Boring speeds and feeds (RPM, feed rate, theoretical roughness)
Spindle speed, feed rate, cutting time and theoretical roughness for ID boring. Enter the finished hole diameter.
◉Boring calculator
Spindle speed n—rpm
Feed rate Vf—mm/min
Cutting time—
Theoretical roughness Rz—µm
n = 1000 × Vc ÷ (π × D) Vf = f × n Time = L ÷ Vf Rz = f² ÷ (8 × r) × 1000
Red = input dimensions, green = rotation and motion. Schematic, not to scale.
Notes
- Boring bars with long overhang chatter easily, so conditions are often set lower than for OD turning.
All values are guides. Start from the tool maker’s recommended cutting data and adjust for your machine, workholding and coolant. Calculations run in your browser; nothing you enter is sent anywhere.