Chris Collins

Tools · fabrication

CNC router feeds and speeds

Chip load by material and bit size → feed rate, plunge, stepdown, and stepover for router bits; trim-router speed-dial settings; and V-bit depth and width geometry.

Added · updated 28 October 2026

Works with

How to use it

Feed rate = RPM × flutes × chip load. Chip-load ranges are typical published starting points for solid-carbide router bits (bit makers such as Onsrud, Amana, and Whiteside publish similar tables) at 1/8, 1/4, 3/8, and 1/2 inch, interpolated for other sizes. Start in the middle, then adjust by the chips: dust or burning means the chip load is too low (feed faster or slow the spindle); a struggling machine or deflecting bit means too high.

  • Ball-nose and V-bits cut at a smaller effective diameter when shallow; the tool uses it.

  • If your machine cannot reach the minimum feed, the tool suggests a lower RPM instead — slowing the feed at high RPM is what causes burning.

  • Stepdown guidance is conservative for hobby machines: about 1× diameter in soft materials, 0.5× in hardwoods and plastics, and 0.1–0.25× in aluminium.

  • Router dial: Makita RT0701C and DeWalt DWP611 dial speeds from their manuals, interpolated between numbers.

  • V-bit geometry: width = flat tip + 2 × depth × tan(angle ÷ 2).

Sharing

Share link copies a URL that opens this tool exactly as you have it set up. It carries the bit, machine and material settings. Opening a link replaces your own saved settings for the tool; a Restore my settings button brings them back. To write a link by hand, use unit, dia — for example /tools/router-feeds/?unit=mm&dia=6.

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