Think & Tinker, Ltd.
CNC router bits and carbide cutting tools with tutorials and technical guides

5-flute Steel Rule Die Kerf Cutter (MM5D8) Specifications


  • Depth of cut:
       9 mm CKF bit - 0.380 in.
      11.7 mm bit - 0.460 in.
  • Deflection compensation (typical):
      0.002 - 0.004 in. typ.
  • Diameter (normal kerf):
       2 point - 0.0280 in.  ±0.0002 in. 
       3 point - 0.0420 in.  ±0.0002 in.  
       4 point - 0.0560 in.  ±0.0002 in.  
       6 point - 0.0840 in.  ±0.0002 in. 
  • Runout (TIR) - 0.0002 in.
  • Geometry - 5 flute, Blended Helix®, 1/8in. (3.18 mm) shank, fish tail point
  • Length - 1.5 in. ±0.010 in.
  • Anticipated Life: (click for more information)
       5/16 in. Baltic birch plywood -  7,000 to 12,000 linear inches
       5/16 in. maple plywood -  5,000 to 10,000 linear inches
  • Material - solid submicrograin carbide 
  • Operating RPM - CNC certified operation 20k RPM to 100k RPM


  • Cuts 5/16 in. Baltic birch plywood at 90 - 110 in./min. @ 40,000 RPM
  • 5 flute geometry insures long life, and low deflection at high feed rates
  • Fish tail point eliminates  backside breakout and splintering
  • Variable helix design provides more efficient chip extraction and minimizes top surface fuzz and splintering
  • Cutting edge geometry eliminates tearing and pulling, yielding smooth, precise edges and sidewalls


  • Cutting kerf slots in steel-rule die-boards
  • Clean-up cutter for fine inlay pocket finishing.


At the beginning of May 2014, our proprietary T3 flute geometry was incorporated into the design of all 2-point and 3-point kerf cutters. T3 was specifically developed to focus shearing stresses away from the tip of the cutter, significantly reducing bit breakage in systems with less than optimal TIR and backlash characteristics. As a result, bits with the T3 modifications are less sensitive to unexpected changes in wood density and composition as well as rapid changes in feed rate or cutting direction. As an added benefit, the T3 mods also serve to reduce deflection and extend bit life.

5 flute SRD kerf cutter

2-pt SRD tool