Torque Wrench Tool Calculation

Click For Summary
The discussion centers around the calculation of torque when using a torque wrench with an extender bar. The correct method involves multiplying the force applied at the handle by the total length of the wrench and extender, while a flawed alternative incorrectly simplifies torque calculations by misapplying the concept of effective length. The confusion arises from treating torque as a direct multiplication of force and distance without considering the physical lengths involved. Participants clarify that torque is defined as force times distance, emphasizing that the torque wrench's length must be accounted for in calculations. Ultimately, the conversation highlights the importance of understanding the mechanics behind torque application to avoid miscalculations.
  • #31
Drakkith said:
Nearly all of Post #24 (Your post) is unnecessary criticism of everyone else in this thread. That makes everyone less likely to be interested in whatever else you may have to say.

I do hope you understand now however. Is there anything else we can help you with?

"Is there anything else we can help you with?" No, not really. BTW, the "we" in that sentence makes sounds like you surely must be the forum moderator. If not, maybe the word should have been "I"?

My post #24 was merely admission that we seemed to be done. There was no criticism intended whatsoever -- but exasperation certainly was evident. I tried to summarize, said thanks to all, and then tried to bring this to an end courteously. If you'll read between the lines, you may understand that post #24 was also prompted by the "boring thread" and "moderator intervention" comment. That, and the realization that though I kept asking for us not to rehash the correct calculation method, we seemed to keep doing so over and over again. From my POV, only xxChrisxx's recent post really got to the heart of the matter, but that came after a lot of wheel spinning.

Enough of this conversing about conversing. Again, thanks to those who genuinely tried to help. I do now (and did) understand torque, but more importantly in this case, the true problem with the known wrong "simplified" calculation is clear. Good!
 
Physics news on Phys.org
  • #32
xxChrisxx said:
I'm a he :D. I'm also not a teacher, which is why I sometimes make a total mess of explaining things.

The method doesn't work becuase it's just incomplete. If you define the moment, you can then solve it. This led you to the following conclusion:



Do you now see that in this case, you were acutally defining the moment applied to the whrech in terms of a force and a distance? Inadvertently creating a 'second wrench'.

Do you also now see why you would acutally get 300 ft-lb at the socket in the second case?

No, not at all, I thought your post was quite clear. Thanks for submitting it.

Regarding your "second wrench" comment, I like that way of putting it much less than your earlier elegant post. What has always been obvious is that merely trying to look only at the torque applied by the wrench is doomed to fail since this leads to an infinite family of lengths and forces, all of which produce that same torque at the wrench, but an infinite number of torque answers at the end of the extender.

Yes I certainly do see why 300 ft-lbs would happen in my second case. Recall, I presented that answer in my first post. When I showed the 300 ft-lb figure, it was meant to be the first example of undeniable evidence that the second calculation was completely in error. Now I/we know the actual reason why. Thanks.
 
  • #33
Good good, glad I could be of help.
 
  • #34
J-D-H said:
"Is there anything else we can help you with?" No, not really. BTW, the "we" in that sentence makes sounds like you surely must be the forum moderator. If not, maybe the word should have been "I"?

My post #24 was merely admission that we seemed to be done. There was no criticism intended whatsoever -- but exasperation certainly was evident. I tried to summarize, said thanks to all, and then tried to bring this to an end courteously. If you'll read between the lines, you may understand that post #24 was also prompted by the "boring thread" and "moderator intervention" comment. That, and the realization that though I kept asking for us not to rehash the correct calculation method, we seemed to keep doing so over and over again. From my POV, only xxChrisxx's recent post really got to the heart of the matter, but that came after a lot of wheel spinning.

Enough of this conversing about conversing. Again, thanks to those who genuinely tried to help. I do now (and did) understand torque, but more importantly in this case, the true problem with the known wrong "simplified" calculation is clear. Good!

Well, I apologize for not being able to state why you were incorrect without rehashing the correct calculation method. From our POV we were telling you why you were incorrect in the easiest possible way. Perhaps we can write this down as a simple misunderstanding and hope everyone learned something.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
1K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 14 ·
Replies
14
Views
4K
Replies
14
Views
1K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K