ASTM A709 Steel Flange, grade 50 and 50W

1,We Manufacturing processes are primarily classified into four types: 1:Forging, 2:Casting, 3:Cutting, 4:Rolling. 2,We can manufacture in accordance with these standards. Standards: GB Series (Chinese Standards), JB Series (Machinery Standards), HG Series (Chemical Industry Standards), ASME B16.5 (American Standards), BS4504 (British Standards), DIN (German Standards), and JIS (Japanese Standards). Internationally, there are two primary systems of pipe flange standards: the European system, represented by the German DIN standards (including those of the former Soviet Union), and the American system, represented by the US ANSI pipe flange standards. Other common standards include: the Chinese Ministry of Machinery Industry standards (JB series), the Ministry of Chemical Industry standards (HG series), the Chinese National Standard *GB/T 9112–9124-2010 Steel Pipe Flanges*, as well as US standards (ASME B16.5), British standards (BS4504), German standards (DIN), Japanese standards (JIS), and marine standards (CBM), among others. The nominal pressure ratings for the PN series are designated by "PN" and comprise the following nine levels: PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. The nominal pressure ratings for the Class series are designated by "Class" and comprise the following six levels: Class150, Class300, Class600, Class900, Class1500, and Class2500. Flange Classification 1. **According to Chemical Industry Standards:** Flanges are classified as follows: Plate Flat Welding Flange (PL), Necked Flat Welding Flange (SO), Necked Butt Welding Flange (WN), Integral Flange (IF), Socket Welding Flange (SW), Threaded Flange (Th), Butt Welding Ring Loose Flange (PJ/SE), Blind Flange (BL), Flat Welding Ring Loose Flange (PJ/PJ), and Lined Blind Flange (BL(s)). 2. **According to Petrochemical (SH) Industry Standards:** Flanges are classified as follows: Threaded Flange (PL), Butt Welding Flange (WN), Flat Welding Flange (SO), Socket Welding Flange (SW), Loose Flange (LJ), and Blind Flange (no specific designation). 3. **According to Machinery (JB) Industry Standards:** Flanges are classified as follows: Integral Flange, Butt Welding Flange, Plate Flat Welding Flange, Butt Welding Ring Plate Loose Flange, Flat Welding Ring Plate Loose Flange, Lap Joint Ring Plate Loose Flange, and Blind Flange. 4. **According to Connection Method/Type:** Flanges are classified as follows: Plate Flat Welding Flange, Necked Flat Welding Flange, Necked Butt Welding Flange, Socket Welding Flange, Threaded Flange, Blind Flange, Necked Butt Welding Ring Loose Flange, Flat Welding Ring Loose Flange, Ring-Type Joint (RTJ) Flange and Blind Flange, Large-Diameter Plate Flange, Large-Diameter High-Neck Flange, Figure-8 Blind Plate, Butt Welding Ring Loose Flange, etc. 5. **According to the Component Being Connected:** Flanges can be classified into Vessel Flanges and Pipe Flanges. 6. **According to Structural Type:** Flanges include Integral Flanges, Threaded Flanges, Flat Welding Flanges, Butt Welding Flanges, Lap Joint (Loose/Swivel) Flanges, and Blind Flanges. A flange—also referred to as a flange plate or rim—is a component used to connect shafts to one another, or, more commonly, to join the ends of pipes. Flanges are also utilized at the inlet and outlet ports of equipment to facilitate connections between two devices—for instance, the flange on a speed reducer. A "flange connection" or "flanged joint" refers to a detachable joint assembly comprising three interconnected elements—a flange, a gasket, and bolts—that together form a sealed structural unit. In the context of piping systems, a "pipe flange" specifically denotes a flange used for plumbing within the installation; when applied to equipment, it refers to the inlet or outlet flange of that specific device. Flanges feature a series of holes through which bolts are inserted to securely fasten the two flanges together, while a gasket placed between the flanges ensures a leak-proof seal. Flanges are broadly categorized into three types: threaded (screw-in) flanges, welded flanges, and clamp-type flanges. Flanges are invariably used in pairs; threaded flanges are suitable for low-pressure piping applications, whereas welded flanges are required for systems operating at pressures exceeding 4 kilograms per square centimeter. A sealing gasket is inserted between the two flange plates, which are then firmly secured using bolts. The thickness of a flange—as well as the specifications of the bolts used to fasten it—vary depending on the specific pressure rating required for the application. When connecting equipment such as water pumps or valves to piping systems, the corresponding connection points on these devices are often manufactured in the shape of a matching flange; this method of attachment is also referred to as a "flange connection." Generally, any connecting component that utilizes bolts to join and seal the perimeters of two flat surfaces—such as the joints in ventilation ducts—is termed a "flange"; such components may collectively be classified as "flange-type parts." However, since such a connection often constitutes merely a *portion* of a larger device—for instance, the interface between a flange and a water pump—it would be inappropriate to classify the entire water pump itself as a "flange-type part." Conversely, smaller components—such as valves—that feature such flanged interfaces may indeed be appropriately categorized as "flange-type parts." -:- For detailed product information, please contact sales. -: ASTM A709 Steel Flange, grade 50 and 50W, ≤ 100 mm Product Information -:- For detailed product information, please contact sales. -: ASTM A709 Steel Flange, grade 50 and 50W, ≤ 100 mm Synonyms -:- For detailed product information, please contact sales. -:

ASTM A709 Steel, grade 50 and 50W, ≤ 100 mm Product Information -:- For detailed product information, please contact sales. -: ## **Product Specification: ASTM A709 High-Performance Structural Steel (Grades 50 & 50W)** ### **Product Designation** * **Standard:** ASTM A709 / A709M * **Grades Covered:** **Grade 50 (A709-50)** & **Grade 50W (A709-50W)** * **Condition:** As-rolled, thermo-mechanically controlled processed (TMCP), or quenched & tempered (depending on thickness/product form). * **Product Form:** Shapes, plates, and bars. * **Thickness/Size Scope:** **≤ 100 mm (4 inches)** – For plates, this is typically the as-rolled or TMCP condition. ### **Overview** ASTM A709 is the comprehensive standard specification for **carbon and high-strength low-alloy (HSLA) structural steel shapes, plates, and bars** for use in **bridges and other structural applications**. It consolidates several traditional ASTM specs (like A36, A572, A588) into a single bridge-focused standard with additional toughness requirements. * **Grade 50:** The most common high-strength steel for bridges, offering a minimum yield strength of 50 ksi (345 MPa). * **Grade 50W:** The "W" denotes "Weathering." This grade is chemically designed to form a stable, adherent rust patina (oxide layer) when exposed to the atmosphere, which inhibits further corrosion. This eliminates the need for protective painting in many environments, offering significant lifecycle cost savings. ### **1. Chemical Composition (Maximum % by Weight, for Plates ≤ 100mm)** Composition varies by production process (as-rolled vs. TMCP) and grade. The following are typical maximums or ranges. | Element | Grade 50 (Typical) | Grade 50W (Typical) | Role & Effect | | :--- | :--- | :--- | :--- | | **Carbon (C)** | 0.23 max | 0.19 max | Provides strength; lower in 50W for improved weldability and toughness. | | **Manganese (Mn)** | 1.35 max | 0.80 - 1.35 | Increases strength and hardenability; crucial for achieving yield strength. | | **Phosphorus (P)** | 0.04 max | 0.04 max | Impurity; controlled low. In 50W, it aids weathering resistance. | | **Sulfur (S)** | 0.05 max | 0.05 max | Impurity; controlled low for improved ductility and through-thickness properties. | | **Silicon (Si)** | 0.40 max | 0.30 - 0.65 | Deoxidizer; in 50W, it is essential for promoting the protective weathering patina. | | **Copper (Cu)** | 0.20 min (if specified) | **0.20 - 0.40** | **Key for 50W.** Critical element for atmospheric corrosion resistance. Often present in Grade 50 as well. | | **Chromium (Cr)** | - | 0.40 - 0.70 | Enhances weathering resistance in Grade 50W. | | **Nickel (Ni)** | - | 0.25 - 0.50 | Enhances weathering resistance and low-temperature toughness in Grade 50W. | | **Vanadium (V)** | 0.01 - 0.15* | 0.02 - 0.10* | Microalloying element; provides grain refinement and precipitation strengthening (common in TMCP grades). | | **Columbium (Cb/Nb)**| 0.005 - 0.05* | 0.005 - 0.05* | Microalloying element; powerful grain refiner and strengthener (common in TMCP grades). | *Note: *Microalloying elements (V, Cb) are used individually or in combination in modern TMCP steels to achieve mechanical properties with lower carbon content, enhancing weldability.* ### **2. Physical & Mechanical Properties (For Material ≤ 100 mm)** **A. Physical Properties (Typical)** * **Density:** 7.85 g/cm³ (0.284 lb/in³) * **Elastic Modulus:** 200 GPa (29,000 ksi) * **Poisson's Ratio:** 0.30 * **Coefficient of Thermal Expansion:** 11.7 x 10⁻⁶ /K (70-200°F) **B. Mechanical Properties (Minimum Required per ASTM A709)** | Property | Grade 50 (345) | Grade 50W (345W) | Test Condition | | :--- | :--- | :--- | :--- | | **Yield Strength (min)** | 345 MPa (50 ksi) | 345 MPa (50 ksi) | At room temperature | | **Tensile Strength** | 450 MPa (65 ksi) min | 485 MPa (70 ksi) min | At room temperature | | **Elongation (in 200 mm)** | 21% min | 21% min | | | **Elongation (in 50 mm)** | 24% min | 24% min | | | **Charpy V-Notch Impact Energy**| **Required** | **Required** | **Key differentiator from A572.** | | **Test Temperature** | Often 21°C (70°F) or 0°C (32°F) | Often -12°C (10°F) or lower | Specified by the buyer based on service location. | | **Minimum Energy** | 27 J (20 ft-lbf) typical | 27 J (20 ft-lbf) typical | For example, at 0°C for Zone 2. | ### **3. Product Applications** These grades are the workhorses of modern structural engineering, particularly in transportation infrastructure. * **Bridge Construction (Primary Application):** * **Grade 50:** Main load-carrying members in painted bridges – girders (I-beams, box girders), floor beams, cross-frames, and diaphragms. * **Grade 50W:** **Unpainted (weathering) bridges.** Used for exposed girders and structures where the aesthetic of the rust-like patina is desired and maintenance access is difficult. Commonly used for highway overpasses, pedestrian bridges, and rural bridges. * **Other Structural Applications:** * Building frames where high strength-to-weight ratio is beneficial. * Support structures for heavy equipment. * Transmission towers and electrical substation structures. * Barges and shipbuilding components. ### **4. International Standards & Designations** ASTM A709 is the dominant specification for bridge steel in North America. Close equivalents exist in other systems, but direct substitution requires careful review of property and testing requirements. | Standard System | Grade 50 Equivalent | Grade 50W Equivalent | Notes | | :--- | :--- | :--- | :--- | | **ASTM (USA)** | **A709-50** | **A709-50W** | The primary specification. | | **AASHTO (USA)** | **M270 Grade 50** | **M270 Grade 50W** | Identical to ASTM A709 for bridge construction; mandated by most US State DOTs. | | **CSA (Canada)** | **G40.21 350W** | **G40.21 350A** (Cor-ten-type) | CSA 350W (yield in MPa) is similar to Grade 50. CSA 350A is a weathering steel. | | **EN (Europe)** | **S355J2/N** | **S355J0W / S355J2W** | EN 10025-2 (S355) and EN 10025-5 (Weathering). S355 has a 355 MPa yield strength. | | **JIS (Japan)** | **SM490YA** | **SMA490AW** | JIS G3106 / G3114. SMA series are weathering steels. | | **ISO** | **ISO 630-2: E355** | **ISO 4952: E355WP** | International standardized equivalents. | ### **Key Features & Selection Guide** * **Toughness:** A709 mandates Charpy V-Notch testing, making it superior to basic structural specs (like A572 Gr. 50) for fracture-critical applications like bridges. * **Weathering Steel (50W):** Use where a permanent, maintenance-free finish is acceptable. Not recommended for consistently wet, salt-laden (coastal/marine), or highly industrial (high SO₂) environments without protection. * **Weldability:** Both grades exhibit excellent weldability due to controlled carbon content and CEV (Carbon Equivalent Value). Grade 50W, with its typically lower carbon, is often easier to weld. * **Availability:** Grade 50 is the most widely available high-strength structural steel. Grade 50W is also commonly stocked in major markets. ### **Summary** **ASTM A709 Grades 50 and 50W (≤ 100 mm)** represent the standard for high-performance, **toughness-guaranteed structural steels** in bridge and construction applications. **Grade 50** provides reliable high strength for painted structures, while **Grade 50W** offers the unique economic and aesthetic advantage of a maintenance-free weathering surface. The inclusion of mandatory impact testing in the A709 standard ensures these materials possess the necessary fracture resistance for the dynamic and safety-critical loads encountered in modern infrastructure, distinguishing them from ordinary structural steels. -:- For detailed product information, please contact sales. -: ASTM A709 Steel, grade 50 and 50W, ≤ 100 mm Specification Dimensions Size： Diameter 20-1000 mm Length <4140 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A709 Steel, grade 50 and 50W, ≤ 100 mm Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A709 Steel Flange, grade 50 and 50W, ≤ 100 mm -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A709 Steel Flange, grade 50 and 50W, ≤ 100 mm -:- For detailed product information, please contact sales. -:

Packing of ASTM A709 Steel Flange, grade 50 and 50W, ≤ 100 mm -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Flange drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 611 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition