DIN Flanges
DIN Flange: Specifications | Materials | Dimensions | Weight Chart | Tolerances | FAQ
DIN Flanges Manufacturer and Supplier in USA, Germany, UAE, India, and South Korea offering high-quality Weld Neck, Slip-On, Blind, and Lap Joint flanges in Carbon, Alloy, and Stainless Steel as per DIN 2573, DIN 2576, DIN 2631, DIN 2633, and DIN 2635 standards for industrial, oil, gas, petrochemical, chemical, and power plant piping systems.
Best Export Prices: sales@midlandforgefittings.com
Midland Forge Fittings is a leading manufacturer and supplier of high-quality industrial piping components, including DIN Flange, dedicated to providing precision-engineered solutions for global markets. Equipped with state-of-the-art forging facilities and stringent quality control protocols, we ensure that every product meets international standards and delivers exceptional performance, reliability, and durability.
Our company operates on a robust work structure that integrates advanced manufacturing processes, skilled workforce, and modern testing laboratories. From material selection to final inspection, Midland Forge Fittings maintains stringent procedures to guarantee consistent product quality and dimensional accuracy for complex industrial applications.
We offers a comprehensive range of DIN Flanges, manufactured from carbon steel, alloy steel, and stainless steel to meet stringent international standards. Our flanges are available in Weld Neck, Slip-On, Blind, and Lap Joint types, adhering to major DIN standards such as DIN 2573, DIN 2576, DIN 2631, DIN 2633, and DIN 2635. Each flange is precision-forged and machined to ensure accurate bolt hole alignment, face flatness, and dimensional tolerances critical for high-pressure and high-temperature piping systems.
Engineered for reliability in industrial, petrochemical, oil & gas, and chemical applications, our DIN Blind Flanges provide superior corrosion resistance, mechanical strength, and leak-proof performance. Compliance with DIN standards ensures compatibility with global piping networks, while our rigorous testing—including ultrasonic, radiographic, and dimensional inspection—guarantees quality and durability for demanding environments and large diameter pipelines.
With a global footprint spanning the USA, Europe, Middle East, and Asia, we specialize in supplying DIN WNRF Flange for diverse industries including oil & gas, petrochemical, chemical, power generation, and offshore projects. Our focus on innovation, timely delivery, and customer support positions us as a trusted partner in critical piping solutions.
DIN Flange - Specifications
DIN 2573 Weld Neck Flange - Materials, Grades & Standards
| Material Type | Grades / Standards | Notes / Applications |
|---|---|---|
| Carbon Steel | DIN 1.0038 (C22), DIN 1.0619 (C35), ASTM A105, A350 LF2 |
Standard industrial and medium-pressure piping systems |
| Alloy Steel | DIN 1.7335 (16Mo3), DIN 1.7380 (15CrMo), ASTM A182 F1, F5, F9, F11, F22 |
High-temperature, high-pressure, and steam applications |
| Stainless Steel | DIN 1.4301 (X5CrNi18-10), DIN 1.4401 (X5CrNiMo17-12-2), ASTM A182 F304/F304L, F316/F316L, F321, F347 |
Corrosion-resistant, used in chemical, petrochemical, and offshore applications |
| Duplex / Super Duplex | UNS S31803, UNS S32750 | Excellent corrosion resistance & mechanical strength for harsh environments |
| Nickel Alloys | Inconel, Monel, Hastelloy | Extreme temperature and highly corrosive environments |
| Forged Steel | DIN 2573 / 2576 / 2631 Forgings | Used for high-pressure piping and heavy-duty industrial applications |
Precision-Forged DIN Flanges – Dimensions
Midland Forge Fittings is a leading DIN Flanges manufacturer and supplier, offering Weld Neck, Slip-On, Blind, Lap Joint, and Threaded flanges in Carbon Steel, Alloy Steel, and Stainless Steel. Precision-forged to DIN standards including DIN 2573, 2576, 2631, 2633, 2635, and 2848, our flanges ensure accurate dimensions, high strength, and corrosion resistance for industrial, oil & gas, petrochemical, and power plant piping systems.
| Flange Type | Nominal Size (DN / NPS) |
Outside Diameter (OD, mm) |
Bolt Circle Diameter (BCD, mm) |
Number of Bolts |
Bolt Diameter (mm) |
Flange Thickness (mm) |
Material / Standard |
Face Type |
|---|---|---|---|---|---|---|---|---|
| Weld Neck (DIN 2573) | DN 15 – DN 600 (½” – 24”) | 95 – 600 | 65 – 565 | 4 – 20 | 14 – 26 | 12 – 75 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 | RF / FF |
| Weld Neck (DIN 2576) | DN 15 – DN 600 (½” – 24”) | 100 – 610 | 70 – 570 | 4 – 20 | 14 – 26 | 15 – 80 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2576 | RF / FF |
| Slip-On (DIN 2631) | DN 15 – DN 400 (½” – 16”) | 95 – 400 | 65 – 370 | 4 – 16 | 14 – 24 | 10 – 60 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2631 | RF / FF |
| Blind (DIN 2633) | DN 15 – DN 600 (½” – 24”) | 95 – 600 | 65 – 565 | 4 – 20 | 14 – 26 | 12 – 75 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2633 | RF / FF |
| Lap Joint (DIN 2526) | DN 15 – DN 300 (½” – 12”) | 95 – 320 | 65 – 280 | 4 – 12 | 14 – 22 | 10 – 40 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2526 | RF / FF |
| Threaded / Screwed (DIN 2527) | DN 15 – DN 300 (½” – 12”) | 95 – 320 | 65 – 280 | 4 – 12 | 14 – 22 | 10 – 40 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2527 | FF |
| Stainless / Duplex (DIN 2636, 2637) | DN 15 – DN 600 (½” – 24”) | 95 – 600 | 65 – 565 | 4 – 20 | 14 – 26 | 12 – 75 | Stainless Steel, Duplex / Super Duplex / DIN 2636, 2637 | RF / FF |
| Large / Special Flanges (DIN 2848, 3352) | DN 700 – DN 2000+ (28” – 80”+) | 700 – 2500+ | 670 – 2450+ | 20 – 120 | 26 – 70 | 80 – 300+ | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2848, 3352 | RF / FF / RTJ |
DIN 2631 Slip-On Flange, DIN 2633 Blind Flange - Weight Chart
| Flange Type | Nominal Size (DN / NPS) |
Flange Thickness (mm) |
Approx. Weight (kg) |
Material / Standard |
|---|---|---|---|---|
| Weld Neck (DIN 2573) |
DN 15 – DN 50 (½” – 2”) | 12 – 20 | 3 – 8 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 |
| Weld Neck (DIN 2573) |
DN 65 – DN 100 (2½” – 4”) | 22 – 30 | 12 – 25 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 |
| Weld Neck (DIN 2573) |
DN 125 – DN 200 (5” – 8”) | 25 – 40 | 30 – 70 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 |
| Weld Neck (DIN 2573) |
DN 250 – DN 400 (10” – 16”) | 40 – 60 | 80 – 200 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 |
| Weld Neck (DIN 2573) |
DN 450 – DN 600 (18” – 24”) | 60 – 75 | 220 – 400 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2573 |
| Slip-On (DIN 2631) |
DN 15 – DN 100 (½” – 4”) | 10 – 30 | 2 – 20 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2631 |
| Slip-On (DIN 2631) |
DN 125 – DN 400 (5” – 16”) | 25 – 60 | 25 – 150 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2631 |
| Blind (DIN 2633) |
DN 15 – DN 100 (½” – 4”) | 12 – 30 | 3 – 22 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2633 |
| Blind (DIN 2633) |
DN 125 – DN 400 (5” – 16”) | 25 – 60 | 28 – 180 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2633 |
| Lap Joint (DIN 2526) |
DN 15 – DN 100 (½” – 4”) | 10 – 25 | 2 – 15 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2526 |
| Lap Joint (DIN 2526) |
DN 125 – DN 300 (5” – 12”) | 25 – 50 | 18 – 100 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2526 |
| Threaded / Screwed (DIN 2527) |
DN 15 – DN 100 (½” – 4”) | 10 – 25 | 2 – 15 | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2527 |
| Stainless / Duplex (DIN 2636, 2637) |
DN 15 – DN 600 (½” – 24”) | 12 – 75 | 5 – 400 | Stainless Steel, Duplex / Super Duplex / DIN 2636, 2637 |
| Large / Special Flanges (DIN 2848, 3352) |
DN 700 – DN 2000+ (28” – 80”+) | 80 – 300+ | 500 – 8000+ | Carbon Steel, Alloy Steel, Stainless Steel / DIN 2848, 3352 |
DIN 2573, DIN 2576 Flanges - Tolerances
| Flange Type |
Nominal Size (DN / NPS) |
OD Tolerance |
Bolt Circle Diameter (BCD) Tolerance |
Bolt Hole Diameter Tolerance |
Flange Thickness Tolerance |
Bore / Hub Tolerance |
Face Flatness |
Out-of- Roundness |
|---|---|---|---|---|---|---|---|---|
| Weld Neck (DIN 2573 / 2576) |
DN 15 – DN 600 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | RF / FF: ≤0.8 mm | ≤1.5% of OD |
| Slip-On (DIN 2631) |
DN 15 – DN 400 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | RF / FF: ≤0.8 mm | ≤1.5% of OD |
| Blind (DIN 2633) |
DN 15 – DN 600 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | RF / FF: ≤0.8 mm | ≤1.5% of OD |
| Lap Joint (DIN 2526) |
DN 15 – DN 300 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | RF / FF: ≤0.8 mm | ≤1.5% of OD |
| Threaded / Screwed (DIN 2527) |
DN 15 – DN 300 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | FF: ≤0.5 mm | ≤1.5% of OD |
| Stainless / Duplex (DIN 2636 / 2637) |
DN 15 – DN 600 | ±1.5% of OD | ±1% of BCD | ±0.5 mm | ±5% nominal thickness |
H11 / h11 | RF / FF: ≤0.8 mm | ≤1.5% of OD |
| Large / Special (DIN 2848 / 3352) |
DN 700 – DN 2000+ | ±1.5 – 2% OD | ±1 – 1.5% BCD | ±0.5 – 1 mm | ±5% – 7% thickness |
H11 / h11 | RF / FF / RTJ: ≤1.0 mm | ≤2% of OD |
What are the common types of DIN Flanges and their applications?
DIN flanges are classified by their connection type and application requirements:
Weld Neck Flanges (DIN 2573 / 2576):
- Designed with a long tapered hub, distributing stress evenly to the pipe.
- Suitable for high-pressure and high-temperature applications, including oil & gas pipelines and chemical plants.
Slip-On Flanges (DIN 2631):
- Pipe slides into the flange bore and is welded both inside and outside.
- Used in medium-pressure systems where alignment ease is critical.
Blind Flanges (DIN 2633):
- Used to terminate or close the end of a piping system.
- Withstands high pressure and allows for testing of pressure systems.
Lap Joint Flanges (DIN 2526):
- Works with stub ends for removable connections.
- Ideal for low-pressure applications where frequent disassembly is needed.
Threaded / Screwed Flanges (DIN 2527):
- Screw-on connection without welding; convenient for small-diameter or temporary pipelines.
- Suitable for low-pressure and low-temperature systems.
Stainless / Duplex Flanges (DIN 2636 / 2637):
- High corrosion resistance for chemical, offshore, and subsea pipelines.
- Can handle high pressure, high temperature, and harsh environments.
Large / Special Flanges (DIN 2848 / 3352):
- Custom flanges for large diameter pipelines in power plants, petrochemical, and offshore industries.
What are DIN Flanges and why are they used?
DIN Flanges are mechanical components designed to connect pipes, valves, pumps, and other equipment in industrial piping systems. They are manufactured according to Deutsches Institut für Normung (DIN) standards, ensuring dimensional accuracy and compatibility. Their use is critical due to:
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Standardization and Interchangeability: DIN standards provide precise dimensions, bolt patterns, and face designs, allowing flanges from different manufacturers to be interchangeable without rework.
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Reliable Sealing: Flanges are machined with specific face types like Raised Face (RF), Flat Face (FF), and Ring Type Joint (RTJ), ensuring optimal gasket sealing under pressure.
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Mechanical Strength: Designed to handle internal pressure, temperature variations, and mechanical stresses, preventing failure or leakage in critical systems.
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Material Versatility: DIN flanges are available in Carbon Steel, Alloy Steel, Stainless Steel, and Duplex/Super Duplex, allowing them to withstand various environments including corrosive, high-temperature, or offshore conditions.
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Ease of Installation and Maintenance: Flanges allow for easy assembly, disassembly, inspection, and maintenance of piping systems.
How to select the right DIN Flange for an application?
Proper flange selection is based on application, pressure, temperature, material, and standards:
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Flange Type: Choose Weld Neck, Slip-On, Blind, Lap Joint, or Threaded depending on pressure, mechanical requirements, and installation.
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Material: Select Carbon, Alloy, Stainless, Duplex, or Nickel alloys based on corrosion, temperature, and mechanical load.
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Nominal Size (DN / NPS): Match flange to the pipe diameter.
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Pressure Class (PN Rating): PN10, PN16, PN25, PN40, PN63 depending on system pressure.
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Face Type: RF, FF, or RTJ depending on gasket type and sealing requirements.
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Standards Compliance: Ensure flange adheres to DIN 2573, 2576, 2631, 2633, 2848, or other DIN standards for industrial and critical applications.