A cylinder of 25 mm diameter and 100 mm length is turned with a tool, for which the relation VT0.25 = 55 is applicable. The cutting velocity is 22 m/min. For a tool feed of 0.046 mm/rev, the number of tool regrinds required to produce 425 cylinders is
=280rpm
Time/piece=Lt×N=1000.046×280
=7.76min
Total time =425×7.76=3299.7min
T=(50V)Vθ.25=(5522)4=39
No. of tool regrinds=3299.739=85