304 vs 316 Stainless Steel
Side-by-side comparison · Composition · Properties · Selection guide
The only meaningful chemical difference between 304 and 316 stainless steel is molybdenum: 316 adds 2–3% Mo (plus slightly more nickel), which sharply improves resistance to chlorides — salt spray, seawater, de-icing salt and many process chemicals. Strength, formability and weldability are essentially identical, so the choice is decided by environment and budget, not mechanics.
Full datasheets:304 Stainless Steel·316 Stainless Steel
At a Glance
| 304 | 316 | |
|---|---|---|
| Type | Austenitic | Austenitic (Mo-bearing) |
| UNS | S30400 | S31600 |
| Standard | ASTM A240/A240M | ASTM A240/A240M |
| Density | 7.93 g/cm³ | 7.98 g/cm³ |
Corrosion Resistance and Service Limits
304
- General corrosion resistance comes from the chromium-rich passive film; nickel, molybdenum, nitrogen and copper change performance by grade.
- Check chlorides, temperature, crevices, deposits, process chemistry and cleaning conditions. A grade designation alone is not a service-life guarantee.
316
- General corrosion resistance comes from the chromium-rich passive film; nickel, molybdenum, nitrogen and copper change performance by grade.
- Check chlorides, temperature, crevices, deposits, process chemistry and cleaning conditions. A grade designation alone is not a service-life guarantee.
Fabrication and Heat Treatment
| Operation | 304 | 316 |
|---|---|---|
| Welding | Generally weldable with a qualified procedure and matching or over-alloyed filler where required; remove heat tint when corrosion service demands it. | Generally weldable with a qualified procedure and matching or over-alloyed filler where required; remove heat tint when corrosion service demands it. |
| Forming | Good ductility is typical, but rapid work hardening increases forming load and springback; bend radius and intermediate annealing depend on grade and reduction. | Good ductility is typical, but rapid work hardening increases forming load and springback; bend radius and intermediate annealing depend on grade and reduction. |
| Machining | Use rigid tooling, positive feeds and controlled heat because the material work-hardens; free-machining grades require separate corrosion and welding review. | Use rigid tooling, positive feeds and controlled heat because the material work-hardens; free-machining grades require separate corrosion and welding review. |
| Heat treatment | Solution annealing and rapid cooling restore the intended condition where applicable. Austenitic grades are not hardened by conventional quench-and-temper treatment. | Solution annealing and rapid cooling restore the intended condition where applicable. Austenitic grades are not hardened by conventional quench-and-temper treatment. |
Chemical Composition (wt%)
| Element | 304 | 316 |
|---|---|---|
| C | ≤0.08 | ≤0.08 |
| Mn | ≤2.00 | ≤2.00 |
| Si | ≤0.75 | ≤0.75 |
| Cr | 17.5–19.5 | 16.0–18.0 |
| Ni | 8.0–10.5 | 10.0–14.0 |
| P | ≤0.045 | ≤0.045 |
| S | ≤0.030 | ≤0.030 |
| N | ≤0.10 | — |
| Mo | — | 2.00–3.00 |
Mechanical Properties
| Property | 304 | 316 |
|---|---|---|
| Tensile strength | ≥515 MPa (75 ksi) | ≥515 MPa (75 ksi) |
| Yield strength (0.2%) | ≥205 MPa (30 ksi) | ≥205 MPa (30 ksi) |
| Elongation (50 mm) | ≥40% | ≥40% |
| Hardness | ≤201 HBW | ≤217 HBW |
Which One Should You Choose?
Choose 304 for:
- Indoor service: kitchens, food processing, appliances, furniture
- General architecture away from the coast
- Water tanks and plumbing with low chloride levels
- Budget-sensitive projects where the current delivered quotation favors 304
Choose 316 for:
- Coastal or marine exposure, including sea-front architecture
- Chemical, pharmaceutical and pulp processing equipment
- Swimming pool surrounds and de-icing salt exposure
- Any application with recurring chloride pitting or tea-staining
Our verdict
Default to 304 and upgrade to 316 the moment chlorides enter the picture. A useful rule: if the installation is within ~5 km of the sea, in contact with salt or chlorinated chemicals, or must stay cosmetically perfect outdoors, the molybdenum in 316 pays for itself. Otherwise 304 delivers the same strength and fabrication behavior at lower cost.
Cost and Availability
Compare the current stock position, mill route, minimum production quantity, processing yield, testing and delivered cost for 304 and 316 at quotation time. A fixed price ratio would be misleading because product form, size, condition and market timing can change the commercial result.
Do Not Substitute Without Review
Do not replace 304 with 316, or the reverse, from the grade name alone. Recheck chemistry, mechanical-property condition, product standard, dimensions, corrosion environment, welding procedure and project approval before substitution.
304 & 316 Products We Export
304 Stainless Steel Sheet
304/304L stainless steel sheet in 2B, BA, No.4 and mirror finish, in quotation-confirmed dimensions, cut to size, with ordered documentation.
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304 Stainless Steel Welded Pipe
304 welded stainless steel pipe and tube to ASTM A312, A249 and A554 — industrial, sanitary and polished decorative, round, square and rectangular sections.
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304 Stainless Steel Round Bar
304/304L stainless steel round bar, in quotation-confirmed dimensions, bright drawn h9/h11 or peeled, cut to length — machining stock with full heat traceability.
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316L Stainless Steel Sheet
316/316L stainless steel sheet for marine and chemical service, in quotation-confirmed dimensions in 2B, BA and brushed finishes, cut to size, with ordered documentation.
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Frequently Asked Questions
Is 316 stronger than 304?
No. Both grades share the same minimum mechanical properties in ASTM A240 (515 MPa tensile, 205 MPa yield). The premium buys corrosion resistance, not strength — if you need more strength, look at duplex 2205 instead.
How much more expensive is 316 than 304?
There is no durable percentage. Nickel, molybdenum, product form, dimensions, finish, processing and freight all move the delivered difference, so compare quotations for the same specification and date.
Can you visually tell 304 from 316?
No — they look identical in every finish. Verification requires the mill test certificate or a PMI (positive material identification) test with an XRF gun, which reads the molybdenum content directly.
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Technical content updated: 2026-07-29
Organizational author: Tsingshan (Shandong) Iron & Steel Co., Ltd..Review method, status and limitations.