CNC router bits and carbide cutting tools with tutorials and technical guides

2-flute Extended-reach Ball-nose Carbide End-mills (MM204) - 1/4 in. (0.250 in.) shank

Think & Tinker 2-flute ball-nose end-mills feature an "gashed past-center" plunging tip style enhanced with revisions to the cutting edges and flute profile. These changes result in bits with improved cutting properties in a wider range of materials. Our tools are routinely used to shape and engrave metals, plastics, all types of woods and a wide variety of composites.

Manufactured in the USA, every tool is:

  • 100% measured / optically inspected to insure that EVERY tool meets, or exceeds, our published specifications
  • available with depth rings precisely positioned to ±0.0015 in. (0.038mm), virtually eliminating the need for resetting Z-axis zero between tool changes (with bits of same overall length)
  • made from premium grade submicrograin tungsten carbide (HRa 92, HRc 80)

Extended reach is accomplished via the addition of a reduced diameter neck at the end of the flutes which allows very deep multi-pass contouring and pocketing. This capability is essential for cutting through thick materials from a single side. The inital application that drove the creation of these tools was the need to easily contour and shape the bodies and necks of solid-body electric guitars.

  • Geometry - 2 flute up-cut, 1/4 in. (6.35 mm) shank, ball-nose tip
  • Length - as indicated ±0.010 in.
  • Cut Diameter - nominal +0.0000 -0.0010 in.
  • Neck Diameter - 90% of cut diameter ±0.005 in.
  • Runout (TIR) - max 0.0002 in.
  • Max. depth of cut - nominal ±0.020 in.
  • Anticipated Life - depends on material being cut (min 10,000 in, western red cedar)
  • Material - solid submicrograin carbide
  • Operating RPM - CNC certified operation 1k RPM to 40k RPM
  • Ball-nose tip provides smooth cutting at step overs up to 8%
  • High flute volume supports high feed rates / chip loads
  • High aspect ratio flutes for deep single-pass cutting
  • Reduced diameter neck for very deep multi-pass cutting

Carbide 2-flute extended-reach ball-nose  end mill for deep relief sign carving

Tip Diameter MaxDiameter LOC Reach Flutes Draft Angle Coating Shank OAL Depth Rings Reviews Part Number Price
0.2498" (6.34mm) 0.2500" (6.35mm) 1.500" (35.56mm) 1.85" 2 0.001° 1/4" 3.00" (76.2mm) Available MM204-2500-185BN


0.2498" (6.34mm) 0.2500" (6.35mm) 1.500" (35.56mm) 1.85" 2 0.001° ZrN 1/4" 3.00" (76.2mm) Available MM204-2500-185BNC