astm a240 grade 316l (s31603) stainless steel plate supplier

ASTM A240 Grade 316L (S31603) Stainless Steel Plate

When you need a stainless steel that excels in welded structures and resists corrosion in chloride-rich or acidic environments without the hassle of post-weld annealing, ASTM A240 Grade 316L (S31603) stainless steel plate is the proven choice. We also call it A240 Gr 316L in the shop (Gr for Grade), A240 SS 316L (SS meaning stainless steel), A240 TP 316L (TP for tubing plate, common in piping specs), or simply AISI 316L plate (the longstanding American Iron and Steel Institute designation). Whatever you searched—whether for its low-carbon weldability or molybdenum-enhanced pitting resistance (PREN 24–26)—you're after a material that delivers 316’s corrosion performance with superior intergranular resistance in as-welded condition. At Gangsteel, we refine it via AOD + VOD for ultra-low carbon and clean inclusions, rolling plates up to 100 mm thick in finishes from 2B to mirror polish.

With over 25 years as a leading Chinese manufacturer and exporter, Gangsteel supplies ASTM A240 Grade 316L to pharmaceutical, marine, chemical, and food processing industries worldwide, fully certified to ASTM A240 and ASME SA240. This low-carbon austenitic grade (≤0.03% C) minimizes sensitization during welding, making it ideal for thick-section fabrications and sanitary applications. It offers nearly identical corrosion resistance to standard 316 but with greater weld integrity and cost-effective fabrication. Dive into our in-depth guide below. Explore our full ASTM A 240/A 240M stainless steel plate portfolio, including high-strength ASTM A 240 Gr 316 and high-temp ASTM A 240 Gr 316H.

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

ASTM A240 Grade 316L (UNS S31603) is a low-carbon, molybdenum-bearing austenitic stainless steel specified under ASTM A240 for plates, sheets, and strips in pressure vessels, welded tanks, and general corrosive service. The “L” stands for low carbon (≤0.03%), which prevents chromium carbide precipitation in the 425–870°C (800–1600°F) heat-affected zone (HAZ) during welding—eliminating the need for post-weld heat treatment in most cases. This makes A240 Gr 316L the go-to for fabricators building large welded structures like storage tanks, heat exchangers, and piping systems.

Developed in the 1950s to solve sensitization issues in 316 welds, 316L has become the standard for sanitary and chloride-exposed applications. At Gangsteel, we use argon-oxygen decarburization (AOD) followed by vacuum oxygen decarburization (VOD) to achieve carbon levels consistently below 0.025%, ensuring excellent resistance to intergranular corrosion (IGC) per ASTM A262 Practice E. With 16–18% Cr, 10–14% Ni, and 2–3% Mo, it forms a robust passive film that resists pitting and crevice corrosion in seawater, brines, and organic acids.

Users searching “A240 SS 316L” often value its hygienic properties: the smooth, non-porous surface meets FDA and 3-A sanitary standards, ideal for dairy, brewery, and pharmaceutical equipment. Its PREN of 24–26 gives it a critical pitting temperature (CPT) of ~25–35°C in 6% FeCl₃(ASTM G48), far superior to 304L (~15°C). Thermal conductivity (14.6 W/m·K) and expansion (16.5 ×10⁻⁶/°C) match well with other austenitics, reducing distortion in assemblies. Weld with 316L or 308L filler via GTAW/SMAW—no preheat, no anneal required for most joints.

Compared to ASTM A 240 Gr 304L, 316L offers 30–50% better chloride resistance, making it essential for coastal or chemical plants. For projects demanding weld reliability and long-term corrosion performance—like offshore platforms or food processing lines—A240 TP 316L delivers unmatched lifecycle value, often lasting 2–3x longer than carbon steel in aggressive environments.

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2. ASTM A240 Grade 316L Chemical Composition

The chemistry of ASTM A240 Grade 316L is precision-engineered for weldability and corrosion resistance, per Table 1. Gangsteel’s VOD process ensures carbon ≤0.025% and sulfur ≤0.010% for superior polishability and cleanliness.

The ultra-low carbon prevents Cr₂₃C₆formation, preserving grain boundary chromium. Molybdenum partitions to the passive film, dramatically improving resistance to localized corrosion. Our salt spray tests (ASTM B117) show <0.01 mm pitting after 2000 hours in 5% NaCl. Nitrogen adds minor solid-solution strengthening without compromising ductility.

Note: Unlike ASTM A 240 Gr 316, 316L avoids sensitization even in heavy welds. For nitrogen-boosted strength, see ASTM A 240 Gr 316LN. Mill test reports (MTRs) include full spectrographic analysis.

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3. ASTM A240 Grade 316L Mechanical Properties

Mechanical properties prioritize ductility and formability, tested per ASTM E8 in the annealed condition (1040°C min, water quench).

Lower yield than 316 (205 MPa) due to low carbon, but excellent for deep drawing and bending. Fatigue endurance ~200 MPa at 10⁷cycles. Charpy impact >120J at -196°C supports cryogenic use.

Compared to ASTM A 240 Gr 304LN, 316L has similar ambient strength but superior pitting resistance. Cold working can increase yield to 600+ MPa if needed.

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4. ASTM A240 Grade 316L Allowable Stress

Allowable stresses per ASME BPVC Section II Part D Table 1A ensure safe design.

Supports 8–10 bar at 300°C with <0.5% creep over 10,000 hours. For higher temps, consider ASTM A 240 Gr 316H. Certificates include full stress tables.

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5. ASTM A240 Grade 316L Equivalent Materials

Global equivalents ensure seamless sourcing.

Gangsteel offers dual-certified plates for ASME/EN compliance.

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6. ASTM A240 Grade 316L vs ASTM A 240 Gr 316, ASTM A 240 Gr 304L, and ASTM A 240 Gr 316Ti

In-depth comparison from Gangsteel’s testing vs ASTM A 240 Gr 316, ASTM A 240 Gr 304L, ASTM A 240 Gr 316Ti.

• Gr 316L vs 316: 316L’s low C prevents sensitization in welds (passes ASTM A262-E as-welded); 316 has higher strength but risks IGC without annealing—use 316L for heavy fabrication.
• Gr 316L vs 304L: 316L’s Mo doubles pitting resistance in chlorides (CPT 30°C vs 15°C); 304L cheaper for non-saline environments—our marine clients choose 316L for longevity.
• Gr 316L vs 316Ti: Both weldable; 316Ti’s Ti stabilizes against sensitization at 500–800°C, suiting heat exchangers; 316L simpler and cheaper for ambient welds.

Choose 316L for welded chloride service, 316 for strength, 304L for economy, 316Ti for hot welds.

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7. ASTM A240 Grade 316L Specifications

Gangsteel delivers with ±0.05 mm tolerances and full NDT options.

7.1 Plate and Sheet

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

7.2 Bar and Rod

• Diameter: 4–500 mm
• Length: Up to 12000 mm
• Finish: Peeled, ground, black
• Standards: ASTM A276, ASME SA479
• Uses: Fasteners, pump shafts

7.3 Custom Components

• Types: Flanges (B16.5), fittings, dished heads
• Processes: Laser cut, formed, welded
• Certs: NACE MR0175, PED 2014/68/EU, FDA
• Uses: Tailored for pharma and offshore

Inventory: 1000+ tons; 7–14 day global delivery.

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8. Applications of ASTM A240 Grade 316L

316L dominates in welded, corrosive, and sanitary environments:

• Pharmaceuticals: Vessels, piping; meets USP Class VI, no leachables.
• Food & Beverage: Tanks, conveyors; CIP-cleanable, FDA 21 CFR 177.
• Marine: Seawater piping, fittings; resists pitting in brines.
• Chemical: Storage for acids, chlorides; <0.05 mm/year in 20% H₂SO₄.
• Oil & Gas: Downhole tubing; SCC-resistant per NACE MR0175.

Vs ASTM A 240 Gr 321, 316L suits wet corrosives; 321 for high-temp stabilization.

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9. Price of ASTM A240 Grade 316L

As of November 2025, A240 Gr 316L prices range USD 3.0–4.0 per kg FOB Tianjin for standard hot-rolled plates (per metric ton: $3000–4000), per current market data, with cold-rolled and polished adding 15–25%. Molybdenum (2–3%) drives cost 20–30% above 304L; Ni at ~$17,000/ton adds volatility. Bulk orders >10 tons qualify for 10–15% discounts. Gangsteel offers LME-linked pricing and hedging.

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10. FAQ for ASTM A240 Grade 316L Stainless Steel Plate

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

A: Grade 316L has a maximum carbon content of 0.03% (vs ≤0.08% in 316), which prevents chromium carbide formation during welding, eliminating sensitization and the need for post-weld annealing in most cases; both offer identical pitting resistance (PREN 24–26), but 316L is preferred for welded structures, while 316 provides slightly higher strength (yield 205 vs 170 MPa) for non-welded parts.

Q: Is ASTM A240 Grade 316L food safe?

A: Yes, it is widely used in food and dairy processing; its smooth, non-porous surface resists bacterial adhesion, meets FDA 21 CFR 177.2600 and EU 1935/2004, and withstands CIP (clean-in-place) cycles with caustic and acid sanitizers without degradation—ideal for tanks, mixers, and conveyors.

Q: Can ASTM A240 Grade 316L be used in seawater?

A: Absolutely; its 2–3% molybdenum provides excellent resistance to pitting and crevice corrosion in seawater (CPT ~30°C), making it standard for marine platforms, desalination plants, and ship components; passivation per ASTM A380 enhances performance in high-chloride environments.

Q: What welding rod should I use for ASTM A240 Grade 316L?

A: Use ER316L or E316L filler metal for GTAW, GMAW, or SMAW; keep heat input low (0.8–1.5 kJ/mm) to minimize distortion and preserve corrosion resistance; no preheat or post-weld heat treatment is required, and the weld matches base metal properties per AWS A5.9.

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

A: Continuous service up to 870°C (1600°F) and intermittent to 925°C (1700°F); beyond this, scaling accelerates, and allowable stress drops significantly (e.g., 80 MPa at 500°C per ASME); for sustained high temperatures, consider 316H or stabilized grades like 321.

Q: Is ASTM A240 Grade 316L magnetic?

A: It is non-magnetic in the annealed condition due to its fully austenitic structure; however, heavy cold working (e.g., deep drawing) can induce 5–20% martensite, causing slight magnetism—full annealing at 1040°C restores non-magnetic properties.

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

A: Standard range is 0.3 mm to 100 mm for plates and 0.2 mm to 6 mm for sheets; widths up to 3000 mm and lengths to 12000 mm are common; custom thicknesses and cut-to-size pieces are available via waterjet, laser, or plasma cutting with tolerances as tight as ±0.05 mm.

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

A: 316L offers significantly better resistance to pitting and crevice corrosion in chloride environments (PREN 25 vs 19) due to molybdenum; 304L suffices for mild acids and atmospheric exposure but fails faster in brines or seawater—316L is the choice for marine, chemical, and pharmaceutical applications.

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11. Why Choose Gangsteel?

With roots since 1998, Gangsteel’s 500+ experts and in-house labs deliver unmatched E-E-A-T. We export 100,000 tons annually, holding ABS, DNV, and TUV certifications. For 316L: 100% PMI/UT tested, EN 10204 3.2 certs, 7-day expedited delivery. Explore ASTM A 240 Gr 321H. Trusted by Pfizer, Shell, and Samsung.

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12. Conclusion

ASTM A240 Grade 316L (S31603) from Gangsteel is the weld-friendly, chloride-resistant workhorse of austenitic stainless steels, its low-carbon design and molybdenum armor conquering pharma, marine, and chemical challenges. With global equivalents like EN X2CrNiMo17-12-2 and robust as-welded performance, at $3.0–4.0/kg in November 2025, it’s engineered value. Contact us for quotes, samples, or data sheets on this or ASTM A 240 Gr 304H. Build to last with Gangsteel.