Feeds/Speeds advice for brass

Project is a clock dial in brass, 0.03" thick. Tool was a 30 degree carbide 1-flute insert in a 12mm shaft (Amana). It had a tip width of 0.005, chosen to maximize detail very small letters. Cuts looked great until the tip broke.

Cut depth 0.008" per pass, max depth 0.015"
RPM 6000, Feed 100 IPM (Amana’s guidance), plunge 50 IPM
V-carve profile cuts with flat bottom. No clearance tool (none would fit in the narrow spaces I’m cutting)
I left the plastic protection on which could have dragged on the bit, and maybe affected the depth measurement?

I still have inserts:

  • 30 deg tip diameters of 0.01 and 0.02
  • 60 deg tip diam. 0.005 and 0.01
  • 90 deg, tip diam. 0.005 and 0.01

What should I change?

  • Take off the plastic
  • Different cutter?
  • Different feed/speed?