AISI Type P20 Mold Steel Flange (UNS T51620)

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. -: AISI Type P20 Mold Steel Flange (UNS T51620) Product Information -:- For detailed product information, please contact sales. -: AISI Type P20 Mold Steel Flange (UNS T51620) Synonyms -:- For detailed product information, please contact sales. -:

AISI Type P20 Mold Steel (UNS T51620) Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI Type P20 Mold Steel (UNS T51620)** ## **Overview** **AISI P20 (UNS T51620)** is a **versatile, low-alloy, chromium-molybdenum mold steel** supplied in the **pre-hardened condition**. It is the **most widely used mold steel globally** for plastic injection molding and low-pressure die casting. Renowned for its excellent balance of machinability, polishability, weldability, and uniform hardness through thick sections, P20 eliminates the need for heat treatment by the mold maker, significantly reducing lead time and cost. Its consistent performance and reliability have made it the industry standard for a vast range of mold applications, from small precision components to large automotive panels. ## **1. Chemical Composition (Nominal %)** The composition of P20 is optimized for good hardenability, toughness, and polishability in the pre-hardened state. | Element | Content (%) | Primary Function | |---------|------------|------------------| | **Carbon (C)** | 0.28 - 0.40 | Provides core strength and hardness; balanced to ensure toughness and weldability. | | **Manganese (Mn)** | 0.60 - 1.00 | Enhances hardenability and strength. | | **Silicon (Si)** | 0.20 - 0.80 | Deoxidizer and strengthens the matrix. | | **Chromium (Cr)** | 1.40 - 2.00 | **Key element.** Provides hardenability, improves wear resistance, and contributes to polishability. | | **Molybdenum (Mo)** | 0.30 - 0.55 | **Key element.** Increases hardenability (especially in thick sections), improves toughness, and enhances tempering resistance. | | **Sulfur (S)** | ≤ 0.030 | Typically low. Some modified versions (P20S) have added sulfur for improved machinability. | | **Phosphorus (P)** | ≤ 0.030 | Residual impurity (kept low). | | **Iron (Fe)** | Balance | Base metal. | **Key Chemistry Note:** The **chromium-molybdenum synergy** provides deep and uniform hardening with air quenching or oil quenching at the mill, resulting in the uniform pre-hardened condition. The **moderate carbon content** is critical: high enough to achieve a useful working hardness (~30 HRC), but low enough to maintain good toughness, machinability, and, most importantly, **excellent weldability** for mold repairs and modifications. ## **2. Physical & Mechanical Properties (Pre-Hardened Condition)** P20 is universally supplied pre-hardened to a specific hardness range, typically 28-32 HRC or 30-34 HRC. | Property | Typical Value (Pre-Hardened @ ~30 HRC) | |----------|----------------------------------------| | **Density** | 7.82 g/cm³ | | **Melting Point** | ~1490°C (2715°F) | | **Thermal Conductivity** | ~36 W/m·K at 20°C | | **Coefficient of Thermal Expansion** | 12.5 × 10⁻⁶/K (20-100°C) | | **Modulus of Elasticity** | 205 GPa (29.7 × 10⁶ psi) | | **Hardness (Supplied)** | **28-32 HRC** (Brinell 285-325 HB). Higher hardness variants (e.g., P20+Ni, ~35 HRC) are available. | | **Tensile Strength** | ~1000-1100 MPa (145-160 ksi) | | **Yield Strength (0.2% Offset)** | ~950-1050 MPa (138-152 ksi) | | **Elongation** | ~12-15% | | **Reduction of Area** | ~35-45% | | **Impact Toughness (Charpy V-Notch)** | **~20-30 J (15-22 ft-lbf)** – Good toughness for a mold steel. | | **Machinability** | **Very Good** (~80-90% of 1212 steel baseline). The pre-hardened state is ideal for machining. | | **Polishability** | **Excellent.** Can achieve **SPI #1 (A-1) mirror finish** (≤ Ra 0.012 µm) with proper technique. | | **Weldability** | **Excellent.** Can be welded with common techniques (SMAW, GTAW) without preheating for minor repairs; preheat to 150°C (300°F) for major welding. | | **Texture & Etchability** | Excellent for photochemical etching (texturing) of mold surfaces. | ## **3. International Standards & Cross-References** P20 is the foundational grade with numerous direct international equivalents. Modified versions (e.g., with Nickel, Sulfur) are common. | Standard | Designation | Common Name / Notes | |----------|------------|---------------------| | **UNS** | T51620 | | | **AISI/ASTM (USA)** | P20 (ASTM A681) | **Standard P20.** | | **ISO (International)** | **35CrMo2** (ISO 4957) | Pre-hardened condition is implied. | | **DIN (Germany)** | **1.2311** (GS-738 / 40CrMnMo7-6) | The most common European equivalent, often supplied at ~290-330 HB. | | **DIN (Germany)** | **1.2312** (GS-738HH) | Free-machining variant with added sulfur (~0.06%). | | **JIS (Japan)** | **HPM2** (Commercial brand), **PX4/PX5** | | | **GB (China)** | **3Cr2Mo** (GB/T 1299) | The official Chinese standard equivalent. | | **BS (UK)** | **420M36** (Hardened & Tempered) | | | **Common Name** | **Pre-Hardened Plastic Mold Steel** | | ## **4. Product Applications** P20's primary domain is **plastic injection molding**, but its versatility extends to other tooling. **Primary Applications:** * **Plastic Injection Molds (Core & Cavity):** * The **#1 choice** for molds producing **consumer goods, automotive interior/exterior parts, electrical housings, medical devices, and toys**. * Suitable for all major engineering and commodity plastics (ABS, PP, PE, PC, Nylon, etc.). * **Low-Pressure Die Casting Dies** for zinc and aluminum. * **Compression and Transfer Molds** for rubber and thermosets. * **Blow Molds** for PET and other plastics. * **Mold Bases, Support Plates, and Ejector Housings.** * **Master Models and Patterns** for prototyping and soft tooling. * **General Fixtures and Machine Components** requiring good strength and stability. **Why Pre-Hardened?** Supplying P20 pre-hardened eliminates the risk, cost, and time associated with mold shop heat treatment (quenching/tempering), which can cause distortion and requires subsequent finish machining. Mold makers can **machine, polish, texture, and put the mold directly into service**. ## **5. Processing & Secondary Operations** * **Machining:** Machine in the pre-hardened state using standard tooling. Carbide tools are recommended for optimal life. Use positive rake angles and adequate coolant. * **Polishing:** Sequence: Start with coarse abrasives (e.g., 180 grit) and progress through finer grits (320, 400, 600, 800, 1200, diamond paste). The uniform microstructure allows for a flawless, pit-free mirror finish. * **Texturing (Etching):** Excellent for photochemical etching. The uniform hardness ensures consistent etch depth and sharp pattern definition. * **Welding:** For repair or modification: * **Minor Repairs:** Use matching electrodes (e.g., AWS ER70S-6 for GTAW) without preheat. * **Major Welds/Butt Welds:** Preheat to 150-200°C (300-390°F). Use low-hydrogen electrodes. Post-weld tempering at 250-300°C (480-570°F) is recommended for stress relief. * **Nitriding/Coatings:** Can be surface hardened via gas nitriding or coated with TiN, CrN, etc., to enhance wear and release properties for abrasive or corrosive plastics. ## **6. Key Advantages & Limitations** **Advantages:** * **Industry Standard:** Predictable performance, readily available in all sizes and shapes. * **Reduced Lead Time & Cost:** No heat treatment required by the mold maker. * **Excellent Polishability and Textureability.** * **Good Machinability and Weldability.** * **Uniform Properties** through thick sections (up to 400-500mm). * **Good Toughness** to withstand molding pressures and clamp forces. **Limitations:** * **Limited Wear Resistance:** Not suitable for highly abrasive plastics (e.g., fiberglass-filled) without surface hardening. * **Low Corrosion Resistance:** Will rust; not suitable for molding PVC or other corrosive materials without plating (e.g., chrome, nickel). * **Moderate Hot Hardness:** Not for high-temperature processes like hot runner systems or high-temperature thermosets; use H13 or hot work steels instead. * **Hardness Limitation:** Maximum usable hardness is in the low 30s HRC; for harder molds (≥ 40 HRC), through-hardening steels like S7 or H13 are chosen. --- **Disclaimer:** AISI P20 is supplied by numerous mills worldwide, and properties can vary slightly. Always specify the required hardness range (e.g., 29-31 HRC) and request mill certification. For corrosive or extremely abrasive molding applications, consider pre-hardened corrosion-resistant steels like 420SS (1.2083) or surface-treated P20. P20 remains the first and most logical choice for the majority of plastic injection molds due to its unparalleled balance of properties, processability, and economy. -:- For detailed product information, please contact sales. -: AISI Type P20 Mold Steel (UNS T51620) Specification Dimensions Size： Diameter 20-1000 mm Length <6747 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. -: AISI Type P20 Mold Steel (UNS T51620) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Type P20 Mold Steel Flange (UNS T51620) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Type P20 Mold Steel Flange (UNS T51620) -:- For detailed product information, please contact sales. -:

Packing of AISI Type P20 Mold Steel Flange (UNS T51620) -:- 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 3218 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