Cutting time calculator
Estimate the spindle speed, feed rate and total machining time of a turning or drilling pass.
How it is calculated
Spindle speed n = 1000 × vc ÷ (π × D). Feed rate vf = f × n. Machining time t = passes × L ÷ vf.
Worked example
L = 200 mm, vc = 150 m/min, D = 50 mm, f = 0.2 mm/rev: n = 955 rpm, vf = 191 mm/min, t = 1.05 min.
Steps
- Enter the cut length and the number of passes.
- Enter the cutting speed from the tool supplier and the diameter being cut.
- Enter the feed per revolution, then read the rpm, feed rate and time.
Frequently asked questions
Does this include approach and overrun?
No. Add the approach and overrun distances to the cut length before you enter it.
Where do I get cutting speed?
From the tool manufacturer catalog for your material and insert grade. Use the CNC speed and feed calculator for a detailed check.
Is this accurate for milling?
Use the feed per tooth and the number of teeth for milling. The feed per revolution here is for turning and drilling.
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References
Cutting speed and feed relations from ISO 3685 (tool life testing with single-point turning tools) and standard machining data handbooks.
Estimates for information only. Verify critical values with a qualified engineer or your supplier standards.