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Baseline SFM ranges for common turning materials.
Formula
RPM = (SFM × 12) / (π × D_workpiece)Units: inch
Machine-readable reference
Structured metadata for formulas, tags, canonical status, and future diagram support.
Slug
turning-sfm
Category
Feeds & Speeds
Canonical
Yes
Updated
4/23/2026
Units
inch
Tags
turning, sfm, lathe
Source
Machinery's Handbook, 31st ed., Turning
Use the workpiece diameter rather than tool diameter when converting turning SFM to RPM.
RPM = (SFM × 12) / (π × D_workpiece)
Source: Machinery's Handbook, 31st ed., Turning