Pick your material, tool, and cutter size and this optimizer returns a complete starting point — spindle RPM, feed rate, cutting speed, and chip load — in one step. It pulls recommended surface speeds and chip loads from standard machining data so you do not have to chain three calculators together.
Conservative starting points for milling. Tune by chip color, sound, and finish, and defer to your tooling maker.
How it works
The optimizer looks up a cutting speed (SFM) for your material and tool, converts it to RPM for your diameter, then sets feed from a recommended chip load scaled to the cutter size:
RPM = (SFM × 3.82) / diameter, and feed (IPM) = RPM × chip load × flutes.
Tips
Start near these values and increase once the cut proves stable. Drop the feed for slotting or deep cuts, and for light radial passes you can raise it to offset chip thinning.
FAQ
Carbide or HSS? Carbide runs several times faster and is the default for production; HSS suits one-offs and interrupted cuts.
Why does RPM change with diameter? Surface speed is fixed by the material, so a smaller cutter must spin faster to reach the same SFM.
For full tables see the Feeds and Speeds Chart, and the individual RPM, Feed Rate, and Chip Load formulas.