Edge chipping or breaking

Likely causes

• A grade too hard or brittle for the cut
• Feed or depth of cut too heavy for the edge
• An unstable setup or an interrupted cut
• Heat cracks from on-off coolant in interrupted cuts

What to change

Fixes both makers give come first. Change one thing at a time, and see what it does.

1. 1

   Use a tougher grade

   Sandvik · Mitsubishi

2. 2

   Lower the feed

   Sandvik · Mitsubishi

3. 3

   Use a stronger edge: a honed or chamfered edge, a larger nose radius

   Sandvik · Mitsubishi

4. 4

   Make the setup more rigid

   Sandvik · Mitsubishi

5. 5

   For heat cracks: coolant fully off or flooding, a lower speed, and a grade made for thermal shock (often PVD)

   Sandvik · Mitsubishi

6. 6

   Take a lighter cut

   Mitsubishi

Work it out

• Turning speeds & feeds — a starting speed, feed and depth for your insert

Often comes with

• Chatter and vibration
• Chips too short, hard or hammered