AstroForge Fitting Industries delivers precision-engineered fasteners built for strength, reliability, and extreme industrial environments.

Nickel Flanges

 

SS 304 / 304L Forged Flanges Manufacturer in India

AstroForge Fitting Industries is a renowned manufacturer and exporter of ASTM A182 SS 304 / 304L Forged Flanges in India.
We offer a comprehensive range of Stainless Steel 304/304L Flanges, including Weld Neck, Slip On, Blind, Socket Weld, Threaded, Lap Joint, and Ring Type Joint (RTJ) Flanges, designed for strength, durability, and excellent corrosion resistance.

These ASTM A182 Grade 304 / 304L Flanges are manufactured using high-grade raw materials under strict quality control and are widely used in petrochemical, power generation, marine, and food processing industries.

Manufacturing Standards

All SS 304 / 304L Flanges are manufactured as per:

  • ASTM A182 / ASME SA182 (F304 / F304L)

  • ASME B16.5, B16.47, DIN, BS, and EN standards

  • ISO 9001:2015 certified production and testing

Available Types of Stainless Steel 304 / 304L Flanges

  • Slip On Flange (SORF)

  • Weld Neck Flange (WNRF)

  • Blind Flange (BLRF)

  • Socket Weld Flange (SWRF)

  • Lap Joint Flange (LJFF)

  • Threaded Flange (THRF)

  • Ring Type Joint Flange (RTJ)

  • Reducing & Orifice Flanges

Size Range

  • ½” NB to 48” NB

  • Pressure Ratings: Class 150, 300, 600, 900, 1500 & 2500

  • Facing Type: RF / FF / RTJ

  • Connection Type: Welded / Threaded / Screwed

Description

Flanges are vital pipe components used for connecting pipes, valves, pumps, and other equipment to form a complete piping system.
SS 304 / 304L Forged Flanges are manufactured through the forging process, ensuring superior strength, dimensional accuracy, and resistance to corrosion and pressure.

Our Stainless Steel 304 / 304L Flanges are available in various face types — Raised Face (RF), Flat Face (FF), and Ring Type Joint (RTJ) — suitable for different industrial applications.

SS 304 vs SS 304L Flanges

  • SS 304 contains higher carbon (≤ 0.08%) offering high strength and hardness.

  • SS 304L (Low Carbon) contains ≤ 0.035% carbon, preventing carbide precipitation and ensuring better weldability.

Dimensional Range of ASTM A182 SS 304 / 304L Flanges

TypeSize (NB)Pressure RatingFace TypeStandards
Weld Neck (WNRF)½” – 48”150# – 2500#RF / RTJASME B16.5 / B16.47
Slip On (SORF)½” – 48”150# – 2500#RF / FFASME B16.5
Blind (BLRF)½” – 48”150# – 2500#RF / RTJASME B16.5
Socket Weld (SWRF)½” – 4”150# – 2500#RFASME B16.11
Threaded (THRF)½” – 4”150# – 2500#FF / RFASME B16.11
Lap Joint (LJFF)½” – 24”150# – 900#FFASME B16.5

Chemical Composition of Stainless Steel 304 / 304L Flanges

Element304 (%)304L (%)
Carbon (C)≤ 0.08≤ 0.035
Manganese (Mn)≤ 2.00≤ 2.00
Silicon (Si)≤ 1.00≤ 1.00
Phosphorus (P)≤ 0.045≤ 0.045
Sulfur (S)≤ 0.030≤ 0.030
Chromium (Cr)18.00 – 20.0018.00 – 20.00
Nickel (Ni)8.00 – 11.008.00 – 12.00
Nitrogen (N)≤ 0.10≤ 0.10
Iron (Fe)BalanceBalance

Mechanical & Physical Properties of SS 304 / 304L Flanges

Property304304L
Tensile Strength (MPa)515 min485 min
Yield Strength (MPa)205 min170 min
Elongation (%)40 min40 min
Hardness (Brinell)≤ 201≤ 201
Density8.0 g/cm³8.0 g/cm³

Heat Resistance

  • SS 304 flanges resist oxidation up to 870°C in intermittent and 925°C in continuous service.

  • SS 304L provides better resistance to intergranular corrosion after welding or stress-relief treatment.

Solution Treatment:
Annealing at 1050°C followed by water quenching is recommended for restoring corrosion resistance after fabrication.

Weldability

SS 304 and 304L flanges can be welded by all standard methods, including TIG, MIG, and Arc welding, with or without filler metal.
Post-weld annealing is not necessary for SS 304L due to its low carbon content.

Applications of SS 304 / 304L Forged Flanges

  • Oil & Gas Pipeline Systems

  • Petrochemical and Refinery Equipment

  • Power Generation & Heat Exchangers

  • Marine & Offshore Structures

  • Food & Beverage Processing Units

  • Water Treatment & Sewage Systems

  • Pulp & Paper Industry

Quality Assurance & Testing

Each Stainless Steel 304 / 304L Flange is subjected to:

  • Visual & Dimensional Inspection

  • Ultrasonic & Radiographic Testing

  • Hydrostatic Pressure Testing

  • PMI (Positive Material Identification)

  • Mechanical & Chemical Analysis

  • Intergranular Corrosion (IGC) Test

  • Third-Party Inspection Reports (TPI)

All flanges are supplied with EN 10204/3.1B Mill Test Certificates, ensuring traceability and compliance with international standards.

Packaging & Marking

  • Flanges are protected with plastic end caps

  • Wrapped in bubble wrap or HDPE sheets

  • Packed in fumigated wooden crates or pallets

  • Each flange is marked with Grade, Size, Heat No., and Country of Origin

Why Choose AstroForge Fitting Industries

  • ISO 9001:2015 Certified Company

  • State-of-the-art Manufacturing Facilities

  • Custom Flanges per Client Drawings & Specifications

  • Competitive Pricing with Timely Delivery

  • Exporter to 40+ Countries Worldwide

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FAQs - SS 316/316L Forged Flanges

SS 316/316L Forged Flanges are high-quality stainless steel flanges made from grade 316 or 316L through the forging process. They offer excellent corrosion resistance, high tensile strength, and durability, suitable for critical piping applications.

The main difference lies in carbon content: 316L has lower carbon, making it ideal for welding and reducing carbide precipitation. Both offer superior corrosion resistance, but 316L is preferred in high-temperature and corrosive environments.

ommon types include:

  • Weld Neck Flanges (WN)

  • Slip-On Flanges (SO)

  • Socket Weld Flanges (SW)

  • Blind Flanges (BL)

  • Threaded Flanges (TH)

  • Lap Joint Flanges (LJ)

They are manufactured according to standards like ASTM A182, ASME B16.5, ASME B16.47, and EN 1092, ensuring high quality and international compliance.

Used extensively in chemical processing, oil & gas, petrochemical, marine, pharmaceutical, and food industries due to their excellent resistance to chloride corrosion and high-temperature environments.

Forged flanges offer superior mechanical strength, uniformity, and resistance to high pressure and temperature compared to cast or welded flanges, making them suitable for critical industrial pipelines.

SS 316/316L Forged Flanges are available in sizes ranging from ½ inch to 48 inches and in pressure classes 150#, 300#, 600#, 900#, 1500#, and 2500#, with custom sizes on request.

The presence of molybdenum in the alloy enhances resistance to pitting and crevice corrosion, especially in chloride-rich environments.

Yes, both 316 and 316L flanges are suitable for welding. 316L is particularly ideal due to its low carbon content, which minimizes the risk of carbide precipitation and weld decay.

Regular cleaning with mild detergents, avoiding harsh chemicals, and periodic inspection for corrosion or wear can prolong the service life. Passivation is recommended for critical applications.