Quote Originally Posted by RCaffin View Post
Ooh, cheap and a bit nasty.
They may cut some softer materials. They may smear some others - plastic at high speed when they get hot for instance.
That price suggests the carbide is kinda brittle. Been there before - dead easy to break tips off.
0.1 mm tip - yeah, IF and only IF the tip is ground centred, your collets have minimal TIR, and the moon is in the right phase.
Cutting iron? Dreaming imho. Blunt in 5 mm, if not broken.

PCB cutters - similar comments all around.

Kyocera: good brand, very nice finish. You could also try Precise Bits.

V-tips in general: rather doubtful. I tried, for PCB tracks, but went with Precise Bits milling cutters in the end.

Cheers
Roger
yes precise bits might be the best i found so far but very pricey and you must buy in bulk (50$+)
I am looking for a cheaper alternative if possible as there is no grantee for breaking the tips specially on these traditional cutter (the have very thin cutting tips)

But have you actually tried these pyramid cutters yourself or just imagining?
please find this link because it seems very promising to me

Making Pyramid Engraving bits - Home Model Engine Machinist