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Surface finish (Ra)

Theoretical Ra from feed and nose radius, mapped to ISO N classes — or work backwards from a target Ra to the maximum feed you can run.

Cut

Target optional — computes the max feed for it

Formulas used

Ra = f² · 1000 / (32 · rε)Theoretical roughness from feed and nose radius (µm).
fmax = √(32 · rε · Ra / 1000)Maximum feed that can still reach the target Ra.