To prevent bending of long shafts due to cutting force

To avoid load on the lathe centres while turning long shafts

To reduce the load on the cutting tool while turning

To ensure to turn at higher cutting speeds than recommend

equal in numbers but unequal in pitch

unequal in numbers but equal in pitch

unequal in numbers and unequal in pitch

equal in numbers and equal in pitch

75 Degree

90 Degree

100 Degree

120 Degree

1 in 10

1 in 15

1 in 20

1 in 25

convex shaped

concave shaped

slightly tapered with smaller end towards work face

slightly tapered with smaller end towards turret face