Torque Wrench settings with extensions

[ixtlan]

Since I did this research might as well post it here too.
(Feel free to move to another forum if desired)

Torque Wrench settings using extended tools such as wrenches.


Here is the math to use:


S= Handle Setting
T= Torque applied to the end of the adapter (Extension)
La = Length of handle in inches (Torque Wrench)
Ea = Length of extension in inches (The wrench length from attach point to wrench surfaces, aka length added)

Example
Desired to exert 100 inch pounds on the end of a torque wrench with a 12 inch handle with a 6 inch extension attached.

S= T x La
------
La + Ea

S= 100 X 12
--------
(12 + 6)

S= 1200
-----
18

S = 66.6 inch pounds (Setting on Torque Wrench)

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[Riptide]

Help me out here. The manual for my torque wrench says:

Regular socket extensions which extend directly under the drive head along the axis of rotation of the ratchet do not affect the calibration of the torque wrench.

That would imply that you can use any extension you want as long as it's a straight one and it won't affect anything.

Am I misunderstanding something?

 

[klaw]

Help me out here. The manual for my torque wrench says:



That would imply that you can use any extension you want as long as it's a straight one and it won't affect anything.

Am I misunderstanding something?

If the extension adds length to the leverage of the torque wrench as in the pictures above you have to make allowances for the added lever length. If you're just using a socket extension but the socket stays inline with the original pivot point of the torque wrench there is no additional leverage and therefore no adjustment is required. Another way to consider it is if the socket extension is 90 degrees to the plane of rotation of the torque wrench, no adjustment is required. Hope that helps.

 

[Riptide]

Gotcha. So just a straight extension is no problem.

A swivel adapter OTOH? Not so.