Speeds and Feeds Calculator
Get spindle RPM and feed rate for drilling, milling or turning, starting from typical cutting speeds for your material.
- Feed rate
- Surface speed used
- Cut time
- Metric
- CNC Setting
Setup Sheet
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| Operation | Tool | RPM | In./Min. | Remove |
|---|
How to Calculate Speeds and Feeds
Cutting speed is how fast the cutting edge moves across the material, in surface feet per minute (SFM). Each material has a comfortable range. Spindle RPM comes from that speed and the diameter that's turning: the tool for drills and end mills, the workpiece on a lathe.
Worked Example
Starting Cutting Speeds for HSS Tools
| Material | HSS (SFM) | Carbide (×2.5) |
|---|
From the University of Florida MAE Design and Manufacturing Lab speeds and feeds guide, which says to multiply HSS speeds by 2.5 for carbide. Drill feeds there: 0.002–0.004 in/rev for ⅛″–¼″ drills, 0.004–0.008 for ¼″–½″. Milling chip loads: aluminum 0.004–0.012, steel 0.003–0.004, hard stainless 0.002–0.004 in/tooth.
Tips
These are starting points. Coated tools, rigid setups and flood coolant allow more; hand-fed drill presses with a squirt of oil often need about 60% of the table speed and feed. If the chips turn blue or the tool squeals, slow down; if you get dust instead of chips, feed harder. The tool maker's chart for your exact tool beats any general table.