Manual
68
4. Boring
Insert shape and entering angle/lead angle
Use entering angle 90° (0°) for roughing and 92°(-2°) for nishing.
Less force in the radial direction gives less radial deection and
vibration. Triangular-shaped inserts (T-style) are rst choice for
boring operations. CoroTurn® 107 inserts meet these requirements
and are rst choice.
Nose radius
The nose radius, RE, on the insert is a key factor in turning
operations. Selection of nose radius depends on the:
• Depth of cut, AP
• Feed, f
n
and inuences the:
• Surface nish
• Chip breaking
• Insert strength
Small nose radius
• Ideal for small cutting depths
• Reduces vibration
• Less insert strength
Large nose radius
• Heavy feed rates
• Large depths of cut
• Stronger edge
• Increased radial forces