A square threaded screw is used to lift a load W by applying a force F. Efficiency of square threaded screw is expressed as

A CNC worktable is driven in a linear direction by a lead screw connected directly to a stepper motor. The pitch of the lead screw is 5 mm. The stepper motor completes one full revolution upon receiving 600 pulses. If the worktable speed is 5 m/minute and there is no missed pulse, then the pulse rate being received by the stepper motor is

The type of fit between a mating shaft of diameter $25.0^{\begin{matrix} +0.010 \\\ -0.010 \end{matrix}}$ mm and a hole of diameter $25.0^{\begin{matrix} +0.015 \\\ -0.015 \end{matrix}}$ is ______.

Which of the following methods can improve the fatigue strength of a circular mild steel (MS) shaft?