Torque Wrench

[trlong]

<font color="blue"> </font><font color="blue" class="small">( ok,i see i have opened up a can of worms here,,,,,,,,,,,,,,,just for kicks and giggles,.......i hope this clears things up a bit ,,,,,,,,,,,,,,,,,,,,,,, )</font> </font>

To really clear things up, wouldn't it be nice if we could actually join the rest of the world and go SI? My limited brain cells find it much easier to deal with kg, N, m, etc., and move decimal places rather than divide everything by multiples of two and/or convert from decimal to fractions. Ofcourse, fractions are exact (but only on paper). /forums/images/graemlins/tongue.gif

 

[TMcD_in_MI]

</font><font color="blue" class="small">( it's actually simple physics. length + diameter determines necessary force.

i hope this clears things up a bit ,,,,,,,,,,,,,,,,,,,,,,, )</font>

Sorry, but I don't believe it does/forums/images/graemlins/confused.gif. Adding an extension, no matter how long, doesn't change the length of the lever arm, so it can't change the torque value. In your example, I'm not sure what diameter you're referring to.

txhawg already did a perfect job of analyzing the situation, so I'm going to just shut up now. /forums/images/graemlins/laugh.gif

Regards

Tom

 

[Chillimau]

BillyP, I totally agree with your statement.

However, We haven't changed torque wrenches. To get 500lbs of torque on the bolt we set our 12" torque wrench to 500lbs. If we added a 12" offset such as a crows foot to our 12" torque wrench we now have an effective length of 24". So to get the same 500lbs of torque we need to set the torque wrench to 250lbs. If we leave the 12" torque wrench set at 500lbs with the 12" crowfoot we will apply 1000lbs of torque to the bolt.

We are saying the same thing that a longer lever makes it easier on you, but I'm using the same Torque Wrench in both cases.

TXHAWG, right on the money!! Excellent! That formula should come with every torque wrench sold.

STEF, Good point...It is harder to support the pivot point when you start adding extensions and makes in harder for the user because of that. I agree.

Cheyenne , Thank you.

GBick, I agree attaching at 90 degrees wouldn't change the effective torque, but best I can figure that is a useless position for a crows foot. I'm not trying to be rude, probably seems that way, just stating my limited understanding of mechanical things. Best I can see it, you would have the torque wrench out of the plane of rotation with a crows foot attached at 90 degress.

RB4410, doesn't clear anything up. Now you are talking about clamping force requirements and the selecting the proper fastener to meet those requirments. We aren't designing the connection that has already been done. Shoot, we can't even agree on how to torque it let alone how to design it.

The only thing I agree with is that it is harder to use an extension with a torque wrench (or breaker bar or rachett) like Stef stated. It takes two hands. You must support the pivot point with one hand and apply the force with the other hand to get the correct torque applied. Doesn't change the amount torque needed, only makes it more difficult to apply it.

Disclaimer: This post is not intended to upset anybody and I apologize if it does.

 

[Cheyenne]

Your last sentence is correct---you were.

 

[trlong]

<font color="blue"> </font><font color="blue" class="small">( Your last sentence is correct---you were. )</font></font>

Hope it was taken in the spirit intended (lightening up how deep a simple question led us). If not, I apologize.