62) If the recommended cutting speed of mild steel is 20 m/min, what is the rotational speed (rpm) required for a Dia=20 mm drill bit?

63) Tool will rub against the work surfaces and the cutting force increases when

64) The rake angle required for machining cast iron is

65) Helix angle in twist drill determines the

66) Calculate the tailstock offset in mm for the job details given below using tailstock offset method for taper turning. Big diameter (D) = 36 mm, Small diameter (d) = 32 mm, Length taper (I) = 125 mm, Total length of job (L) = 250 mm