What is ASTM A240 316L stainless steel material?

What is ASTM A240 316L material?

When materials specialists, engineers, or buyers ask "What is ASTM A240 316L material?", they're referring to ASTM A240 Grade 316L (UNS S31603), a low-carbon, molybdenum-bearing austenitic stainless steel plate, sheet, or strip optimized for enhanced corrosion resistance in chloride and acidic environments, with superior weldability to avoid intergranular corrosion (IGC) without post-weld annealing.

ASTM A240/A240M is the specification for chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and general applications, and Grade 316L is the low-carbon variant of 316, with carbon capped at ≤0.03% to prevent carbide precipitation in the heat-affected zone (HAZ) during welding. As a leading manufacturer and exporter in China, Gangsteel produces ASTM A240 316L material, certified to both ASTM A240 and ASME SA240, with a focus on low carbon for weld integrity and molybdenum for a PREN (Pitting Resistance Equivalent Number) of 24-26, making it ideal for marine, chemical, and pharmaceutical uses.

ASTM A240 316L is non-magnetic in the annealed state, offers good strength (yield ≥170 MPa), and excels in formability for deep drawing or bending, with resistance to atmospheric corrosion, dilute acids, and food acids. At Gangsteel, we refine 316L through argon-oxygen decarburization (AOD) and vacuum oxygen decarburization (VOD) for carbon below 0.025% and minimal inclusions, delivering plates up to 100 mm thick in finishes like 2B, BA, and electropolished. Priced at USD 5-8/kg in November 2025, it's a premium upgrade from 304L for chloride-prone settings but more economical than super-austenitics. This comprehensive guide details its composition, properties, and more. For our molybdenum-bearing lineup, explore the ASTM A 240/A 240M stainless steel plate portfolio, including ASTM A 240 Gr 316L and high-carbon ASTM A 240 Gr 316H.

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1. What is A240 Grade 316L (S31603)?

ASTM A240 Grade 316L (UNS S31603) is a low-carbon, molybdenum-enhanced austenitic stainless steel under ASTM A240/A240M, tailored for superior corrosion resistance in aggressive environments like chlorides, acids, and seawater, while providing excellent weldability for as-welded structures without annealing. The "L" signifies low carbon (≤0.03%), which minimizes chromium carbide formation in the 425-870°C HAZ during welding, preventing sensitization and IGC—making it the preferred choice for thick-section fabrications in pressure vessels, tanks, and piping.

Developed as a weld-optimized version of 316 in the mid-20th century, 316L addresses issues like weld decay in chemical and marine industries. At Gangsteel, we produce it from premium melts with VOD for carbon <0.025% and inclusions <0.01%, achieving grain size ASTM 6-8 for ductility. The austenitic structure—16-18% Cr, 10-14% Ni, 2-3% Mo—ensures non-magnetic status, high toughness (Charpy >120J at -196°C), and formability for complex shapes like dished heads. Thermal conductivity is 14.6 W/m·K at 100°C, with expansion 16.5 × 10⁻⁶/°C for stable assemblies.

Commonly known as "AISI 316L plate," it welds with 316L filler without preheat, passing bend tests per ASTM A240. Compared to ASTM A 240 Gr 316 (C ≤0.08%), 316L trades minor strength for superior weld IGC resistance. For stabilized versions, see ASTM A 240 Gr 316Ti.

In pharma vessels or offshore piping, A240 316L's durability cuts maintenance 40-60% vs 304L in brines, based on our European client feedback.

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2. A240 Grade 316L Chemical Composition

The chemistry of A240 Grade 316L is precision-tuned for weldability and corrosion, per ASTM A240 Table 1.

Low C prevents Cr23C6 in HAZ; Mo enhances film vs chlorides. N ≤0.10% adds strength. Gangsteel keeps C <0.025%, S <0.01% for polishability, with <0.05 mm/year in sulfuric.

Note: Vs ASTM A 240 Gr 316H (high C), 316L for welds not creep. MTRs with spectro.

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3. A240 Grade 316L Mechanical Properties

Mechanics of A240 Grade 316L emphasize ductility, annealed at 1010-1120°C.

Low C yields softer than 316 (yield 205 MPa); excellent for stamping. Fatigue ~220 MPa at 10^7 cycles. Charpy >120J at -196°C.

Vs ASTM A 240 Gr 304L, similar ambient but Mo for corrosives.

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4. A240 Grade 316L Allowable Stress

Stresses per ASME BPVC Table 1A.

Mo for 8 bar at 300°C. For hotter, ASTM A 240 Gr 316H. Certs with tables.

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5. A240 Grade 316L Equivalent Materials

Equivalents for global use.

Gangsteel dual-certs.

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6. A240 Grade 316L vs A240 Gr 316, A240 Gr 304L, and A240 Gr 316Ti

Vs ASTM A 240 Gr 316, ASTM A 240 Gr 304L, ASTM A 240 Gr 316Ti.

• 316L vs 316: 316L low C for welds (A262 pass as-welded); 316 higher strength for non-weld.
• 316L vs 304L: 316L Mo for chlorides (CPT 30°C vs 15°C); 304L cheaper for mild.
• 316L vs 316Ti: 316Ti Ti for heat stab; 316L simpler for ambient welds.

Choose 316L for welded corrosives, 316 strength, 304L economy, 316Ti heat stab.

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7. A240 Grade 316L Specifications

Gangsteel delivers with ±0.05 mm and full NDT.

7.1 Plate and Sheet

• Thickness: 0.3-100 mm (plate), 0.2-6 mm (sheet)
• Width: 1000-3000 mm
• Length: 2000-12000 mm/coils
• Surface: 2B, BA, No.4, 8K; electropolished Ra <0.4 μm
• Standards: ASTM A240, ASME SA240, AMS 5507
• Uses: Plates for reactors, sheets for cladding

7.2 Bar and Rod

• Diameter: 4-500 mm
• Length: Up to 12000 mm
• Finish: Peeled, ground
• Standards: ASTM A276, ASME SA479
• Uses: Bolts, shafts

7.3 Custom Components

• Types: Flanges, fittings
• Processes: CNC, welded
• Certs: NACE, PED, FDA
• Uses: Pharma, marine

1000 tons stock; 7-14 days.

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8. Applications of A240 Grade 316L

316L dominates in welded corrosives:

• Pharma: Vessels; USP Class VI, sterile.
• Food: Tanks; CIP, FDA 21 CFR 177.
• Marine: Piping; seawater pitting resistant.
• Chemical: Storage; sulfuric/phosphoric <0.05 mm/year.
• Oil & Gas: Downhole; SCC per NACE MR0175.

Vs 304L, 316L for salts.

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9. Price of A240 Grade 316L

November 2025: USD 5-8/kg FOB, hot-rolled $5.5/kg, cold $7/kg, per trends. Mo/Ni ~$17k/ton volatile; 30% over 304L. Gangsteel discounts bulk.

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10. FAQ for A240 Grade 316L Stainless Steel Material

Q: What is the difference between A240 316L and 316?

A: A240 316L has lower carbon (≤0.03% vs ≤0.08% in 316), preventing sensitization and IGC in welds without annealing; both share Mo for corrosion (PREN 25), but 316L is preferred for heavy fabrication, while 316 offers slightly higher strength for non-weld loads.

Q: Is A240 316L food grade?

A: Yes; compliant with FDA 21 CFR 177 and EU 1935/2004, its smooth surface resists bacterial adhesion and withstands CIP with caustics/acids—ideal for dairy tanks and pharma vessels.

Q: Can A240 316L be used in seawater?

A: Yes; Mo provides excellent pitting resistance (CPT ~30°C), making it standard for marine piping and desalination; passivate per A380 for longevity in high-chloride.

Q: What welding rod for A240 316L?

A: ER316L or E316L; low heat input (0.8-1.5 kJ/mm) preserves resistance; no preheat/anneal needed—the weld matches base for corrosion.

Q: What is the maximum service temperature for A240 316L?

A: Continuous 870°C, intermittent 925°C; beyond, scaling accelerates, stress drops (80 MPa at 500°C per ASME)—for sustained heat, use 316H.

Q: Is A240 316L magnetic?

A: Non-magnetic annealed; cold work induces slight (5-20% martensite)—anneal at 1040°C to restore.

Q: What thicknesses are available for A240 316L plates?

A: 0.3-100 mm plates, 0.2-6 mm sheets; widths to 3000 mm, custom cuts ±0.05 mm.

Q: How does A240 316L compare to 304L in corrosion?

A: 316L superior in chlorides (PREN 25 vs 19) due to Mo; 304L for mild—316L for marine/chem.

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11. Why Choose Gangsteel?

Gangsteel’s 25+ years, 500+ experts deliver E-E-A-T. 120k tons/year, ABS/TUV certified. For 316L: 100% PMI, low C custom, global ship. Explore ASTM A 240 Gr 304L.

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12. Conclusion

ASTM A240 316L material is the low-carbon, Mo-enhanced austenitic stainless for welded corrosion resistance in pharma, marine, and chemical. With equivalents like EN 1.4404 and mechanics for durability, at $5-8/kg in 2025, it’s premium value. Contact Gangsteel for quotes or data on this or ASTM A 240 Gr 304H. Innovate with integrity.