8mm 上切螺旋刀 – 1/2″ 柄 (AstraHP 塗層)

Finally a bit that matches my metric CAM setup exactly—no more chamfering off-center. Cut a dozen test squares in 19mm birch ply and the finish is glass-smooth, no chip-out. The Astra coating seems to be holding up well after a few hours of hard use.

I was skeptical about metric-ground bits for imperial machines, but this 8mm up-cut spiral ran perfectly in my CNC with zero deflection on solid maple. The chip evacuation is noticeably better than my old standard bits, and the AstraHP coating seems to reduce heat buildup during long runs.

Finally, a bit that actually cuts true to 8mm without any imperial rounding—my joinery fits perfectly now. The AstraHP coating handles hardwood panels like butter, and the up-cut clears chips fast. Worth every penny for metric CNC work.