Does an extension affect a torque wrench?

[FLORIT]

OK, all you mechanics (and physics majors) out there. Does putting an extension on a torque wrench affect how it measures torque? We all know adding an extension to our ratchet allows us to apply more force with less effort. But when I put that extension on the torque wrench, am I screwing up its calibration?

My instinct tells me "no", but I would like some expert opinion. Thanks.

[gangster1]

Yes. To what degree I'm not sure.

[mdgto]

No it shouldn't. The tourque is measured down at the head of the wrench. It doesn't matter how the force is applied to the handle.

[DANSLS1]

Are you putting an extension like a 4" long 3/8" to 3/8" adaptor extension needed to install plugs, or like an extension to the handle to get extra force? If the answer is a, then no - not appreciably. There will be a slight loss because of the play in the extension - but nothing that will affect you more than the standard gage variance. b - in and of itself, using an 'extension bar' will not affect the calibration of the gage - but may cause you to overtorque something easier and could affect long term usage.
Dan

[GTOdriver7]

Are you putting an extension like a 4" long 3/8" to 3/8" adaptor extension needed to install plugs, or like an extension to the handle to get extra force? If the answer is a, then no - not appreciably. There will be a slight loss because of the play in the extension - but nothing that will affect you more than the standard gage variance. b - in and of itself, using an 'extension bar' will not affect the calibration of the gage - but may cause you to overtorque something easier and could affect long term usage.
Dan

im a mechanical engineer. and i agree

[DANSLS1]

Chemical here, by degree - but I work in the fastener industry - ;)

[mistermike]

Extension will allow you to reach the same torque with less effort.

[FLORIT]

Are you putting an extension like a 4" long 3/8" to 3/8" adaptor extension needed to install plugs, or like an extension to the handle to get extra force?

Yes, I'm talking about Option A... an extension from the head to the socket. Anything that needs Option B, a "breaker bar" to apply torque I'm gonna let the mechanics handle. BTW, changing the plugs on the GTO was so easy even *I* could do it! :D

[cjlannoy]

Chemical here, by degree - but I work in the fastener industry - ;)
I'm also a chem eng. :)

[AmesGTO]

I'm a Computer E. Does that mean GM is hitting their target audience?

[mistermike]

I'm a Computer E. Does that mean GM is hitting their target audience?It would if I weren't a men's room attendant. That should counteract at least 3 or 4 doctors or engineers. Sorry GM. :drink:

[FLORIT]

I don't know what GM's target market really was. The age demographic poll shows 50% of current owners are between 30 and 49 years old. If we were serious about statistical analysis we could expand the survey to include all sorts of variables, such as geographic location, job title, income, sex (or lack of), etc.

One "variable" seems to really be a "constant". We all LOVE our new GTO's. :D

[1stChildhood]

OK, all you mechanics (and physics majors) out there. Does putting an extension on a torque wrench affect how it measures torque? We all know adding an extension to our ratchet allows us to apply more force with less effort. But when I put that extension on the torque wrench, am I screwing up its calibration?

My instinct tells me "no", but I would like some expert opinion. Thanks.

mistermike and others are correct--longer handle such as a pipe will require less force by your hand. If you double the handle length, the force required to reach a given torque value will be halved (T = F x R) . The torque is measured at the head either by the long pointer mounted there when the handle deflects, or other mechanism. So just take the reading as usual. However I would imagine the wrench maker would frown highly on the practice.
B.S. Physics, M.Ed. Physics, Not a Mechanic. I Defer to all Mechanics Unless they are Wrong. :D

[1stChildhood]

mistermike and others are correct--longer handle such as a pipe will require less force by your hand. If you double the handle length, the force required to reach a given torque value will be halved (T = F x R) . The torque is measured at the head either by the long pointer mounted there when the handle deflects, or other mechanism. So just take the reading as usual. However I would imagine the wrench maker would frown highly on the practice.
B.S. Physics, M.Ed. Physics, Not a Mechanic. I Defer to all Mechanics Unless they are Wrong. :D

Guess he meant socket extension-- right, no change, no problem--the torque is transferred laterally so no effect, providing the extension's not so long that things start flexing off the intended axis.

[mistermike]

Guess he meant socket extension-- right, no change, no problem--the torque is transferred laterally so no effect, providing the extension's not so long that things start flexing off the intended axis.
Does that mean I have to stop using my latex socket extensions? :D

[DANSLS1]

Does that mean I have to stop using my latex socket extensions? :D


I think the appropriate response is that you can do whatever you want w/ latex - just don't tell us about it please! ;) :)

[Old Goat]

Adding a vertical extension to the head, no problem, as everyone has said. Adding a horizontal extension to the handle, no problem, as everyone has also said. Just watch the gauge carefully. On the other hand, if you add any horizontal extension to the head end, you will have a problem. It will throw your reading off. I am talking about a crow's foot or similar device. To avoid having to deal with this and go look up the formula, I learned to position any horizontal extension at the head end of the wrench at 90* in relation to the handle. The effect cancels out. Just something I remember from my Navy days, and my brainy flash for the day. Now I have to go back to the freaking form 1040. You folks think I can get away with deducting the Goat as a monkey business expense on form 2106?
;)

[gto_in_nc]

mistermike and others are correct--longer handle such as a pipe will require less force by your hand. If you double the handle length, the force required to reach a given torque value will be halved (T = F x R) . The torque is measured at the head either by the long pointer mounted there when the handle deflects, or other mechanism. So just take the reading as usual. However I would imagine the wrench maker would frown highly on the practice.
B.S. Physics, M.Ed. Physics, Not a Mechanic. I Defer to all Mechanics Unless they are Wrong. :D

Funny where physicists turn up, isn't it? I think the target market (whether intentional or not) is very interesting in its mix. Oh yeah! B.S. Applied Physics (dropped out of PHY grad school when wife had "other plans" - he's 10 now), MBA

BTW, your view of mechanics is right on the money and applies equally well to engineers as well.

Oh! Almost forgot! Yep, they're all correct... ;)

[GTA91]

Well, I'm a Manufacturing Engineer (quality) and I say no as well.


BTW- my dad's a mechanic and I turn alot of wrenches on the side. I think GM hit their target as well!