AISI 316L Stainless Steel (UNS S31603): Marine-Grade Properties vs 317L Stainless Steel (UNS S31703): Properties, Corrosion Resistance & Applications
Side-by-side engineering comparison of AISI 316L Stainless Steel (UNS S31603): Marine-Grade Properties (ASTM A240/A276) and 317L Stainless Steel (UNS S31703): Properties, Corrosion Resistance & Applications (ASTM A240 / UNS S31703). Compare mechanical properties, chemical composition, density, yield strength, international equivalents, and typical applications to select the right material for your project.
Quick Verdict
316L stainless steel provides excellent corrosion resistance for marine, coastal, and chemical environments at moderate cost with PREN 24-28. 317L stainless steel offers higher molybdenum content (3-4% vs 2-3%) for PREN 29-33, providing significantly better resistance to chloride pitting and crevice corrosion in aggressive chemical processing environments. 317L costs 15-25% more than 316L. Choose 316L for general corrosion service; 317L for aggressive chloride environments where 316L insufficient.
Lower cost and wider availability for general corrosive service
Superior chloride pitting resistance for chemical processing and aggressive environments
Quick Comparison
| Property | AISI 316L Stainless Steel | 317L Stainless Steel (UNS |
|---|---|---|
| Standard | ASTM A240/A276 | ASTM A240 / UNS S31703 |
| Category | Stainless Steel | Stainless Steel |
| Density | 8.00 g/cm³ | 8.0 g/cm³ |
| Yield Strength | 170 MPa (25 ksi) | 205 MPa (30 ksi) |
| Tensile Strength | 485 MPa (70 ksi) | 515-690 MPa (75-100 ksi) |
| Key Applications | AISI 316L (UNS S31603) is a low-carbon (≤0.03%) austenitic stainless steel with 16-18% chromium, 10-14% nickel, and 2-3%... | 317L (UNS S31703) is a low-carbon austenitic stainless steel with 18-20% chromium, 11-15% nickel, and 3-4% molybdenum — ... |
International Equivalents
| AISI 316L Stainless Equivalents | 317L Stainless Steel Equivalents |
|---|---|
| EN 1.4404 | EN 1.4438 |
| X2CrNiMo17-12-2 | JIS SUS317L |
| SUS316L | GB 00Cr19Ni13Mo3 |
| 022Cr17Ni12Mo2 | — |
| AISI 316L | — |
How to Choose
| Choose AISI 316L Stainless Steel when... | 316L stainless steel provides excellent corrosion resistance for marine, coastal, and chemical environments at moderate cost with PREN 24-28. |
| Choose 317L Stainless Steel (UNS when... | 317L stainless steel offers higher molybdenum content (3-4% vs 2-3%) for PREN 29-33, providing significantly better resistance to chloride pitting and crevice corrosion in aggressive chemical processing environments. |
Decision Checklist: Which Is Right for You?
| Criterion | AISI 316L Stainless | 317L Stainless Steel |
|---|---|---|
| Lower Cost And Wider Availability For General Corrosive Service | ✓ | |
| Superior Chloride Pitting Resistance For Chemical Processing And Aggressive Environments | ✓ | |
| Higher yield strength | ✓ |
Frequently Asked Questions
What is the main difference between AISI 316L Stainless Steel (UNS and 317L Stainless Steel (UNS S317?
AISI 316L Stainless Steel (UNS S31603): Marine-Grade Properties (ASTM A240/A276) provides 170 MPa (25 ksi) yield strength at 8.00 g/cm³ density, while 317L Stainless Steel (UNS S31703): Properties, Corrosion Resistance & Applications (ASTM A240 / UNS S31703) delivers 205 MPa (30 ksi) at 8.0 g/cm³. The choice depends on whether your application prioritizes lower cost and wider availability for general corrosive service or superior chloride pitting resistance for chemical processing and aggressive environments.
Can AISI 316L Stainless Steel (UNS be substituted for 317L Stainless Steel (UNS S317?
In many applications, these materials can be cross-referenced, but direct substitution should always be verified against specific project specifications, especially for lower cost and wider availability for general corrosive service, superior chloride pitting resistance for chemical processing and aggressive environments, and operating environment. Consult your engineer of record.