Shop Speeds and Feeds
Spindle RPM and feed rate from SFM and chipload by tool / material.
Example
You enter
- Tool drill
- Material steel
- Diameter (in) 0.5
- Flutes (blank: 2 for a drill or end mill, 1 for a lathe tool) 2
You get
- SFM 80
- Chipload ipt 0.005
- RPM 611
- IPM 6.11
Checked against published worked examples from: Machining Data Handbook / project bundled SFM + chipload tables.
Details, formula, and sources
Formula or tableRPM = (SFM × 3.82) / D_in. Feed rate IPM = RPM × chipload × flutes. SFM and chipload from engineering-practice tables keyed to material and tool-type.
Source and editionMachinery's Handbook engineering-consensus values; tooling-manufacturer (Sandvik, Kennametal, Niagara) recommendations by name.
Free accessOlder Machinery's Handbook editions free at archive.org. Manufacturer guides free at each tooling-manufacturer site.
What governsEstimate. AHJ and licensed professional govern.
API field namestool, material, diameter_in, flutes, sfm, chipload_ipt, rpm, ipm
- SFM / chipload table data/construction/sfm-table.json keyed to material / tool-typeMachinery's Handbook + manufacturer typical