Distinguished by its molybdenum-enhanced corrosion resistance, 316 stainless steel sheet is the workhorse alloy for demanding environments where standard 304 fails. Its key advantage lies in chloride resistance, making it essential for marine, chemical, and hygienic applications.
Core Performance Drivers (vs. 304):
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2-3% Molybdenum (Mo): Critical for pitting/crevice corrosion resistance.
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Low Carbon Variant (316L): Prevents weld decay (≤0.03% C).
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Non-Magnetic (Annealed): Suitable for sensitive electronic environments.
1. Critical Selection Parameters & Tolerances
| Parameter | 316 / 316L Value Range | Key Standard | Tolerance Focus (e.g., ASTM A480) |
| PREN<sup>*</sup> | 24-28 | N/A | *Critical corrosion index (Cr + 3.3Mo + 16N)* |
| Thickness (mm/in) | 0.3-6.0 / 0.012-0.236 | ASTM A480 | ±0.02mm (precision) to ±10% (HR) |
| Width (mm/in) | 1000-2000 / 39-79 | EN 10029 | +5/-0 mm (slit edge), +10/-0 mm (mill) |
| Flatness (mm/m) | ≤3 (Cold Rolled) | ASTM A480 | Varies by thickness & width |
| Surface Ra (μm) | 0.1-0.5 (2B), <0.2 (BA) | ISO 4287 | Critical for hygiene & adhesion |
<sup></sup>Pitting Resistance Equivalent Number – higher = better chloride resistance.*
2. Specification Matrix: Standards x Key Requirements
| Standard | Grade | Key Focus Area | Mandatory Test (Example) |
| ASTM A240 | S31600/S31603 | Pressure Vessels & Gen. App | Pitting Corrosion (ASTM G48) |
| EN 10088-2 | 1.4401/1.4404 | Construction & EU Compliance | Intergranular Corrosion (ISO 3651-2) |
| JIS G4305 | SUS 316/SUS316L | Japanese Industrial Machinery | Ferrite Content (JIS G 0567) |
| ASME SA-240 | S31600/S31603 | Boiler & Pressure Vessel Code | Hydrostatic / Ultrasonic Testing |
| ISO 9328-2 | P316L | Int'l Pressure Equipment | Impact Toughness (-196°C) |
3. Global Equivalents & Proprietary Grades
| Region | Standard Grade | Low Carbon (L) | Stabilized (Ti) | High-Performance Variant |
| Global | UNS S31600 | UNS S31603 | UNS S31635 | UNS S31653 (High N) |
| Europe | 1.4401 (X5CrNiMo17-12-2) | 1.4404 | 1.4571 | 1.4436 (Higher Mo+N) |
| Japan | SUS 316 | SUS 316L | SUS 316Ti | SUS 316J1L (N added) |
| China | 06Cr17Ni12Mo2 | 022Cr17Ni12Mo2 | 07Cr17Ni12Mo2Ti | 015Cr21Ni26Mo5Cu2 (Super) |
| India | 316S31 | 316S33 | 316S41 | - |
4. Advanced Packaging Protocols
| Protection Level | Method | Industries Served | Cost Impact |
| Basic | VCI paper interleaving + steel strapping | General Manufacturing | +0% |
| Marine Grade | Double PE coating + desiccant packs | Offshore, Shipbuilding | +12-15% |
| Hygienic | Peelable PVF film + inert gas flush | Pharma, Semiconductor | +20-30% |
| High-Abrasion | Corner guards + plywood crate lining | Automotive Tooling | +8-10% |
| Export Heavy | Steel-reinforced timber crate | Mining, Remote Projects | +15-25% |
5. Specialized Applications & Alloy Selection Logic
| Industry | Critical Requirement | 316 Subtype | Why Not 304? | Competing Material |
| Desalination | Saltwater pitting @ 60°C+ | 316L (2.5% Mo min) | PREN <20 insufficient | 6% Mo alloys |
| Bioprocessing | CIP/SIP corrosion + purity | 316L Mirror (#8) | Surface imperfections | Electropolished 316L |
| Coastal Architecture | Salt spray + aesthetic | 316 HL finish | Surface rust staining | 2205 Duplex |
| Chemical Tankers | Cargo vapor corrosion | 316Ti | Sensitization at welds | Hastelloy |
| Marine Fasteners | Crevice corrosion | 316L (Cold worked) | Galvanic pitting | Titanium |
6. Technical Specification Snapshot
| Property | 316 (Annealed) | 316L (Annealed) | 316 (1/2 Hard) | Test Method |
| 0.2% Proof (MPa) | 205 min | 170 min | 550 min | ASTM E8/E21 |
| UTS (MPa) | 515 min | 485 min | 860 min | ASTM E8/E21 |
| Elongation (%) | 40 | 40 | 12 | ASTM E8 (50mm GL) |
| Thermal Conductivity (W/m·K) | 16.3 @100°C | 16.3 @100°C | 16.3 @100°C | ASTM C177 |
| CTE (μm/m·°C) | 16.0 (20-100°C) | 16.0 (20-100°C) | 16.0 (20-100°C) | ASTM E228 |
| Magnetic Permeability | <1.02 μ | <1.02 μ | <1.10 μ | ASTM A342 |
Key Differentiation from Standard 304:
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Chloride Threshold: 316 withstands 200-1000 ppm Cl<sup>-</sup> vs. 304's 50-100 ppm
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Pitting Temperature: 316 resists up to 25°C in 6% FeCl<sub>3</sub> vs. 304's 10°C
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Cost Premium: Typically 20-40% over 304, justified in corrosive service
Procurement Tip: Specify Mo content ≥2.1% for marine applications and verify mill certifications meet NACE MR0175/ISO 15156 for sour service. Always opt for 316L for welded fabrications to avoid intergranular corrosion.
