Which statement best defines shaft end runout?

Which statement best defines shaft end runout?

• A. Distance the shaft end travels along its axis
• B. Lateral deviation of the shaft end from the true axis
• C. Maximum rotation speed of the shaft
• D. Heat generation at the shaft end

Answer: (B)

The concept tested is how shaft end runout describes the sideways deviation of the shaft end from its intended rotation axis as the shaft spins. When a shaft is perfectly concentric and properly aligned, its end stays right on the rotation axis with no wobble. In real machines, manufacturing tolerances, mounting misalignment, or bearing play cause the end to shift laterally, creating a wobble that shows up as runout. This is measured as the maximum radial displacement of the shaft end from the true axis during a full rotation, typically with a dial indicator as you rotate the shaft. Describing the end’s lateral deviation from the true axis captures the essence of runout. The other ideas refer to movement along the shaft’s length, speed, or heat—none of which describe this radial wobble.

The concept tested is how shaft end runout describes the sideways deviation of the shaft end from its intended rotation axis as the shaft spins. When a shaft is perfectly concentric and properly aligned, its end stays right on the rotation axis with no wobble. In real machines, manufacturing tolerances, mounting misalignment, or bearing play cause the end to shift laterally, creating a wobble that shows up as runout. This is measured as the maximum radial displacement of the shaft end from the true axis during a full rotation, typically with a dial indicator as you rotate the shaft. Describing the end’s lateral deviation from the true axis captures the essence of runout. The other ideas refer to movement along the shaft’s length, speed, or heat—none of which describe this radial wobble.