Marine-Grade Molybdenum-Bearing Austenitic Stainless Steel Seamless, Welded & ERW Pipes and Heat Exchanger Tubes
Om Export India Pvt Ltd is an internationally recognized manufacturer, stockist, and global exporter of high-performance Stainless Steel 316 Pipes and Tubes (ASTM A312 TP316 / UNS S31600 / Werkstoff 1.4401). Grade 316 is the benchmark molybdenum-bearing austenitic stainless steel, containing 16.0% to 18.0% Chromium, 10.0% to 14.0% Nickel, and 2.0% to 3.0% Molybdenum. The addition of molybdenum significantly enhances pitting and crevice corrosion resistance in aggressive chloride, bromide, and marine environments compared to standard 304-series steels.
Widely designated as marine-grade stainless steel, our 316 seamless and welded piping systems are manufactured strictly in compliance with ASTM A312, ASTM A213, ASTM A269, and ASME Section II standards. Operating with a density of 8.00 g/cm³ and a melting point of 1400°C (2500°F), SS 316 delivers superior creep strength, high rupture toughness, and exceptional fatigue performance under elevated temperatures up to 870°C (1600°F). These pipes and tubes serve mission-critical applications across marine seawater cooling, offshore oil and gas production, chemical reactors, pulp and paper bleach plants, and pharmaceutical distillation systems.
| Specification Parameter | Standard Specification / Technical Value |
|---|---|
| Nominal Size Range (Seamless) | 1/8" NB to 24" NB (Outer Diameter: 6.00 mm to 609.6 mm OD) |
| Nominal Size Range (Welded / ERW / EFW) | 1/8" NB to 100" NB (Outer Diameter: 6.00 mm to 2540.0 mm OD) |
| Wall Thickness & Schedules | 0.30 mm to 50.0 mm (SCH 5S, SCH 10S, SCH 40S/STD, SCH 80S/XS, SCH 120, SCH 160, SCH XXS) |
| Governing Standards | ASTM A312 / ASME SA312, ASTM A213, ASTM A269, ASTM A249, ASTM A358, ASTM A376, ASTM A554 |
| Manufacturing Methods | Cold Drawn Seamless (CDS), Hot Finished Seamless, High-Frequency Induction ERW, Plasma/TIG Welded, LSAW |
| Heat Treatment & Delivery State | Solution Annealed at 1040°C – 1150°C followed by rapid quenching; Bright Annealed (BA) |
| Standard Lengths | Single Random Length (SRL), Double Random Length (DRL), Custom Cut Lengths up to 26,000 mm (26m) |
| End Configurations & Protection | Plain Square Cut End (PE), Beveled End (BE 30°/37.5° per ASME B16.25), Threaded Ends with Plastic End Caps |
| Nominal Pipe Size (NPS) | Outside Diameter (OD mm / in.) | Wall Thickness (WT mm / in.) | Nominal Schedule | Nominal Weight (kg/m) | Nominal Weight (lb/ft) |
|---|---|---|---|---|---|
| 1/2" NB | 21.34 mm (0.840") | 1.65 mm (0.065") | SCH 10S | 0.81 kg/m | 0.54 lb/ft |
| 1/2" NB | 21.34 mm (0.840") | 2.77 mm (0.109") | SCH 40S / STD | 1.29 kg/m | 0.85 lb/ft |
| 1/2" NB | 21.34 mm (0.840") | 3.73 mm (0.147") | SCH 80S / XS | 1.65 kg/m | 1.09 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 1.65 mm (0.065") | SCH 10S | 1.03 kg/m | 0.69 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 2.87 mm (0.113") | SCH 40S / STD | 1.71 kg/m | 1.13 lb/ft |
| 3/4" NB | 26.67 mm (1.050") | 3.91 mm (0.154") | SCH 80S / XS | 2.23 kg/m | 1.48 lb/ft |
| 1" NB | 33.40 mm (1.315") | 1.65 mm (0.065") | SCH 5S | 1.31 kg/m | 0.88 lb/ft |
| 1" NB | 33.40 mm (1.315") | 2.77 mm (0.109") | SCH 10S | 2.13 kg/m | 1.43 lb/ft |
| 1" NB | 33.40 mm (1.315") | 3.38 mm (0.133") | SCH 40S / STD | 2.54 kg/m | 1.68 lb/ft |
| 1" NB | 33.40 mm (1.315") | 4.55 mm (0.179") | SCH 80S / XS | 3.29 kg/m | 2.17 lb/ft |
| 1-1/4" NB | 42.16 mm (1.660") | 2.77 mm (0.109") | SCH 10S | 2.73 kg/m | 1.83 lb/ft |
| 1-1/4" NB | 42.16 mm (1.660") | 3.56 mm (0.140") | SCH 40S / STD | 3.44 kg/m | 2.31 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 2.77 mm (0.109") | SCH 10S | 3.16 kg/m | 2.12 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 3.68 mm (0.145") | SCH 40S / STD | 4.11 kg/m | 2.72 lb/ft |
| 1-1/2" NB | 48.26 mm (1.900") | 5.08 mm (0.200") | SCH 80S / XS | 5.49 kg/m | 3.63 lb/ft |
| 2" NB | 60.33 mm (2.375") | 2.77 mm (0.109") | SCH 10S | 3.99 kg/m | 2.64 lb/ft |
| 2" NB | 60.33 mm (2.375") | 3.91 mm (0.154") | SCH 40S / STD | 5.52 kg/m | 3.66 lb/ft |
| 2" NB | 60.33 mm (2.375") | 5.54 mm (0.218") | SCH 80S / XS | 7.60 kg/m | 5.03 lb/ft |
| 2-1/2" NB | 73.03 mm (2.875") | 3.05 mm (0.120") | SCH 10S | 5.35 kg/m | 3.59 lb/ft |
| 2-1/2" NB | 73.03 mm (2.875") | 5.16 mm (0.203") | SCH 40S / STD | 8.77 kg/m | 5.89 lb/ft |
| 3" NB | 88.90 mm (3.500") | 3.05 mm (0.120") | SCH 10S | 6.56 kg/m | 4.34 lb/ft |
| 3" NB | 88.90 mm (3.500") | 5.49 mm (0.216") | SCH 40S / STD | 11.47 kg/m | 7.58 lb/ft |
| 3" NB | 88.90 mm (3.500") | 7.62 mm (0.300") | SCH 80S / XS | 15.51 kg/m | 10.26 lb/ft |
| 4" NB | 114.30 mm (4.500") | 3.05 mm (0.120") | SCH 10S | 8.50 kg/m | 5.62 lb/ft |
| 4" NB | 114.30 mm (4.500") | 6.02 mm (0.237") | SCH 40S / STD | 16.32 kg/m | 10.80 lb/ft |
| 4" NB | 114.30 mm (4.500") | 8.56 mm (0.337") | SCH 80S / XS | 22.67 kg/m | 15.00 lb/ft |
| 6" NB | 168.28 mm (6.625") | 3.40 mm (0.134") | SCH 10S | 14.04 kg/m | 9.30 lb/ft |
| 6" NB | 168.28 mm (6.625") | 7.11 mm (0.280") | SCH 40S / STD | 28.69 kg/m | 18.99 lb/ft |
| 6" NB | 168.28 mm (6.625") | 10.97 mm (0.432") | SCH 80S / XS | 43.21 kg/m | 28.60 lb/ft |
| 8" NB | 219.08 mm (8.625") | 3.76 mm (0.148") | SCH 10S | 20.27 kg/m | 13.62 lb/ft |
| 8" NB | 219.08 mm (8.625") | 8.18 mm (0.322") | SCH 40S / STD | 43.20 kg/m | 28.55 lb/ft |
| 8" NB | 219.08 mm (8.625") | 12.70 mm (0.500") | SCH 80S / XS | 65.63 kg/m | 43.39 lb/ft |
| Element | ASTM A312 TP316 (%) | UNS S31600 (%) | DIN 1.4401 / X5CrNiMo17-12-2 (%) |
|---|---|---|---|
| Carbon (C, Max) | 0.08 | 0.08 | 0.07 |
| Chromium (Cr) | 16.00 – 18.00 | 16.00 – 18.00 | 16.50 – 18.50 |
| Nickel (Ni) | 10.00 – 14.00 | 10.00 – 14.00 | 10.00 – 13.00 |
| Molybdenum (Mo) | 2.00 – 3.00 | 2.00 – 3.00 | 2.00 – 2.50 |
| Manganese (Mn, Max) | 2.00 | 2.00 | 2.00 |
| Silicon (Si, Max) | 0.75 (1.00 Max) | 0.75 | 1.00 |
| Phosphorus (P, Max) | 0.045 | 0.045 | 0.045 |
| Sulfur (S, Max) | 0.030 | 0.030 | 0.015 |
| Nitrogen (N, Max) | 0.10 | 0.10 | 0.10 |
| Iron (Fe) | Balance | Balance | Balance |
| Mechanical Property | ASTM A312 TP316 Specified Limits | Typical Production Values |
|---|---|---|
| Tensile Strength, Ultimate (Min) | 515 MPa (75 ksi / 75,000 psi) | 560 – 620 MPa |
| Yield Strength (0.2% Proof, Min) | 205 MPa (30 ksi / 30,000 psi) | 240 – 290 MPa |
| Elongation in 2 in. / 50 mm (Min) | 35% – 40% Min | 45% – 55% |
| Hardness (Rockwell B / Brinell, Max) | 95 HRB Max / 217 HBW Max | 82 – 88 HRB (155 – 185 HBW) |
| Density & Melting Point | Density: 8.00 g/cm³ (8000 kg/m³) | Melting Point: 1400°C (2500°F) |
| Modulus of Elasticity | 193 GPa (28 x 10⁶ psi) | Poisson's Ratio: 0.28 – 0.30 |
| Thermal Expansion (0–100°C / 0–538°C) | 15.9 µm/m·°C (0–100°C) | 17.5 µm/m·°C (0–538°C) |
| Thermal Conductivity & Resistivity | 16.3 W/m·K at 100°C | Electrical Resistivity: 740 nΩ·m |
| Standard Designation | Governing Organization | Scope & Product Description |
|---|---|---|
| ASTM A312 / ASME SA312 | ASTM / ASME | Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes (TP316 / UNS S31600) |
| ASTM A213 / ASME SA213 | ASTM / ASME | Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes (TP316) |
| ASTM A269 / ASME SA269 | ASTM / ASME | Seamless and Welded Austenitic Stainless Steel Tubing for General Marine & Corrosive Service |
| ASTM A249 / ASME SA249 | ASTM / ASME | Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes |
| ASTM A358 / ASME SA358 | ASTM / ASME | Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature Service |
| ASTM A376 / ASME SA376 | ASTM / ASME | Seamless Austenitic Steel Pipe for High-Temperature Central-Station Power Service |
| ASTM A409 / ASME SA409 | ASTM / ASME | Welded Large Diameter Austenitic Light-Wall Steel Pipe for Corrosive or High-Temperature Service |
| EN 10216-5 / DIN 17456 / 17458 | European / German Standards | Seamless Steel Tubes for Pressure Purposes (Grade 1.4401 / X5CrNiMo17-12-2) |
| Indian Boiler Regulations (IBR) | Central Boilers Board | IBR Certified Steam and High-Pressure Stainless Steel Boiler Piping |
Stainless Steel 316 marine-grade pipes and tubes are utilized across severe chloride, chemical, and elevated-temperature process systems:
Q1: Why is Stainless Steel 316 classified as “Marine Grade” stainless steel?
Stainless Steel 316 contains 2.0% to 3.0% Molybdenum, which drastically increases its Pitting Resistance Equivalent Number (PREN) compared to 304. This enables it to resist pitting and crevice corrosion caused by sodium chloride in ocean spray, brackish water, and marine atmospheres.
Q2: What is the main operational difference between SS 316 and SS 316L?
SS 316 has a higher allowable carbon limit (≤0.08%), which provides slightly higher creep and tensile strength at elevated operating temperatures. SS 316L restricts carbon to ≤0.030% to prevent chromium carbide precipitation during welding, making 316L preferred for heavy-gauge welded assemblies that cannot undergo post-weld annealing.
Q3: What are the pressure capabilities of ASTM A312 TP316 Schedule 40 and 80 pipes?
ASTM A312 TP316 Schedule 40 pipes provide cold working pressure ratings up to 3048 psig (for 1″ size) and 1902 psig (for 2″ size) at 100°F. For higher pressure service, Schedule 80 and 160 configurations are utilized, designed in accordance with ASME B31.3 process piping allowable stresses.
Q4: What certifications and NDT tests accompany Om Export India Pvt Ltd SS 316 shipments?
Every consignment includes EN 10204 Type 3.1 / 3.2 Material Test Certificates, IBR Form III-D / III-A statutory documents, 100% Positive Material Identification (PMI) spectro analysis, 100% hydrostatic testing, and automated Eddy Current / Ultrasonic testing reports.
Contact OM Export India for pricing, technical support, stock availability and export enquiries.