What tool is used to check the twist of a connecting rod?

To check the twist of a connecting rod, a thickness gauge is the appropriate tool. This instrument allows the user to measure dimensions and detect variations in thickness across the rod, which is crucial for determining if the rod has excessive twist or distortion. By using the thickness gauge, one can assess whether the connecting rod conforms to specified tolerances, ensuring proper alignment and function in an engine.

Calipers, micrometers, and torque wrenches serve different purposes. Calipers and micrometers are used for measuring linear dimensions but do not specifically assess twist or distortion. A torque wrench is designed for applying specific torque to a fastener, rather than measuring physical deformities like twist in components. Hence, the thickness gauge is uniquely suited for the task of evaluating the twist in a connecting rod.