48) Crater wear occurs mainly due to

49) A milling cutter of 80mm diameter has nine teeth. It is used to mill a 240mm long work piece. The run over is 4mm and the depth of cut is 5mm. A cutting speed of 12 meters/min. and feed per tooth of 0.15mm has been selected. Determine the milling time.

50) Formula to calculate the value of setover using tailstock setover method to turn taper from diameter D to diameter d to a certain length l of a job (Total length of the job is L) is

51) The value of side rake of the turning tool of geometry of 7-8-5-6-9-4-1 mm will be

52) Find the time requried for a slotting machine for making a complete cut on a plate 600x600 mm if the cutting speed is 8 meters/min, for the return time to cutting time ration 2:3 and feed 2mm/double stroke. Clearance at each end is 75 mm.