AISI Type S7 Tool Steel Flange (UNS T41907)

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 S7 Tool Steel Flange (UNS T41907) Product Information -:- For detailed product information, please contact sales. -: AISI Type S7 Tool Steel Flange (UNS T41907) Synonyms -:- For detailed product information, please contact sales. -:

AISI Type S7 Tool Steel (UNS T41907) Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: AISI Type S7 Tool Steel (UNS T41907)** ## **Overview** **AISI S7 (UNS T41907)** is the premier **chromium-molybdenum air-hardening shock-resisting tool steel**, renowned worldwide for its **exceptional combination of high toughness and good wear resistance**. It represents the pinnacle of modern shock steel technology, offering **superior impact resistance, excellent dimensional stability during heat treatment, and reliable performance**. S7 is the benchmark against which other shock-resistant steels are measured, making it the first choice for the most demanding cold work applications where tools must withstand brutal impact without chipping or cracking. ## **1. Chemical Composition (Nominal %)** S7's chemistry is a masterful balance for achieving supreme toughness through air hardening. | Element | Content (%) | Primary Function | |---------|------------|------------------| | **Carbon (C)** | 0.45 - 0.55 | Provides the foundation for hardness and strength. Optimized to maximize toughness at high hardness levels. | | **Chromium (Cr)** | 3.00 - 3.50 | **Key element.** Provides deep hardenability for air hardening, improves wear resistance, and contributes to toughness. | | **Molybdenum (Mo)** | 1.30 - 1.80 | **Key element.** Dramatically increases hardenability, refines grain structure, and is a potent toughening agent. Critical for the air-hardening capability and high impact strength. | | **Silicon (Si)** | 0.20 - 0.35 | Provides solid solution strengthening and improves toughness. Kept moderate to optimize machinability and prevent decarburization issues. | | **Vanadium (V)** | ≤ 0.25 | Grain refiner; improves wear resistance and toughness by inhibiting grain growth. | | **Manganese (Mn)** | 0.20 - 0.90 | Supports hardenability and works as a deoxidizer. | | **Iron (Fe)** | Balance | Base metal. | **Key Chemistry Note:** The **synergistic combination of chromium (~3.25%) and molybdenum (~1.50%)** is the heart of S7. This duo provides exceptional **air hardenability**, allowing full hardening of large sections with minimal distortion and quench cracking risk. Molybdenum is particularly effective in promoting a fine, tough martensitic microstructure. The **moderate carbon content** is precisely tuned to deliver hardness in the mid-50s HRC range where toughness is maximized. ## **2. Physical & Mechanical Properties** *Typical properties in the hardened and tempered condition (54-57 HRC).* | Property | Typical Value / Condition | |----------|--------------------------| | **Density** | 7.80 g/cm³ (0.282 lb/in³) | | **Melting Point** | ~1515°C (2760°F) | | **Thermal Conductivity** | ~42 W/m·K (Moderate) | | **Coefficient of Thermal Expansion** | 11.5 × 10⁻⁶/K (20-100°C) | | **Modulus of Elasticity** | 205 GPa (29.7 × 10⁶ psi) | | **Annealed Hardness** | 192-229 HB | | **As-Quenched Hardness (Air)** | ~58-60 HRC | | **Hardened & Tempered Hardness** | **54-57 HRC** (The **optimum working range** for S7, where it exhibits its legendary toughness). | | **Tensile Strength** | ~1850-2000 MPa (268-290 ksi) at 56 HRC | | **Yield Strength (0.2% Offset)** | ~1650-1800 MPa (239-261 ksi) | | **Elongation** | ~12-14% | | **Reduction of Area** | ~35-45% | | **Impact Toughness (Charpy V-Notch)** | **Outstanding.** Typically **90-130 J (66-96 ft-lbf)** at 56 HRC. **This is among the highest impact resistance of any commercially available tool steel.** | | **Wear Resistance** | **Good.** Adequate for most impact tool applications; superior to S5. | | **Machinability (Annealed)** | Fair (approx. 55% of 1% carbon steel baseline). | | **Grindability** | Good. | | **Dimensional Stability** | **Excellent.** Minimal distortion and size change during air quenching. | ## **3. International Standards & Cross-References** S7 is a globally recognized and standardized premium grade. | Standard | Designation | |----------|------------| | **UNS** | T41907 | | **AISI/ASTM (USA)** | S7 (ASTM A681) | | **ISO (International)** | **~50CrMoV12-1** (ISO 4957: Tool steels) – A close functional match. | | **DIN (Germany)** | **1.2550** | | **BS (UK)** | **BS7** | | **JIS (Japan)** | **SKS8** (Note: SKS8 is similar but not always an exact 1:1 match). | | **GB (China)** | **5Cr3NiMoSiV** (A close equivalent, reflecting the Cr-Mo-V system) | | **Common Name** | **Chromium-Molybdenum Air-Hardening Shock Steel** | ## **4. Product Applications** S7 is the **go-to material** for critical applications where tool failure due to chipping or fracture is unacceptable. **Primary Applications:** * **Heavy-Duty Punching and Shearing:** * **Punches** and **dies** for cold forging, stamping, and hole punching in thick plate. * **Shear blades** for steel plate, bars, and structural shapes. * **Bolt cutters** and **cable cutters**. * **Chisels and Impact Tools:** * **Cold chisels** and **masonry chisels** for severe service. * **Demolition tool bits** (chipping hammers, scaling hammers). * **Driver bits** for high-torque impact wrenches. * **Die Casting and Forging Tooling:** * **Ejector pins**, **core pins**, and **inserts** for aluminum die casting (benefiting from its heat check resistance). * **Hot work chisels** and **hot punches** (for moderate temperatures). * **Plastic Injection Molds:** * **Mold components** subject to high impact or clamping stress, such as **interlocks**, **wear plates**, and **ejector sleeves**. * **Knives and Blades:** * **Severe-duty slitter knives** and **industrial cutting blades**. ## **5. Heat Treatment Guidelines** S7's air-hardening characteristic makes its heat treatment forgiving and reproducible. * **Annealing:** Heat to 815-845°C (1500-1550°F), slow furnace cool. Annealed hardness: 192-229 HB. * **Hardening:** 1. **Preheating:** Preheat to **650-700°C (1200-1290°F)**. This step is still important to minimize thermal stress, even for air hardening. 2. **Austenitizing:** Heat to **925-955°C (1695-1750°F)**. A common target is **940°C (1725°F)**. Soak for 30-45 minutes per inch of cross-section. 3. **Quenching:** **Cool in still or forced air.** For maximum hardenability in very thick sections (>6 inches), oil quenching can be used but is rarely necessary and increases distortion. * **Tempering (Critical for S7's Performance):** * **Temper immediately** after reaching near room temperature. * To achieve the optimal toughness-hardness balance (54-57 HRC), temper at **315-455°C (600-850°F)**. * **Double tempering is standard practice.** Hold for 2 hours per inch minimum per temper. This ensures complete stress relief and microstructure stabilization. * S7 exhibits a **strong secondary hardening peak** around **510-540°C (950-1000°F)**. Tempering in this range can achieve hardness up to ~58 HRC with still-excellent toughness, but the classic 54-57 HRC range is preferred for maximum impact resistance. ## **6. Key Advantages & Why It's the Benchmark** * **Unmatched Toughness at Usable Hardness:** Delivers the highest impact resistance in its class at a hardness (54-57 HRC) that provides excellent strength and moderate wear resistance. * **Air Hardening:** Provides **minimal distortion, excellent dimensional stability, and virtually no risk of quench cracking**. This simplifies tool design and reduces finishing costs. * **Consistent & Reproducible:** Heat treatment is less critical than with water- or oil-hardening grades, leading to more reliable results in production. * **Versatile Performer:** Excels in both cold work and moderate hot work applications. **Conclusion:** AISI S7 is the **definitive shock-resisting tool steel** for engineers and toolmakers who cannot afford failure. Its unparalleled combination of extreme toughness, dimensional stability, and good overall performance makes it the **first and most reliable choice** for the world's most demanding punching, shearing, and impact applications. While other steels may excel in one specific property, S7's balanced excellence across the board has secured its status as an industry standard for severe-duty tooling. --- **Disclaimer:** Although S7 is air hardening, proper preheating and controlled austenitizing are still essential for optimal properties and to prevent thermal shock. While its tempering response is wide, following the recommended ranges (especially double tempering) is critical to achieving its legendary toughness. For applications involving very high temperatures (>540°C / 1000°F), hot-work steels like H13 may be more appropriate. S7 is a premium material, and its cost is justified by its performance and reliability in critical applications. -:- For detailed product information, please contact sales. -: AISI Type S7 Tool Steel (UNS T41907) Specification Dimensions Size： Diameter 20-1000 mm Length <6764 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 S7 Tool Steel (UNS T41907) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI Type S7 Tool Steel Flange (UNS T41907) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI Type S7 Tool Steel Flange (UNS T41907) -:- For detailed product information, please contact sales. -:

Packing of AISI Type S7 Tool Steel Flange (UNS T41907) -:- 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 3235 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