Metinox Overseas stands as India's most trusted manufacturer and global exporter of ASTM A403 WP316 pipe fittings, delivering uncompromising quality since our inception. Our WP316 buttweld fittings are engineered to meet the most demanding industrial applications across oil & gas, petrochemical, pharmaceutical, and power generation sectors worldwide.
With ISO 9001:2015 certification and state-of-the-art manufacturing facilities in Mumbai, we produce a comprehensive range of 316-grade fittings including elbows, tees, reducers, caps, and stub ends that conform to ASTM A403, ASME B16.9, and MSS-SP-43 standards. Every fitting undergoes rigorous quality testing including PMI, radiography, and hydrostatic testing to ensure superior corrosion resistance, mechanical strength, and dimensional accuracy.
Our technical team brings over 25 years of metallurgical expertise, ensuring each product meets exact specifications for seamless integration into critical piping systems. Whether you need standard Schedule 40 fittings or custom-engineered solutions, Metinox Overseas delivers fast turnaround, competitive pricing, and certified documentation that keeps your projects on schedule. All fittings are supplied with EN 10204 3.1 material test certificates; 3.2 certification and third-party inspection (TÜV, Lloyd's, BV, DNV, SGS) are available on request.
Request a quote nowASTM A420 WPL6 identifies wrought carbon steel pipe fittings for low-temperature service. WPL6 is selected where the design requires carbon steel fittings with verified Charpy V-notch impact toughness at -50°F (-45.6°C). It is commonly specified with ASTM A333 Grade 6 pipe and ASTM A350 LF2 flanges in low-temperature piping systems.
These fittings are manufactured through hot or cold forming processes, followed by solution annealing and pickling to achieve optimal mechanical properties and surface finish. Unlike cast fittings, wrought fittings offer superior strength, ductility, and weldability.
| Element | Min % | Max % |
|---|---|---|
| Carbon (C) | — | 0.08 |
| Manganese (Mn) | — | 2.00 |
| Phosphorus (P) | — | 0.045 |
| Sulfur (S) | — | 0.030 |
| Silicon (Si) | — | 1.00 |
| Chromium (Cr) | 16.00 | 18.00 |
| Nickel (Ni) | 10.00 | 14.00 |
| Molybdenum (Mo) | 2.00 | 3.00 |
| Nitrogen (N) | — | 0.10 |
| Iron (Fe) | — | Balance |
Note: UNS S31600. Nickel range 10.0–14.0% per ASTM A403 Table 1. On pierced tubing, the nickel range may be 11.0–16.0%. (This footnote prevents supplier disputes on pierced-tube material certificates.)
Sensitization Advisory: 316 SS is susceptible to sensitization (intergranular carbide precipitation) at temperatures of 425–870°C. Specify 316L for welded assemblies not subject to post-weld solution annealing.
| Property | Value |
|---|---|
| Tensile Strength | 515 MPa (min) |
| Yield Strength (0.2% Offset) | 205 MPa (min) |
| Elongation in 50mm | 35% (min) per ASTM A403 Table 3 for WP316 |
| Hardness (Brinell) | 217 HBW (max) |
| Density | 8.00 g/cm³ |
| Melting Point | 1400°C – 1450°C |
| Standard | Grade Designation |
|---|---|
| UNS | S31600 |
| EN/DIN | 1.4401 / X5CrNiMo17-12-2 |
| BS | 316S31 |
| JIS | SUS 316 |
| AFNOR | Z7CND17-11-02 |
| GOST | 08Х17Н13М2 |
| Size (NB) | Outside Diameter (mm) | Center to End (mm) | Sch 40S Weight (kg) | Sch 80S Weight (kg) |
|---|---|---|---|---|
| ½" | 21.3 | 38 | 0.05 | 0.07 |
| ¾" | 26.7 | 38 | 0.08 | 0.11 |
| 1" | 33.4 | 38 | 0.11 | 0.16 |
| 1¼" | 42.2 | 48 | 0.17 | 0.25 |
| 1½" | 48.3 | 57 | 0.23 | 0.34 |
| 2" | 60.3 | 76 | 0.40 | 0.59 |
| 2½" | 73.0 | 95 | 0.66 | 0.97 |
| 3" | 88.9 | 114 | 1.02 | 1.50 |
| 4" | 114.3 | 152 | 1.85 | 2.72 |
| 6" | 168.3 | 229 | 5.20 | 7.65 |
| 8" | 219.1 | 305 | 10.50 | 15.42 |
| 10" | 273.1 | 381 | 18.20 | 26.75 |
| 12" | 323.9 | 457 | 28.50 | 41.85 |
| Size (NB) | Outside Diameter (mm) | Center to End (mm) | Sch 40S Weight (kg) | Sch 80S Weight (kg) |
|---|---|---|---|---|
| ½" | 21.3 | 25 | 0.06 | 0.09 |
| ¾" | 26.7 | 29 | 0.10 | 0.14 |
| 1" | 33.4 | 32 | 0.14 | 0.21 |
| 1½" | 48.3 | 48 | 0.38 | 0.56 |
| 2" | 60.3 | 51 | 0.62 | 0.91 |
| 3" | 88.9 | 64 | 1.52 | 2.23 |
| 4" | 114.3 | 76 | 2.75 | 4.04 |
| 6" | 168.3 | 102 | 7.75 | 11.39 |
| 8" | 219.1 | 127 | 15.65 | 23.00 |
| 10" | 273.1 | 152 | 27.15 | 39.88 |
| 12" | 323.9 | 178 | 42.50 | 62.45 |
| Size (NB) | Large End OD (mm) | Small End OD (mm) | Length (mm) | Sch 40S Weight (kg) |
|---|---|---|---|---|
| 1" x ½" | 33.4 | 21.3 | 51 | 0.08 |
| 1½" x 1" | 48.3 | 33.4 | 64 | 0.15 |
| 2" x 1" | 60.3 | 33.4 | 76 | 0.24 |
| 3" x 2" | 88.9 | 60.3 | 89 | 0.58 |
| 4" x 3" | 114.3 | 88.9 | 102 | 1.05 |
| 6" x 4" | 168.3 | 114.3 | 127 | 2.85 |
| 8" x 6" | 219.1 | 168.3 | 152 | 5.70 |
| 10" x 8" | 273.1 | 219.1 | 191 | 10.85 |
| 12" x 10" | 323.9 | 273.1 | 203 | 16.75 |
Complete dimensional charts for all sizes and schedules available upon request.
| Certification | Certifying Body | Scope |
|---|---|---|
| ISO 9001:2015 | TÜV SÜD | Quality Management System |
| ISO 14001:2015 | Bureau Veritas | Environmental Management |
| ISO 45001:2018 | SGS | Occupational Health & Safety Management System |
| PED 2014/68/EU | Notified Body | European Pressure Equipment |
| NACE MR0175 | NACE International | Sour Service Applications |
| API 6A | American Petroleum Institute | Oil & Gas Equipment |
| IBR Approval | Government of India | Indian Boiler Regulations |
| GOST-R | Rosstandart | Russian Federation |
Upstream production piping, refinery process lines, subsea flowlines, and wellhead connections where chloride corrosion resistance and pressure integrity are critical.
Reactor feed and product lines, heat exchanger piping, and chemical transfer systems handling acids, solvents, and corrosive media.
Water for Injection (WFI) systems, Clean-In-Place (CIP) and Steam-In-Place (SIP) circuits, and sterile transfer lines. WP316L is the standard specification for these applications. Specify electropolished finish (Ra ≤ 0.4 μm) for WFI and sterile systems. FDA 21 CFR compliance should be verified for applicable pharmaceutical process piping.
Sanitary process piping, dairy and brewing transfer lines, and beverage handling systems where hygiene, cleanability, and corrosion resistance are paramount. The smooth internal finish of 316L eliminates biofilm growth in long-service sanitary applications.
Seawater cooling lines, ballast systems, and offshore platform piping where resistance to pitting and crevice corrosion in high-chloride marine environments is essential.
Turbine cooling circuits, feedwater lines, and auxiliary piping systems in conventional and renewable power plants.
Desalination plant piping, reverse osmosis systems, and chemical dosing lines.
Bleaching plant piping, chemical recovery circuits, and liquor handling lines.
| Parameter | WP316 | WP316L |
|---|---|---|
| Carbon Content | Max 0.08% | Max 0.03% |
| Weldability | Good | Excellent |
| Sensitization Risk | Higher (requires PWHT in some cases) | Lower (no PWHT needed) |
| Sensitization Temperature Range | 425–870°C (carbide precipitation risk) | Not susceptible |
| Strength | Slightly higher | Slightly lower |
| Corrosion Resistance | Excellent | Excellent (better in welded condition) |
| Typical Applications | General service | Welded construction without PWHT |
| Cost | Standard | Slightly premium |
| Interchangeability | Can often substitute 316L | Can always substitute 316 |
Expert Recommendation: For welded piping systems without post-weld heat treatment, WP316L is recommended to avoid sensitization and intergranular corrosion. For non-welded applications or where PWHT is performed, WP316 offers slightly better mechanical strength at lower cost. For pharmaceutical WFI and CIP/SIP systems, WP316L is the standard specification because no PWHT is performed after site welding and regulatory requirements preclude intergranular corrosion risk.
Metinox Overseas manufactures both WP316 and WP316L variants to exact specifications, helping you select the optimal grade for your specific application requirements.
When ordering WP316 fittings, always specify the class. The class designation determines the level of non-destructive examination (NDE) performed and the applicable pressure rating.
| Class | Construction Type | NDE Requirement | Pressure Rating |
|---|---|---|---|
| WP-S | Seamless | No NDE required by specification | Per ASME B16.9 |
| WP-W | Welded | Radiography OR ultrasonic on welds | Per ASME B16.9 (lower than WP-S for some configurations) |
| WP-WX | Welded + additional NDE | All welds examined by RT or UT throughout full length | Same as WP-S per ASME B16.9 |
| WP-WU | Welded + UT | Ultrasonic examination throughout entire length of welds | Same as WP-S per ASME B16.9 |
Always include the class designation on your purchase order — it determines the NDE level, documentation requirements, and applicable pressure rating.
| Material | Corrosion Resistance | Temperature Rating | Cost | Weldability | Best Use Case |
|---|---|---|---|---|---|
| WP316 SS | Excellent (chloride resistance) | –196°C to 870°C continuous* | High | Excellent | Chemical, marine, pharmaceutical |
| WP304 SS | Good (general corrosion) | –196°C to 800°C | Medium-High | Excellent | General industrial, indoor |
| Carbon Steel | Poor (requires coating) | –29°C to 427°C† | Low | Good | Non-corrosive services |
| WP321 SS | Good (high temp stability) | –196°C to 900°C | High | Good | High temperature applications |
| Duplex 2205 | Superior (H₂S, chloride) | –50°C to 300°C | Very High | Moderate | Offshore, sour service |
| Alloy 625 | Outstanding (extreme conditions) | –196°C to 1000°C | Premium | Moderate | Severe corrosion, high temp |
| Copper-Nickel | Good (seawater) | –100°C to 300°C | Medium-High | Good | Seawater cooling systems |
*Temperature note for WP316 SS: Continuous service is limited to 870°C (1600°F) per published SSINA guidance and BS EN 10095. For intermittent service, 316 SS can tolerate temperatures up to 870°C; continuous service above 870°C leads to chromium oxide scale spalling. For sustained high-temperature service above 870°C, upgrade to 309S, 310S, or a nickel alloy.
†Carbon Steel advisory: Carbon steel service above 425°C risks graphitisation. Verify suitability per API RP 941 (Nelson Curves).
| Region | Locations |
|---|---|
| India | Mumbai (main warehouse), Delhi, Chennai, Kolkata |
| Middle East | Dubai (partner warehouse), Saudi Arabia, Qatar |
| Asia Pacific | Singapore (partner warehouse), Malaysia, Thailand |
| Europe | Rotterdam (partner warehouse), UK, Germany |
| Americas | Houston (partner warehouse), Canada, Brazil |
ASTM A403 WP316 is an austenitic stainless steel material containing chromium, nickel, and molybdenum. It offers excellent corrosion resistance and is widely used in chemical processing, marine, and food industries.
ASTM A403 specifies the material requirements for stainless steel pipe fittings, while ASME B16.9 defines the dimensions, tolerances, and manufacturing standards for butt weld fittings. Both standards are commonly used together in piping systems.
WP316L refers to wrought pipe fittings made from low-carbon 316 stainless steel. The "L" grade has lower carbon content (max 0.03%), which improves weldability and reduces the risk of carbide precipitation (sensitization) during welding.
ASTM A403 defines four classes: WP-S (seamless, no NDE required), WP-W (welded, radiography or UT on welds), WP-WX (welded, full-length RT or UT throughout all welds), and WP-WU (welded, full-length ultrasonic testing throughout all welds). Always specify the class on your purchase order, as it determines the NDE level, documentation package, and pressure rating applicability.
Metinox Overseas combines over 25 years of manufacturing excellence with rigorous quality control across nine production stages to deliver WP316 fittings that meet the most demanding procurement specifications. Submit your fitting schedule — including size, schedule, quantity, and class (WP-S, W, WX, or WU) — and our technical team will respond with pricing and MTC availability within 4 hours.
Get pricing within 24 hours!