If it is placed at 90 degrees to the torque wrench there will not be any effect on the applied torque. I googled it and came up with this formula
E- Effective length of extension - measured along the centerline of the torque wrench. L Lever length of the wrench - center of grip to center of drive. T(W) - Torque set on the wrench. T(E)- Torque applied by the extension to the fastener.
T(W) = T(E)* L/L+E
T(E) = T(W)* (L+E)/L
Supposedly instructions from a Husky torque wrench
This is accurate. In the torque manual that is used by Navy Aviation, they provide this same formula. If the crow's foot or torque adapter (dogbone) is extended past the head, the actual applied torque is higher than the reading on the wrench. If it is set below the head of the torque wrench, the applied torque is less.
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