GlenCalc

Cutting speed calculator

Tooling makers publish a surface speed for each material, in surface feet per minute (SFM). Typical HSS values: mild steel 80–100, aluminum 250+, hardwood 500+.

Your answer

Spindle speed688 RPM
Surface speed27.4 m/min

Worked out in your browser. Nothing you type is sent to a server.

How we worked it out

Updated as you change the numbers.

  1. RPM = SFM × 12 ÷ (π × diameter) ≈ 3.82 × SFM ÷ diameter.

Method and assumptions

Start at the low end of the range for HSS tools and deep holes; carbide tools can run 2 to 3 times faster.

Questions

What RPM for a 1/2 in drill in mild steel?

About 690 RPM at 90 SFM.

Sources

Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.

Embed this calculator on your site

Free to use. Paste this where you want the calculator; it runs in your visitors’ browsers, sets no cookies and sends nothing to us.

Related calculators