Compression Bit Advice

[Ger21]

I've never used such a small diameter compression bit.
I'd probably make 2-3 passes, and a full depth finish pass, which should improve your cut quality.
In most cases, if the bit is making a lot of noise (screaming?), it's because you're feeding it too slowly.

[dcrowder]

Cheers for the advice Gerry, the bit was definitely 'screaming'... I was feeding it slowly because of the DOC being 4.2mm for a 4mm sheet and me worrying about snapping my new bit due to its length.

Can you tell me if what I've read about the DOC being half the diameter of the bit is true? I've had success with cheap Chinese carbide up cutting bits, cutting deeper than their diameter and everything seemed to be coping.

[Ger21]

Can you tell me if what I've read about the DOC being half the diameter of the bit is true?

No, not for wood.

For bits 6mm and smaller, I use DOC = Diameter.
Once you get to 10mm, you can easily use a 20mm DOC. The material makes a difference, though. Feedrate as well.

[dcrowder]

No, not for wood.

For bits 6mm and smaller, I use DOC = Diameter.
Once you get to 10mm, you can easily use a 20mm DOC. The material makes a difference, though. Feedrate as well.

This answer is worth 1000 googles!