E46 Fanatics Forum banner

Torque wrench with adapter and extension - how does this affect reading?

6K views 9 replies 6 participants last post by  ken@bimmertools 
#1 ·
I have a 1/2" drive torque wrench with a 5" long 1/2" drive extension then a 1/2" drive to 3/8" drive adapter then a deep socket 3/8" drive 16mm socket (doing a steering wheel swap).

If I need 46 ft. lbs. of torque on the bolt, does all this extra length mean I need to change the setting on the wrench?

Need help ASAP.

Thanks in advance!

-John
 
#4 ·
"...Ratchet extensions do not affect the torque reading, because they do not extend the lever arm. However, they do increase the tendency to "slant" the wrench from the right angle needed for an accurate measurement. Always ensure your torque wrench is parallel to the plane the fastener sits in. *"Crow's feet" and other extensions added between the wrench head and fastener cause the wrench to understate torque, because they add leverage on the end where you are measuring torque. *It does not matter, from a torque measurement standpoint, where you grip the wrench. However, for safe use, grasp it by the handle grip. *Never use a torque wrench that's been stored with the spring set above 10% of capacity. *Always "exercise" a torque wrench through its full range of settings before using it. *Always apply smooth, steady pressure to a torque wrench-do not jerk it. *When a torque wrench breaks away, stop turning with it. Continuing to turn can damage the wrench and cause personal injury. *Do not use a torque wrench for more than an hour without setting it to zero. *Always store a torque wrench with the spring set at zero. *Use a torque wrench as sparingly as possible; that is, don't use it instead of a regular wrench when you don't need to check torque. *Always follow the instructions that come with the torque wrench. *Know the location of a qualified service center to calibrate and lubricate your wrench...."

from

http://ecmweb.com/mag/electric_torque_wrenches_critical/
 
#5 ·
Actually, while extensions do not affect the torque by changing the "distance", they do affect the reading due to torsion. How much? I have no idea. I would imagine not much, but I try to avoid them as much as possible, or if I have to, use the shortest extension required or use a thicker one. In your case, I wouldn't worry about it, but keep it in mind for cases where you use a long extension.
 
#6 ·
Yes, torsion does affect the readings; but at 46 ft-lbs, I don't think it will be very much. Well unless you have some low-grade cheap extensions. I remember trying to remove a stubborn bolt with a cheap-o extension I bought in a hurry. Man, after I was done, that thing looked like a twisler. :D Just concentrate on keeping that wrench parallel to the bolt you are torquing, and you should be fine.
 
#7 ·
Thanks to everybody!

Regarding the post that said to not use a torque wrench stored above 10% setting and to reset to 0% when storing, I think it was Wikipedia that said to store at 20%. How in the world is a DIYer to know what to do?

I'm storing mine at 0% and hoping for the best!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top