cncquoter
runs in your browser — files never uploaded

Steel 4140 CNC machining: cost & machinability

A chromium-molybdenum alloy steel, stronger and tougher than 1018 and often supplied pre-hardened (commonly sold as "4140 PH"). Harder on tooling than 1018 — expect lower speeds and more tool wear. Common for shafts, gears, and high-stress structural parts.

cncquoter's default assumptions for Steel 4140

These are the preset values this tool starts from — every one is editable in the settings panel once you load a file. They're cncquoter's own defaults, not a market survey.

Density
7.85 g/cm³
Stock price
$3.60 / kg
Roughing removal rate
1.1 in³/min
Finishing rate
0.08 min/in² of surface

Example quote

A plain 40 × 30 × 10mm block in Steel 4140, 3mm stock allowance per side, 2 estimated setups, cncquoter's default shop rate ($95/hr, 25% margin) — computed live by the same cost model at each quantity:

QuantityPrice / partTotal
1$127.53 – $212.55$127.53 – $212.55
10$15.09 – $25.15$150.89 – $251.48
100$3.84 – $6.41$384.45 – $640.74

This is one fixed sample shape for comparison across materials — your actual part's size, geometry, and setups will change every number here.

Quote your part in Steel 4140 →