Cutter / Torx Specs

Many woodturners like to make their own tools.  For reference, this chart includes cutter sizes, specific screws, torx wrenches, and thread specifications for the screw thread.

It is recommended that the specific torx screws are used with the cutters.  The cutter inside diameter has a taper which matches the taper on the screw.  This helps with secure lock up of the cutter.

Cutter NumberCutter Diameter MetricApproximate Cutter Diameter InchApproximate Cutter Diameter FractionHunter Screw NumberScrew Threads or Tap SizeTorx Wrench
#1 6mm  0.236 15/64 #1 M2.5-0.45 T-9
#2 8mm  0.315 5/16 #2 M3-.5 T-9
#3/#5 10mm  0.394 3/8 #3/#4/#5 M4-.7 T-15
#4 12mm  0.472 1/2 #3/#4/#5 M4-.7 T-15