Turning Troubleshooting

• POOR SURFACE FINISH
• WORKPIECE CHATTER / VIBRATION
• UNACCEPTABLE CHIP CONTROL
• POOR INSERT LIFE:

	Flank wear	Crater wear	Built-up edge
Chipping	Depth-of-cut notching	Thermal cracking	Fracture

PROBLEM	CAUSES	SOLUTIONS
POOR SURFACE FINISH	Feed rate too great for nose radius	Reduce feed rate
		Use larger nose radius insert
	Low cutting speed	Increase cutting speed
	Poor shearing action	Select more positive chipbreaker
		Flood cutting zone with coolant

PROBLEM	CAUSES	SOLUTIONS
WORKPIECE CHATTER / VIBRATION	Poor Set-Up	Use sharp inserts
	Improper insert selection	Select more positive chipbreakers
		Increase feed rate
		Increase lead angle
		Use smaller nose radius tools

PROBLEM	CAUSES	SOLUTIONS
UNACCEPTABLE CHIP CONTROL	Chip too thin	Increase feed rate
		Use more positive chipbreaker
		Select smaller nose radius insert
		Decrease lead angle

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Flank Wear	Excessive heat	Reduce cutting speed.
		Flood cutting zone with coolant
		Select more positive rake chipbreaker
	Work material microstructure contains carbides	Use harder carbide grade

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Crater Wear	Excessive heat at chip/tool interface	Reduce cutting speed
		Flood cutting zone with coolant
		Select more positive rake chipbreaker

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Built-up Edge	Poor shearing action	Use sharp edge inserts
		Use grades with high lubricity surfaces (PVD coated grades, cermet grades, polished carbide grades)
		Use coolant to reduce chip adherence when cutting gummy materials
	High cutting forces	Use more positive chipbreaker
	Low cutting speed	Increase speed

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Chipping	Chatter, vibration	Use sharp inserts
		Select more positive chipbreakers
		Increase feed rate
		Increase lead angle
		Use smaller nose radius tools
	Built-up edge	Increase speed, use PVD coated grade, use coolant
		Decrease feed per tooth
	Excessive cutting force	Use hone or T-land
		Use tougher grade
		Select stronger chipbreaker

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Depth of Cut Notching	Scale part	Increase lead angle
		Increase cutting speed
	High work hardening materials	Select tougher grade
		Select stronger chipbreaker
		Vary depth of cut if possible

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Thermal Cracks	Extreme variation in cutting temperature	Reduce feed rate
		Increase cutting speed
	Interrupted cut	Use stronger chipbreaker

PROBLEM	CAUSES	SOLUTIONS
POOR INSERT LIFE - Fracture	Extreme cutting conditions, excessive cutting force, chatter	Reduce feed rate
		Select tougher grade
		Select stronger chipbreaker
		Make sure set-up is as rigid as possible