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Spiral Bit Router Bits

Genmitsu MC40A — 1.0mm Flat Upcut (Micro)

Genmitsu
Overview
Ultra-fine 1.0mm flat upcut end mill for micro-detail CNC work. Shank: 1/8in (3.175mm). Cutting dia: 1.0mm. Flutes: 2. Max RPM: 30,000. Extremely delicate - requires low DOC and feed rate. Not for beginners.
Properties
Difficulty
expert
Pros
  • Fine detail in tight geometry
  • PCB isolation routing
  • Inside corners smaller than 3.175mm
  • Included in MC40A set (spend these before buying dedicated micro bits)
Cons
  • Snaps instantly with wrong settings
  • Max 0.1mm DOC — any more and it breaks
  • Slow — max 200–250mm/min
  • No plunge cuts — always ramp in
  • Not for production use
Best For
  • PCB engraving (FR4 board)
  • fine text engraving in hardwood
  • intricate inlay patterns
  • micro-detail relief carving
  • jewelry in soft metals
Avoid For
  • Softwoods with loose grain (fibers catch micro bit)
  • depths over 0.5mm without multiple passes
  • aggressive plunging
  • machines with high runout
Storage
Dry storage. Keep protected — even setting them down wrong breaks the tip.
Brands
Genmitsu (SainSmart)