Speeds and feeds calculator
Spindle speed, feed rate and metal removal rate for an end mill, a drill or a lathe cut, from published starting surface speeds and chip loads.
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Comes with the machinist plan: every tool for the role, from $10.20 a month at the launch price.
- Your own numbers, worked out as often as you like
- The full setup sheet you can print or save to My work
- 5 cited sources, linked, with the checks to make
- Every other tool for the same role, in the same plan
- A plain-words read of your result (a fuller AI read with the Bifrost AI add-on)
Included in these role plans
Example result · fictional numbers
What you get: setup sheet
Worked out by this tool from its default inputs. Its role plan lets you run your own numbers, print the sheet and save it.
3,438 RPM at 27.50 in/min: 1.72 cu in/min, about 1.88 hp at the motor of your 10.0 hp, 0.44 min per 12.00 in pass
- Surface speed
- 450 ft/min (starting value for milling 1018 low-carbon steel with carbide)
- Spindle speed
- 3,438 RPM
- Feed rate
- 27.50 in/min (3,438 RPM × 4 × 0.0020 in per tooth)
- Metal removal rate
- 1.72 cu in/min
- Starting chip load for this size
- 0.0020 in per tooth (diameter over 1/4 to 1/2 in)
Power and time
- Unit power
- 0.70 hp per cu in/min for 1018 low-carbon steel, sharp tool
- Power at the cutter
- 1.20 hp (1.72 cu in/min × 0.70)
- Power at the motor
- 1.88 hp with 25% for tool wear at 80% efficiency
- Machine horsepower
- 10.0 hp: the cut uses 19% of it
- Largest removal rate the motor can take
- 9.14 cu in/min
- Time per pass
- 0.44 min for 12.00 in at 27.50 in/min
Also on the sheet
- Same cut, HSS and carbide · 3 lines, starting with “Carbide”
- Tool life and step-over options · 6 lines, starting with “At 80% surface speed”
- Setup checklist · 6 lines, starting with “Machine maximum RPM and horsepower checked”
The plain-words read of this example
Milling (end mill) 1018 low-carbon steel with carbide at 0.5000 in: 450 ft/min gives 3,438 RPM. At 0.0020 in per edge the feed is 27.50 in/min and the removal rate 1.72 cu in/min. That takes about 1.88 hp at the motor of your 10.0 hp. At 80% speed the tool might last about 2.4 × as long.
5 cited sources
- Machinery's Handbook, 31st Edition (Industrial Press (Oberg, Jones, Horton and Ryffel, 2020))
- Machining formulas and definitions (Sandvik Coromant)
- General turning formulas and definitions (Sandvik Coromant)
- In the Loupe: machining guides, speeds and feeds, chip thinning (Harvey Tool)
- 29 CFR 1910.212, General requirements for all machines (Occupational Safety and Health Administration)
Plus 6 step-by-step checks, a print layout and a link that reopens it with your numbers.