The three main processing parameters during turning are cutting speed, feed and depth of cut. Each parameter has an impact on tool life. To achieve optimal turning tool life:

Reduce cutting speed vc (to reduce heat)

Optimize feed fn (to achieve the shortest cutting time)

Optimize depth of cut ap (to reduce the number of cutting passes)

Cutting speed, vc

too low

built-up edge

Cutting edge becomes dull

Uneconomical

Poor surface quality

too high

The flank surface wears too quickly

Poor surface quality

Crescents wear out quickly

plastic deformation

Feed rate fn

too low

long and narrow chips

The flank surface wears too quickly

built-up edge

Uneconomical

too high

Less chip control

Poor surface quality

Crater wear/plastic deformation

High power consumption

chip sintering

chip impact

depth of cut ap

too small

Less chip control

vibration

overheat

Uneconomical

too deep

High power consumption

Broken blade

Greater cutting force

Tool maintenance

Establishing a tool maintenance routine in the shop will extend turning tool life, avoid problems and save costs.

Check insert seat

It is important to ensure that the insert seat has not been damaged during machining or handling.

Check:

Is the tool holder oversized due to wear? Whether the blade can be positioned correctly on the side of the tool holder. Check the gap with a 0.02 mm (0.0008 inch) gauge

No gap is allowed at the fillet between the tool shim and the bottom of the tool holder

Is the blade pad damaged? Pad fillets in the cutting area should not crack

Pad wear due to chip breaking and/or blade impression

Clean blade holder

Make sure there is no dust or chips from machining on the insert holder. Clean the blade holder with compressed air if necessary. If a boring bar with a cutting head is used, 

the interface between the cutting head and the boring bar must also be checked and cleaned when the cutting head is replaced.

Torque wrench

For optimal performance of a screw-clamped tool holder, the insert should be tightened correctly using a torque wrench. Use the recommended torque for each toolholder.

Torque that is too high will negatively affect tool performance and cause blades and screws to break.

Torque that is too low will cause the insert to move, vibrate and reduce cut quality

clamping screw

Be sure to use a torque wrench to ensure the screws are tightened correctly. Apply enough screw lubricant to prevent the screws from seizing. Lubricant should be applied to 

the threads and the surface of the screw head. Replace worn or damaged screws.