The time taken to drill a hole though a $$25$$ $$mm$$ thick plate with the drill rotating at $$300$$ $$rpm$$ and moving at a feed rate of $$0.25$$ $$mm$$/revolution is

The abrasive material used in grinding wheel selected for grinding of ferrous alloys is

Determine the transformation ratio $$(TR)$$ of the gear train connecting the spindle and the lead screw of $$4TPI$$ required to cut $$1.0mm$$ pitch screw threads in a center lathe