Counter-bore tools and parts...

[Hammerhead]

(01-18-2017 )Rig Wrench Wrote:  Does anyone know how to compensate for an extension on a torque wrench? Like if the head gets torqued to 300 ft lbs, but then you put a 10" extension it to get enough depth with the socket, does it change the accuracy? Maybe its been discussed before. Just checkin

Good question!
I would want to keep the extension length as short as possible.
I'm not sure if an impact extension would be harder and lose less torque or if it would be designed to actually absorb some of the torque due to the very nature of high torque impact guns so that they won't shatter? I'd like to hear more of this from someone that would know about it.
A test would be to torque a bolt up to spec with the extension, then remove the extension and retorque the bolt to check. It would require one that you access withou the extension of course, but it should give you an idea of the net loss of the extension.
I know my 10" 3/4 drive extension I use to torque my wheel nuts doesn't noticably twist up to 475 ft/lbs. I've had somebody torque up while I watched to actually see if it did. It's not a fancy brand name one, but it is quite solid.