Your friendly feeds & speeds buddy for new CNC mill users to grow with. Conservative-by-default starting numbers — always verify by sound, chip shape/color, overall feeling of cut. See bottom of page for more info. These are starting points, not guarantees.

Units

Workpiece

Other materials are coming — tables need verification before they go live. Today everything assumes 6061 aluminum.

Tool

Common: 0.0625, 0.125, 0.25, 0.375, 0.5, 0.75
Pocket / Adaptive: 2–3 flutes preferred for chip evac; 4 OK for shallow. Facing & Contour: 4–8 flutes give better finish.
Caps the maximum axial DOC the tool can reach.

Setup

Heavier machines damp chatter and resist deflection — they tolerate more feed and DOC. Light machines need a derate.
EST.= Only Heavy Machine Class is personally verified. Start Conservative on a new Machine Class.
Not sure? Pick 2 or 3 to scale things back.
Be sure to tram the vise and shortest tool stickout without crashing the spindle. Double/Triple check!
Hard ceiling — recommendations never exceed this.
Auto-suggested. Tools ≥ 1/8" cap at 6000; under 1/16" or engraving allow up to machine max.

Operation

Pocket / Adaptive: heavy chip removal. Facing: skim the top flat. Contour: finish the wall around a part. Drilling: peck cycle (G73 chip-break + G83 full-retract).
Roughing: stock removal — full numbers. Finishing: separate operation for surface quality — chip load × 0.5, RPM × 1.1 (capped at op cap), light stepover and stepdown.
Conservative: lower SFM, modest DOC, lots of margin. Best for new setups, unfamiliar tools, listening to your machine.
Pro: top of the recommended range. Numbers stay below 1× tool diameter — still verify on a test cut, listen for chatter, watch chip color.

Recommended starting point

Spindle
RPM manual
Cutting Feed Rate
IPM manual
Feed per Tooth
(Chip Load)
in manual
Surface Speed
(SFM)
—ft/min
Axial Depth of Cut
(stepdown)
in manual
Radial Depth of Cut
(optimal load)
in manual
Plunge Feed Rate
—IPM
Listen to the spindle. Smooth hum, no chatter or squeal = good. If the setup feels off, recompute conservatively.
For Aluminum: bright silver chips curling away = good; chips welding to the flutes or packing in a pocket = stop, more lube/coolant or back the feed off.
For Steel: blue chips curling away = good; brown/black chips = stop, you're burning the tool.