AISI 8720H Steel Flange

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 8720H Steel Flange Product Information -:- For detailed product information, please contact sales. -: AISI 8720H Steel Flange Synonyms -:- For detailed product information, please contact sales. -:

AISI 8720H Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 8720H Steel** #### **1. Overview** AISI 8720H is a **hardenability-controlled (H-grade) boron-modified nickel-chromium-molybdenum alloy steel**, representing the premium, consistency-guaranteed variant of the standard AISI 8720. This steel combines the **cost-effective hardenability enhancement of boron** with the **stringent batch-to-batch consistency** of the H-grade certification system. Engineered for high-volume manufacturing, it delivers **reliable and predictable core properties** after carburizing heat treatment, ensuring uniform performance across production lots. AISI 8720H provides an optimal balance of **deep hardenability, good core strength, and economic alloy design**, making it a preferred choice for cost-conscious yet quality-critical applications requiring guaranteed material consistency. #### **2. International Standards & Designations** This H-grade boron steel conforms to standards that govern both its composition and its guaranteed hardenability range. | Region/System | Standard Designation | Title / Purpose | | :--- | :--- | :--- | | **USA (AISI/SAE)** | **AISI 8720H, SAE J404 & SAE J1268** | Chemical Composition & Hardenability Bands | | **USA (ASTM)** | **ASTM A304** | Standard Specification for Steel Bars Subject to End-Quench Hardenability Requirements | | **USA (ASTM)** | **ASTM A914/A914M** | Steel Bars Subject to Restricted Hardenability Bands | | **UNS Number** | **H87200** | Unified Numbering System for H-Steels | | **Europe (EN)** | **20NiCrMoS2-2H (+B)** | Hardenability-controlled Boron-Treated Equivalent | | **Boron Steel Specific** | **SAE J406** | Hardenability Bands for Boron Steels | | **Heat Treatment** | **SAE AMS-H-6875** | Heat Treatment of Steel, General Requirements | #### **3. Chemical Composition & Hardenability Guarantee** The composition is tightly controlled, with boron as the key differentiating element and the entire chemistry optimized to meet precise H-band specifications. **Core Composition (% by Weight, AISI 8720H):** | Element | Content Range | Metallurgical Significance | | :--- | :--- | :--- | | **Carbon (C)** | 0.17 - 0.23 | Provides base core strength; tightly controlled for H-band consistency. | | **Manganese (Mn)** | 0.70 - 0.95 | Enhances hardenability; range adjusted for predictable Jominy curve. | | **Phosphorus (P)** | ≤ 0.035 | Impurity control. | | **Sulfur (S)** | ≤ 0.040 | Impurity control; sometimes optimized for machinability. | | **Silicon (Si)** | 0.15 - 0.35 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | 0.35 - 0.75 | Enhances core toughness; content stabilized for hardenability consistency. | | **Chromium (Cr)** | 0.35 - 0.65 | Increases hardenability; promotes wear-resistant carbides. | | **Molybdenum (Mo)** | 0.20 - 0.30 | Strong hardenability element; suppresses temper embrittlement. | | **Boron (B)** | **0.0005 - 0.003** | **Critical Hardenability Intensifier:** Significantly boosts hardenability at low cost. Its effect is maximized and stabilized through precise control of protecting elements (e.g., Ti, Al). | | **Titanium (Ti)** | Often added (~0.02%) | **Essential for Boron Efficacy:** Forms TiN, protecting soluble boron and ensuring consistent hardenability response. | **Key Feature: Guaranteed Hardenability Band (with Boron Effect)** The steel is supplied with certified Jominy end-quench test results guaranteed to fall within a specified narrow band. This certification **includes the potent effect of boron**, guaranteeing a predictable and uniformly deep hardening response. It ensures core hardness after heat treatment will have minimal lot-to-lot variation, typically within ±3 HRC for a given section size. #### **4. Mechanical & Physical Properties** *Properties are process-dependent. The following represents typical achievable ranges.* **As-Supplied (Annealed) Properties:** * **Hardness:** **149 - 197 HB** (Brinell) * **Tensile Strength:** **520 - 690 MPa** (75 - 100 ksi) * **Machinability:** **~60%** of B1112 steel. **Properties After Case Hardening (Carburized & Hardened):** * **Surface (Case) Properties:** * **Hardness:** **58 - 63 HRC** * **Effective Case Depth:** Can achieve greater depths more consistently than non-H grades due to guaranteed hardenability. * **Core Properties (H-Grade Advantage):** * **Hardness:** **32 - 45 HRC** (Predictable within narrow range). * **Tensile Strength:** **950 - 1300 MPa** (138 - 189 ksi) * **Yield Strength:** **750 - 1100 MPa** (109 - 160 ksi) * **Impact Toughness:** Good, maintained by nickel content. * **Section Size Capability:** The boron-enhanced, H-guaranteed hardenability allows reliable hardening of larger sections than possible with 8620H of similar alloy base. **Physical Properties (Core):** * **Density:** **7.85 g/cm³** * **Modulus of Elasticity:** **205 GPa** * **Coefficient of Thermal Expansion:** **12.5 × 10⁻⁶/°C** #### **5. Product Applications** AISI 8720H is specified for high-volume, cost-sensitive components where guaranteed core consistency and good hardenability are required without the expense of higher nickel/chromium grades. * **High-Volume Automotive Gearing:** Transmission gears, differential gears, and pinions for passenger cars and light trucks where production consistency is critical. * **Agricultural & Off-Highway Equipment:** Gears, shafts, and drive components for tractors, combines, and utility vehicles. * **Industrial Gearboxes:** Medium-duty gears for conveyors, pumps, and general industrial machinery produced in large batches. * **Bearing Components:** Races and rollers for mass-produced, medium-duty bearings. * **Hydraulic Components:** Gears and shafts in high-volume hydraulic pump and motor production. * **Fasteners:** High-strength, case-hardened bolts and pins for automotive and machinery assembly. #### **6. Key Characteristics & Advantages** * **Cost-Effective, Guaranteed Hardenability:** The **primary value proposition.** Boron provides deep hardenability at low alloy cost, while the H-grade certification ensures this benefit is delivered consistently in every production lot. * **Superior Production Consistency:** Eliminates the risk of hardenability variation common in standard boron steels, leading to uniform core hardness, predictable distortion, and stable heat treatment processes. * **Reduced Quality Risk & Scrap:** The guaranteed H-band virtually eliminates rejects due to insufficient core hardness in finished parts, offering significant savings in high-volume production. * **Excellent Value for Performance:** Delivers a hardenability profile often comparable to more expensive alloy grades (e.g., 8620H/8622H) but at a lower material cost, optimized for cost-driven designs. * **Good Machinability:** In the annealed condition, it offers good productivity in high-volume CNC machining operations. * **Design Flexibility:** The reliable hardenability allows for the design of larger or more complex sections with confidence in achieving target core properties. **Process Considerations:** * **Boron Protection:** Consistent response relies on adequate titanium/aluminum to protect boron from forming ineffective oxides/nitrides. * **Quenching:** Requires adequate quench severity (typically oil) to realize the full boron hardenability benefit. * **Not for Nitriding:** Boron can lead to brittle nitrided cases; not recommended for nitriding processes. * **Weldability:** Requires caution; preheat and low-hydrogen processes are essential to avoid cracking in the heat-affected zone. **Conclusion:** **AISI 8720H is a strategically engineered material that maximizes value through intelligent metallurgy and guaranteed quality control.** It successfully marries the **economic efficiency of boron hardenability** with the **production reliability of H-grade certification.** This makes it an ideal choice for manufacturers who must balance stringent performance and consistency requirements with aggressive cost targets. For high-volume applications in the automotive, agricultural, and general industrial sectors, where every component must perform identically and production yields are paramount, AISI 8720H provides a dependable, high-value solution. It exemplifies how modern steelmaking can deliver premium consistency in a cost-optimized alloy, ensuring quality and predictability without unnecessary material expense. -:- For detailed product information, please contact sales. -: AISI 8720H Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5748 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 8720H Steel Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 8720H Steel Flange -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 8720H Steel Flange -:- For detailed product information, please contact sales. -:

Packing of AISI 8720H Steel Flange -:- 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 2219 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