AISI Type H43 Hot Work Tool Steel Flange (UNS T20843)

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 H43 Hot Work Tool Steel Flange (UNS T20843) Product Information -:- For detailed product information, please contact sales. -: AISI Type H43 Hot Work Tool Steel Flange (UNS T20843) Synonyms -:- For detailed product information, please contact sales. -:

AISI Type H43 Hot Work Tool Steel (UNS T20843) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI Type H43 (UNS T20843) Hot Work Tool Steel** **Overview** AISI Type H43 is a tungsten-based hot work tool steel designed for exceptional high-temperature strength, hardness retention, and resistance to thermal fatigue (heat checking). Its key characteristic is **secondary hardening**, a phenomenon where its hardness actually increases upon tempering at high temperatures (typically between 500°C - 600°C / 930°F - 1110°F). This makes H43 an outstanding choice for demanding applications involving high-pressure die casting, extrusion, and forging tools exposed to severe thermal cycling and abrasive wear. **Key Advantages** * **Superior Hot Hardness:** Maintains high hardness and strength at elevated service temperatures (up to ~650°C / 1200°F), outperforming many chromium-based hot work steels. * **Excellent Resistance to Thermal Fatigue & Heat Checking:** Withstands repeated heating and cooling cycles without developing a network of surface cracks. * **Good Wear Resistance & Erosion Resistance:** Ideal for applications involving abrasive materials or high-velocity molten metal flows. * **High Tempering Resistance:** Exhibits secondary hardening, allowing it to be tempered at high temperatures for optimal toughness and stability. **International Designations & Standards** * **AISI (USA):** H43 * **UNS (USA):** T20843 * **ASTM (USA):** A681 (specifies H43) * **DIN (Germany):** ~1.2606 (Similar tungsten hot-work steel, not a direct equivalent) * **JIS (Japan):** SKD6 (Similar tungsten hot-work steel) *(Note: While H43 is standardized in the U.S., exact equivalents in other standards may vary slightly. H43 is part of the tungsten-series hot work steels, distinct from the more common H11-H19 chromium series.)* --- #### **1. Chemical Composition (Typical, Weight %)** The high tungsten and molybdenum content are responsible for its exceptional hot hardness and secondary hardening. | Element | Content (%) | Role & Effect | | :--- | :--- | :--- | | **Carbon (C)** | 0.50 - 0.65 | Provides base hardness and wear resistance. | | **Tungsten (W)** | 8.50 - 10.00 | **Primary alloying element.** Forms stable carbides, enabling exceptional high-temperature strength and secondary hardening. | | **Chromium (Cr)** | 3.75 - 4.50 | Enhances hardenability, provides moderate corrosion/oxidation resistance, and contributes to wear resistance. | | **Molybdenum (Mo)**| 1.75 - 2.20 | Increases hardenability, refines grain structure, and works synergistically with tungsten for high-temperature performance. | | **Vanadium (V)** | 1.80 - 2.20 | Forms very hard, fine carbides that significantly improve wear resistance and grain refinement. | | **Silicon (Si)** | 0.80 - 1.20 | Improves oxidation resistance and strengthens the ferrite matrix. | | **Manganese (Mn)** | 0.15 - 0.40 | Aids in deoxidation during steelmaking and enhances hardenability. | | **Sulfur (S)** | ≤ 0.030 | Residual (kept low). | | **Phosphorus (P)** | ≤ 0.030 | Residual (kept low). | | **Iron (Fe)** | Balance | Base metal. | --- #### **2. Physical & Mechanical Properties** *Note: Properties are highly dependent on heat treatment condition.* | Property | Value / Description | Condition / Note | | :--- | :--- | :--- | | **Density** | ~8.0 g/cm³ (0.29 lb/in³) | Annealed | | **Melting Point** | ~1427°C (2600°F) | Approximate | | **Thermal Conductivity** | 26-30 W/m·K | At 20°C | | **Coefficient of Thermal Expansion** | 11.5 x 10⁻⁶/K | 20-600°C | | **Hardness (Annealed)** | ~207-235 HB | Brinell, typical annealed condition | | **Hardness (Hardened & Tempered)** | **45 - 55 HRC** | Typical working hardness range. Can achieve **up to ~58 HRC** via secondary hardening tempering. | | **Tempering Temperature Range** | **540°C - 650°C (1000°F - 1200°F)** | **Critical:** Peak secondary hardening occurs in this range. | | **Machinability** | 55-60% (of 1% carbon steel) | Annealed condition. Lower machinability compared to chromium hot-work steels. | --- #### **3. Product Applications** AISI H43 is primarily used for critical components in high-temperature metalforming processes where extreme hot hardness is required. * **High-Pressure Die Casting (HPDC):** * Cores and inserts for aluminum, magnesium, and brass die casting. * Nozzles, goosenecks, and plunger tips (especially for brass). * **Extrusion Tooling:** * Dies, dummy blocks, and liners for **copper and brass extrusion** (where temperatures are very high). * Mandrels and backers for heavy-duty extrusion. * **Hot Forging:** * Dies and inserts for forging highly abrasive or high-temperature alloys. * Piercing punches and wear pads. * **Other Applications:** * Glass molding tools. * Hot shear blades for cutting at high temperatures. * Components in plastic injection molding for abrasive or high-temperature engineering resins. --- #### **4. Heat Treatment Guidelines (Typical)** * **Preheating:** **Mandatory.** Double preheat at 650°C (1200°F) and 850°C (1560°F) to minimize thermal stress. * **Austenitizing (Hardening):** **1020°C - 1070°C (1870°F - 1960°F)**, followed by oil or salt bath quenching. **Note:** Very high hardening temperature requires careful furnace control. * **Tempering:** **Immediately after quenching.** Temper **at least twice** within the range of **540°C - 650°C (1000°F - 1200°F)**. Hold for 2 hours per inch of thickness. The hardness will peak (secondary hardening) typically between 570°C - 600°C (1060°F - 1110°F). **Disclaimer:** This information is for reference purposes. Always consult the specific material data sheet from your steel supplier and a professional heat treater for precise processing parameters for your application. -:- For detailed product information, please contact sales. -: AISI Type H43 Hot Work Tool Steel (UNS T20843) Specification Dimensions Size： Diameter 20-1000 mm Length <6703 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 H43 Hot Work Tool Steel (UNS T20843) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Type H43 Hot Work Tool Steel Flange (UNS T20843) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Type H43 Hot Work Tool Steel Flange (UNS T20843) -:- For detailed product information, please contact sales. -:

Packing of AISI Type H43 Hot Work Tool Steel Flange (UNS T20843) -:- 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 3174 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