Rough, torn or hairy finish

Likely causes

• Feed too high for the nose radius
• Material welding to the edge (built-up edge) and tearing the surface
• Chips breaking against the finished surface
• Vibration
• Notch wear at the depth-of-cut line

What to change

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

1. 1

   Use a wiper insert or a larger nose radius

   Either one lets the same feed leave a finer finish.

   Sandvik · Mitsubishi

2. 2

   Raise the cutting speed

   When the surface is torn or smeared: a hotter cut stops material welding to the edge.

   Sandvik · Mitsubishi

3. 3

   Use a sharper, more positive insert

   Sandvik · Mitsubishi

4. 4

   Change the chipbreaker or entering angle to steer chips away from the part

   Sandvik · Mitsubishi

5. 5

   Fix any chatter first

   Sandvik · Mitsubishi

6. 6

   Lower the feed

   The surface finish predictor gives the feed for an Ra callout.

   Sandvik

7. 7

   Turn the coolant on

   Mitsubishi

8. 8

   For notch wear, a cermet grade or a lower speed

   Sandvik

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

• Built-up edge
• Chatter and vibration