[ssashton]

I ordered some single flute 1/8" down cutting end mills. I've ordered such things before and they usually have a single flute that is the cutting edge, say 17mm long.

These ones are different. They have a main flute that goes most of the 17mm, but it is not the primary cutting edge and does not go 100% to the end. There is a secondary shorter flute at the cutting end.

Is this some re-grind method or is it specific for plastics or something? Anybody seen this before?



It's easier to see in a video: https://photos.app.goo.gl/hKjsNkYcNdhxJQL3A

[Superman]

It is designed to minimise damage on top and bottom faces, and leave nice edges without burrs.

Typically, works well on most materials.

[ssashton]

It is designed to minimise damage on top and bottom faces, and leave nice edges without burrs.

Typically, works well on most materials.

Wait you're right, that primary cutting flute is an up cut, which makes this a compression cutter. Damn it, I ordered down cutters.