2.1x12x3.175 router bit for metal pcb

2.1x12x3.175 router bit for metal pcb
A 2.1mm x 12mm x 3.175mm router bit is a highly specialized CNC milling tool designed primarily for cutting, engraving, and depaneling circuit boards.The dimensions break down as follows:

• 2.1 mm Cutting Edge Diameter (CED): The thickness of the cut or groove it produces.
• 12 mm Cutting Edge Length (CEL / Flute Length): The maximum depth the bit can safely plunge or mill in a vertical pass.
• 3.175 mm Shank Diameter (SD): Equal to a standard 1/8" shank, making it universally compatible with most PCB CNC milling machines, desktop routers, and rotary tools (like Dremels with a 1/8" collet). [1, 2]

Material & Build RecommendationsWhen working with metal-core PCBs (MCPCBs)—which typically utilize an aluminum or copper substrate layer for heat dissipation—standard fiberglass router bits will dull almost instantly. To cut through metal PCBs cleanly, look for the following specifications:

• Solid Tungsten Carbide: Ensure the bit is manufactured from high-grade solid tungsten carbide (tungsten steel). This material retains its hardness at extreme temperatures, ensuring a clean finish without melting the board composite or burring the metal backing. [1, 2, 3]
• Corn Cob / Diamond Cut Geometric Flutes: Standard two-flute wood router bits will chatter and break on metal. A diamond-cut or "corn cob" abrasive tooth geometry acts like a high-speed file. It breaks metal and epoxy into microscopic chips rather than long strands, preventing the tool from binding and snapping. [1]
• AlTiN or Diamond Coating (Optional but Recommended): Look for CVD diamond-film or Titanium-based coatings if you are cutting high volumes of aluminum or copper-backed PCBs. This reduces friction and exponentially extends tool life. [1]

Where to SourceWhile an exact 2.1mm variant can sometimes be more difficult to find than standard 2.0mm or 3.0mm bits, specialty industrial tool manufacturers and large electronic component marketplaces carry them: