Burrs

Likely causes

• An edge too dull or too rounded for the feed
• Notch wear or chipping at the depth of cut
• Cutting straight off an edge

What to change

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

1. 1

   Use a sharper insert: positive, PVD-coated or ground

   Most of all at feeds under .004 IPR (0.1 mm/rev).

   Sandvik · Mitsubishi

2. 2

   Raise the feed if it is too light for the edge’s rounding

   Sandvik · Mitsubishi

3. 3

   Fix notch wear: a harder grade, or vary the depth of cut

   Sandvik · Mitsubishi

4. 4

   Chamfer or radius in and out of the cut

   Sandvik

5. 5

   Turn the coolant on

   Mitsubishi

Work it out

• Surface finish predictor — the feed an Ra callout allows
• Turning speeds & feeds — a starting speed, feed and depth for your insert

Often comes with

• Notch wear at the depth-of-cut line
• Built-up edge