Carbon Steel Flanges Manufacturer and Supplier in India
Amardeep Steel is a reputable manufacturer of carbon steel flanges in India and a supplier of high quality CS flanges to oil and gas, petrochemical, power generating industries, marine and construction industries. We have a history of more than 20 years providing carbon steel pipe flanges with diameters of 1/2 to 48 inch (DN10 to DN5000) in over 80 countries around the world.
Our carbon steel flanges are produced using high grade raw materials like ASTM A105, ASTM A350 LF2 and
ASTM A694 and ASTM A182 and meet international standards such as ANSI/ASME B16.5, B16.47, DIN, BS, JIS and EN. Every flange is tested, dimensionally inspected and certified by a third party prior to shipment to ensure a consistent performance in high pressure, high temperature, and corrosive working conditions.
Do you require weld neck flanges in critical pipeline connections, blind flanges to close the ends of the pipes, socket weld flanges in small-bore systems, Amardeep Steel provides precision-engineered flanges that meet short lead-time requirements, low prices, and full-traceability of the finished material between the mill and the delivery point.
Current stock: 2,000+ line items in ASTM A105N, A350 LF2, and A694 F60/F65. Live stock enquiries available via WhatsApp or email.
Why Choose Amardeep Steel for Carbon Steel Flanges?
Choosing the right carbon steel flanges manufacturer directly impacts project timelines, certification compliance, and total procurement cost. Here is why engineering teams across 80+ countries consistently source CS flanges from Amardeep Steel:
- Direct manufacturer with no middlemen, ensuring better pricing and faster lead times
- Stock availability in ASTM A105N, A350 LF2, A694 F52 to F80 grades
- Size range: 1/2" to 48" across all ANSI pressure classes (150# to 2500#)
- Certifications: EN 10204/3.1, NACE MR0175, NACE MR0103, PED
- Third-party inspection by TUV, Lloyd's, SGS, BV, DNV available
- Export-ready packaging with full MTC documentation
- Supply to 80+ countries including USA, UAE, Saudi Arabia, UK, Germany, Australia
- Approved vendor to major EPC contractors and oil and gas operators including projects in Saudi Aramco, ADNOC, and ONGC supply chains
Need carbon steel flanges for a live project? Send us your line list or size schedule and we will respond with availability, price, and MTC documentation within 24 hours.
Request a QuoteCarbon Steel Flanges Specifications
Amardeep Steel's carbon steel flanges are manufactured to the most widely specified global standards for industrial pipeline systems. The table below summarises the key technical parameters for our standard product range. Custom sizes, special borings, and non-standard pressure classes are available on request.
| Parameter | Details |
|---|---|
| Specifications | ASTM A105 / ASME SA105, A105N |
| Size Range | 1/2" (15 NB) to 48" (1200NB) | DN10 to DN5000 |
| Standards | ANSI/ASME B16.5, B16.47 Series A & B, B16.48, BS4504, BS10, EN-1092, DIN, GOST, JIS |
| Pressure Class (ANSI) | Class 150, 300, 400, 600, 900, 1500, 2500 LBS |
| Pressure Class (DIN) | PN6, PN10, PN16, PN25, PN40, PN64 |
| Pressure Class (JIS) | 5K, 10K, 16K, 20K, 30K, 40K, 63K |
| Face Types | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Lap Joint (LJF), Male-Female |
| Production Technique | Forged, Heat treated, Machined |
| Test Certificates | EN 10204/3.1B, Raw Material Cert, Radiography Test, Third Party Inspection |
For project-specific requirements including dual-certified material, NACE-compliant grades, or third-party witnessed testing, contact our technical sales team with your line specification sheet and we will confirm availability and lead time within 24 hours.
Types of Carbon Steel Flanges We Supply (ANSI / DIN / BS)
We manufacture and stock all standard CS flange connection types as per ANSI/ASME B16.5, B16.47, DIN, and BS specifications. Select the type that matches your pipeline pressure class, bore size, and installation requirement:
Weld Neck Flange (WNRF)
For high-pressure, critical-service applications. The tapered hub distributes stress and enables direct butt-weld connection to the pipe.
Slip-On Flange (SORF)
Easy to install; slips over the pipe and is fillet-welded on both sides. Ideal for low-pressure, non-critical services.
Blind Flange (BLRF)
Used to seal the end of a pipe or pressure vessel. Available in custom bore sizes.
Socket Weld Flange (SWRF)
Best for small-bore, high-pressure piping. Pipe inserts into the socket and is fillet-welded.
Threaded Flange
Screws onto the pipe without welding. Suitable for low-pressure, non-hazardous service.
Lap Joint Flange (LJRF)
Used with a stub end; allows easy bolt-hole alignment and rotation. Common in stainless steel systems with carbon steel backing flanges.
Ring Type Joint Flange (RTJF)
High-pressure and high-temperature applications. Uses a metal ring gasket for a superior seal.
Long Weld Neck Flange
Extended neck provides extra reinforcement. Common in pressure vessels and heat exchangers.
Orifice Flange
Used in pairs for differential pressure flow measurement; includes tapped holes for pressure connections.
Reducing Flange
Connects pipes of different diameters without a reducer fitting.
Forged Carbon Steel Flanges vs Cast Iron Flanges
All carbon steel flanges supplied by Amardeep Steel are forged, not cast. Forging produces a superior grain structure with higher tensile strength, better fatigue resistance, and lower porosity compared to cast iron equivalents. Cast iron flanges are only suitable for low-pressure, non-hazardous gravity flow systems. For any pressurised or high-temperature pipeline application including oil and gas, steam, and petrochemical service, forged carbon steel flanges per ASTM A105 or ASTM A350 are the engineering-correct choice. Casting cannot achieve the mechanical properties required by ANSI/ASME B16.5 for pressure service.
Carbon Steel Flange Grades
Amardeep Steel stocks and supplies all major carbon steel flange grades:
ASTM A105 / A105N Carbon Steel Flanges
The most widely used grade for forged carbon steel flanges. Suitable for ambient and high-temperature service (up to 800°F / 427°C) in pressure piping systems. A105N denotes normalized heat treatment for improved toughness.
ASTM A350 LF2 Low Temperature Carbon Steel Flanges
Designed for cryogenic and sub-zero applications down to -50°F (-45°C). Mandatory Charpy impact testing ensures notch toughness at low temperatures. Used in LNG, refrigeration, and cold-climate pipeline systems.
ASTM A694 Carbon Steel Flanges for High-Pressure Gas Pipelines
High-strength grades for high-pressure oil and gas transmission pipelines. The number (F52, F60, F65, F70, F80) denotes the minimum yield strength in ksi. Ideal for offshore platforms and subsea applications.
ASTM A182 F11 / F22 Alloy Steel Flanges
Chromium-molybdenum alloy grades for high-temperature service in power plants, refineries, and chemical processing. Excellent creep resistance and oxidation resistance.
Chemical Composition of ASTM A105 Carbon Steel Flanges
The chemical composition of ASTM A105 carbon steel flanges must comply with the limits set out in the ASTM standard. All heats supplied by Amardeep Steel are verified against mill test certificates (MTC) traceable to the originating steel mill:
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.35 max |
| Manganese (Mn) | 0.60 to 1.05 |
| Phosphorus (P) | 0.035 max |
| Sulfur (S) | 0.040 max |
| Silicon (Si) | 0.10 to 0.35 |
| Copper (Cu) | 0.40 max |
| Nickel (Ni) | 0.40 max |
| Chromium (Cr) | 0.30 max |
| Molybdenum (Mo) | 0.12 max |
| Vanadium (V) | 0.08 max |
Mechanical Properties of Carbon Steel Pipe Flanges
Minimum mechanical property requirements for ASTM A105 forgings as specified in ASTM A105/A105M:
| Mechanical Property | Requirement |
|---|---|
| Tensile Strength, min | 70,000 psi [485 MPa] |
| Yield Strength, min | 36,000 psi [250 MPa] |
| Elongation, min | 30% |
| Reduction of Area, min | 30% |
| Hardness, max | 187 HB |
Pressure Ratings (ASTM A105, psi)
ANSI/ASME B16.5 pressure-temperature ratings for ASTM A105 carbon steel flanges (psi). These values apply to flanges in the base material condition; de-rate if operating above 800°F or if corrosion allowances reduce the minimum wall thickness:
| Temp (°F) | 150# | 300# | 600# | 900# | 1500# | 2500# |
|---|---|---|---|---|---|---|
| < 100 | 285 | 740 | 1480 | 2220 | 3705 | 6170 |
| 200 | 260 | 680 | 1360 | 2035 | 3395 | 5655 |
| 400 | 200 | 635 | 1265 | 1900 | 3170 | 5280 |
| 600 | 140 | 570 | 1135 | 1705 | 2840 | 4730 |
| 800 | 80 | 410 | 825 | 1235 | 2055 | 3430 |
| 1000 | 20 | 85 | 170 | 255 | 430 | 715 |
Carbon Steel Flange Weight Reference (ANSI B16.5, ASTM A105)
Approximate weights in pounds for weld neck (WN), slip-on (SO), and blind (BL) carbon steel flanges per ANSI B16.5 in Class 150 and Class 300. Weight data is essential for shipping cost calculation and structural load analysis. Contact us for exact certified weights from our product records:
| NPS | WN 150# (lbs) | WN 300# (lbs) | SO 150# (lbs) | SO 300# (lbs) | BL 150# (lbs) | BL 300# (lbs) |
|---|---|---|---|---|---|---|
| 1" | 3 | 4 | 2 | 3 | 2 | 3 |
| 1-1/2" | 5 | 7 | 3 | 5 | 3 | 5 |
| 2" | 7 | 10 | 5 | 7 | 5 | 8 |
| 3" | 13 | 19 | 9 | 13 | 10 | 14 |
| 4" | 20 | 30 | 14 | 20 | 15 | 23 |
| 6" | 40 | 60 | 27 | 40 | 30 | 45 |
| 8" | 65 | 97 | 44 | 65 | 50 | 74 |
| 10" | 100 | 148 | 68 | 100 | 77 | 113 |
| 12" | 145 | 215 | 98 | 145 | 112 | 163 |
| 16" | 230 | 350 | 155 | 230 | 180 | 265 |
| 20" | 365 | 550 | 245 | 365 | 285 | 420 |
| 24" | 520 | 780 | 348 | 520 | 405 | 595 |
Industries and Applications for Carbon Steel Pipe Flanges
- Oil and Gas Pipelines: Connecting wellheads, flow lines, and transmission pipelines on onshore and offshore installations
- Petrochemical Plants: Flanged connections for process vessels, heat exchangers, reactors, and distillation columns
- Power Generation: Steam lines, boiler connections, and turbine inlet/outlet piping in thermal and nuclear power plants
- Water and Wastewater Treatment: Large-diameter flanges for pump connections, valve isolation, and pipeline manifolds
- Shipbuilding and Marine: Ballast systems, fuel lines, and bilge piping in vessels operating in demanding marine environments
- Chemical Processing: Flanged joints in acid, alkali, and solvent service pipelines where carbon steel is compatible
- Construction and Infrastructure: Industrial water supply and fire suppression piping systems
- HVAC and Utilities: Carbon steel flanges for chilled water, steam distribution, and air handling piping in commercial and industrial HVAC systems
- Fertiliser and Pharmaceutical: Flanged connections for ammonia, urea, and solvent transfer pipelines in fertiliser plants and pharmaceutical processing facilities
Carbon Steel Flange Surface Coatings and Finishing Options
Standard and custom surface treatment options are available on all CS flanges:
- Anti-rust oil coating: Standard dispatch protection for storage and transit
- Yellow passivation: Phosphate-based treatment for indoor storage environments
- Electric zinc coating (white or yellow): For moderate corrosion environments
- Hot-dip galvanizing: For outdoor, marine, and high-humidity installations
- Epoxy or polyurethane coating: Custom specification for offshore, subsea, and aggressive-service environments
Standards and Codes We Comply With
Every carbon steel flange supplied by Amardeep Steel is designed and tested to one or more of the following internationally recognised standards. Compliance certificates are included in the shipment documentation:
- ANSI/ASME B16.5: Pipe Flanges and Flanged Fittings (NPS 1/2" to 24")
- ANSI/ASME B16.47: Large Diameter Steel Flanges (NPS 26" to 60"), Series A and B
- ANSI/ASME B16.48: Line Blanks
- MSS SP-44: Steel Pipeline Flanges
- API 605: Large Diameter Carbon Steel Flanges
- DIN 2527 / 2566 / 2573 / 2576 / 2631 to 2638
- BS 4504 / BS 10 / BS 1560
- EN 1092-1 / JIS B2220 / GOST 12820
- AWWA C207: Steel Pipe Flanges for Waterworks Service (where applicable)
Frequently Asked Questions about Carbon Steel Flanges
What is the most common grade for carbon steel flanges?
ASTM A105 is the industry standard for forged carbon steel flanges used in ambient and elevated-temperature service. For low-temperature applications, ASTM A350 LF2 is specified. For high-pressure gas transmission, ASTM A694 grades (F52 to F80) are used.
What is the difference between ASTM A105 and A350 LF2 carbon steel flanges?
ASTM A105 is the standard grade for ambient and elevated-temperature service (up to 800°F / 427°C). ASTM A350 LF2 is a low-temperature grade, impact-tested down to -50°F (-45°C), and is mandatory in cryogenic, LNG, and cold-climate pipeline systems where A105 would become brittle.
What sizes and pressure classes are available?
Amardeep Steel supplies carbon steel flanges from 1/2" to 48" NPS (DN10 to DN5000) in all ANSI pressure classes from 150# to 2500#, and DIN classes from PN6 to PN100. Custom sizes and special borings are available on request.
Do you provide third-party inspection and certifications?
Yes. We provide full material test certificates (MTC) as per EN 10204/3.1 and 3.2, NACE MR0175, NACE MR0103 compliance, and third-party inspection by agencies including TUV, Lloyd's Register, SGS, Bureau Veritas, and DNV-GL.
Do you supply carbon steel flanges with material test certificates (MTC)?
Yes. All Amardeep Steel carbon steel flanges are supplied with EN 10204/3.1 mill test certificates as standard. For critical applications requiring witnessed inspection or dual certification to EN 10204/3.2, we coordinate with accredited third-party agencies including TUV, SGS, Lloyd's Register, Bureau Veritas, and DNV-GL.
What is your minimum order quantity?
There is no strict MOQ for standard sizes. We supply from single pieces for urgent requirements to bulk orders for project procurement. Please contact our sales team with your requirements for a competitive quote.
How quickly can you supply carbon steel flanges?
Standard ASTM A105 flanges in common sizes are available from stock and can be dispatched within 2 to 5 business days. Non-standard sizes, special grades, or large-volume orders typically have a lead time of 2 to 4 weeks depending on specifications.
Can you supply carbon steel flanges with special coatings?
Yes. We offer anti-rust oil coating (standard), yellow passivation, electric zinc coating (white or yellow), hot-dip galvanizing, and custom epoxy or polyurethane coatings as per project requirements.
Related Products
- Carbon Steel Pipes & Tubes
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- Carbon Steel Bars, Rods & Wires
- Carbon Steel Forged Fittings
- Carbon Steel Flanges
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- Carbon Steel Fasteners
Source carbon steel pipe flanges from a direct manufacturer with no middlemen, better pricing, and faster dispatch. Amardeep Steel ships to 80+ countries with full EN 10204/3.1 documentation, export-ready packaging, and support from our technical team. Contact us today for a quote or to request a free sample MTC.
Contact Us TodayOur Products
◆Carbon Steel Plates, Sheets & Coils
◆Carbon Steel Bars, Rods & Wires
◆Carbon Steel Buttweld Fittings