316 is a molybdenum-bearing austenitic stainless with better corrosion resistance than 304 — and slightly worse machinability. It is gummier and work-hardens just as fast, so run a touch slower and never let the tool dwell.
Key properties
| Property | Typical value |
|---|---|
| Density | 0.289 lb/in³ (8.00 g/cm³) |
| Hardness | ~79 HRB |
| Tensile strength | ~84,000 psi (580 MPa) |
| Machinability | Fair (work-hardens) |
| Composition | Fe with Cr, Ni, Mo |
Cutting speeds
| Operation | HSS (SFM) | Carbide (SFM) |
|---|---|---|
| Milling | 35 – 55 | 130 – 280 |
| Turning | 45 – 65 | 180 – 330 |
| Drilling | 25 – 45 | 90 – 180 |
Convert to RPM: RPM = (SFM × 3.82) / cutter diameter. Use the Feeds & Speeds calculators.
Tooling and tips
- Sharp TiAlN or AlTiN carbide, 4–5 flutes, variable helix, very rigid setup.
- Heavy flood coolant; commit to a real chip and never dwell.
- Treat it like 304 but a step slower and gummier.
FAQ
Why is 316 stainless considered gummier to machine than mild steel? 316’s high nickel and chromium content makes it more ductile and prone to work hardening under a dull or slow-moving tool, causing built-up edge and poor finish. Sharp, positive-rake tooling and consistent feed help avoid the rubbing that triggers work hardening.
See Cutting Speeds for Stainless Steel and the full Feeds and Speeds Chart.