Any time you're working with cutting edge material you need at least carbide cutters, with constant coolant flow, the annular cutters *MUST* have flow through the center to cool the inner tiny cutting points and flow the chips outward for clearing. I use TRIM E206 mixed ten to one with water and let it flow when cutting T1 or Weldox. One dry spot or any time the cutter chatters or sticks for a second, probably time to send it for sharpening. Life with good steel.