of the wrench? Is it straight off the wrench or at some angle? Without getting too involved in the math, your layout will make a difference in the answer. 

I was also under the impression that the subject was toward socket extensions not cheater bars. i hope my guy is right or he has put together alot of main diesel engines and turbines wrong.

knyland:

I was also under the impression that the subject was toward socket extensions not cheater bars. i hope my guy is right or he has put together alot of main diesel engines and turbines wrong.

Socket extensions and cheater bars will have exactly the same effect.