On Friday, July 21, 2017 at 11:06:51 PM UTC-4, Martin Eastburn wrote:
G10 was outlawed 25-30 years ago. FR4 was the replacement. G10 catches
on fire. FR4 self extinguishes. If you look you can't tell. If you
read or design with them - really design transmission lines you know.

Martin

On 7/21/2017 8:13 PM, rangerssuck wrote:
On Wednesday, July 19, 2017 at 10:18:58 PM UTC-4, Ignoramus17939 wrote:
I am parting out a PCB drilling CNC machine. Inside of it, there is a
good pile of a few lbs of carbide "PCB Drills". These are tiny drills
and perhaps end mills, with what looks like 1/8" shanks.

I wonder if there is any non-PCB use for them. I do realize that these
carbide drills can only be used in CNC equipment, and I have a CNC
milling machine. Trying to think of any good use cases but can't.

i

They are carbide. They cut through hard stuff. They are used in PCB manufacturing because G10 fiberglass is really rough on HSS bits.

EVERYTHING you have heard about their brittleness is true. I have broken 0.4mm drills simply by picking them up wrong.


Fine. FR4 is deadly abrasive for HSS drills as well. OK?