Myth that socket extensions change torque wrench readings

The issue is dynamic vs. static.

Point A on the force vs. displacement curve is the only static point. Both ends of the spring (or in our case the extension) apply equal force (torque wrench force equals force applied to fastener).

All other points on the curve are dynamic. At equal torsion angles (x-axis), the energy required to load the spring (y-axis) is greater than the energy required to release the spring. The greater the hysteresis the greater the energy loss.