METRIK MFG
CNC Feeds & Speeds Reference
A practical formula reference for CNC milling cutting speed, spindle RPM, feed per tooth, feed rate and material removal rate.
This page is the reference layer for Metrik MFG’s milling calculators. It shows the core relationships and their units so a user can inspect the calculation chain.
Formula table
| Item | Formula | Units |
|---|---|---|
| Cutting speed | Vc = πDn / 1000 | m/min |
| Spindle speed | n = 1000Vc / (πD) | rpm |
| Feed rate | vf = fz n z | mm/min |
| Feed/rev | fn = vf / n | mm/rev |
| Milling MRR | Q = ae ap vf | mm³/min |
Parameter relationship
Vc ↔ RPM ↔ tool diameter RPM × teeth × chip load ↔ feed feed × radial engagement × axial depth ↔ MRR
Practical rules
Use toolmaker cutting data for the starting Vc and chip load. Verify maximum RPM, spindle power, torque curve, feed capability and actual engagement. Never substitute a generic chart for manufacturer data when a specific tool is in use.
Open Speeds & Feeds Calculator →
Sources: DATRON tooling formula reference · Sandvik Coromant.
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