Manufacturing Reference

Machining Parameters

A practical reference for cutting speed, spindle speed, feed rate and depth of cut for common machining operations.

Turning Parameters

In turning, the cutting tool moves relative to a rotating workpiece. The main parameters are cutting speed Vc, spindle speed n, feed f and depth of cut ap.

Core Parameters

Vc — Cutting Speed

Surface speed between cutting tool and workpiece.

m/min

n — Spindle Speed

Rotational speed of the spindle.

rpm

f — Feed

Distance travelled by the tool per revolution.

mm/rev

ap — Depth of Cut

Radial engagement of the cutting tool.

Turning

Basic relationships used to determine spindle speed and feed during turning.

Spindle Speed

n = (Vc × 1000) / (π × D)

Symbol	Meaning	Unit
n	Spindle speed	rpm
Vc	Cutting speed	m/min
D	Diameter	mm

Typical Cutting Speed Ranges (Vc)

Approximate starting ranges. Always verify against the specific tool manufacturer's recommendations.

Workpiece Material	Carbide Tool (m/min)	HSS Tool (m/min)
Carbon / Alloy Steel	80 – 220	15 – 40
Stainless Steel	60 – 160	10 – 30
Aluminum	200 – 600	50 – 150
Cast Iron	80 – 180	20 – 50
Brass	120 – 300	40 – 100

Milling

Milling uses a rotating multi-edge cutter. Feed rate depends on feed per tooth and the number of cutting edges.

Milling Feed Rate

Vf = fz × z × n

Vf — Feed Ratemm/min

fz — Feed per toothmm/tooth

z — Number of teeth—

n — Spindle speedrpm

Feed Rate Ranges

Feed selection has a strong influence on productivity, cutting forces and surface finish.

Operation	Condition	Typical Feed
Turning	Roughing	0.15 – 0.40 mm/rev
Turning	Finishing	0.05 – 0.15 mm/rev
Milling	Roughing	0.03 – 0.12 mm/tooth
Milling	Finishing	0.01 – 0.05 mm/tooth

Feed values shown here are starting-point ranges rather than universal cutting conditions. Tool geometry, machine rigidity, coolant, workholding and material hardness can significantly change the optimum value.

Depth of Cut

Depth of cut controls how much material is removed in each pass and directly affects cutting force and power demand.

Roughing

Prioritize material removal rate while maintaining acceptable tool load and machine stability.

Semi-Finishing

Reduce engagement and prepare a consistent allowance for the final finishing operation.

Finishing

Smaller engagement is generally used to improve dimensional accuracy and surface finish.

Calculations & Formulas

Fundamental machining equations and sample calculations for estimating parameters.

Formula Summary

Spindle Speed

n = (Vc × 1000) / πD

Turning Feed Rate

Vf = f × n

Milling Feed Rate

Vf = fz × z × n

Example: Milling Spindle Speed & Feed Rate

1. Given Parameters

Cutter Diameter (D): 50 mm
Cutting Speed (Vc): 120 m/min
Number of Teeth (z): 4
Feed per Tooth (fz): 0.12 mm

2. Calculation

Step 1: Find RPM (n)

n = (120 × 1000) / (3.1416 × 50)n ≈ 764 rpm

Step 2: Find Feed Rate (Vf)

Vf = 0.12 × 4 × 764Vf ≈ 367 mm/min

Engineering Note

Calculated values should be treated as initial setup parameters. Final cutting conditions should be validated against the tool manufacturer's data, machine capability, workholding, coolant and actual cutting behavior.

Reference Status

Formula relationships are standard machining relationships. Typical cutting-speed and feed ranges are approximate starting values and should not replace manufacturer recommendations.