JIS SKH52 Molybdenum High Speed Tool Steel Tube,Pipe

JIS SKH52 Molybdenum High Speed Tool Steel Tube Product Information -:- For detailed product information, please contact sales. -: JIS SKH52 Molybdenum High Speed Tool Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

JIS SKH52 Molybdenum High Speed Tool Steel Product Information -:- For detailed product information, please contact sales. -: # **JIS SKH52 Molybdenum High-Speed Tool Steel** **International Standard:** JIS G4403 (Japan Industrial Standard) - High-Speed Tool Steels --- ## **1. Overview** JIS SKH52 is a **molybdenum-based high-speed steel with 5% cobalt addition**, representing the Japanese equivalent to the globally recognized **AISI M35 grade**. This steel builds upon the balanced properties of SKH51 (M2) by incorporating cobalt, which significantly enhances **red hardness and high-temperature performance**. It is specifically engineered for applications requiring superior cutting edge retention during high-speed or heavy-duty machining operations where elevated temperatures at the tool tip are the primary limitation. SKH52 offers an optimal balance between the general-purpose utility of M2 and the extreme heat resistance of higher-cobalt grades like SKH55 (M42). --- ## **2. Chemical Composition (Typical Weight %)** | Element | Content (%) | | :------ | :---------- | | C | 0.85–0.95 | | Si | 0.20–0.45 | | Mn | 0.15–0.40 | | Cr | 3.80–4.50 | | Mo | 4.70–5.20 | | W | 5.90–6.70 | | V | 1.80–2.20 | | Co | 4.70–5.20 | | P (max) | 0.030 | | S (max) | 0.030 | **Balance:** Iron (Fe). **Key Characteristics:** The composition is essentially that of **SKH51 (M2) with the addition of approximately 5% cobalt**. The carbon content is typically at the higher end to optimize the formation of hard carbides and match the alloy content. --- ## **3. Physical & Mechanical Properties** ### **Physical Properties** - **Density:** ~8.2 g/cm³ - **Thermal Conductivity:** Slightly higher than SKH51 due to cobalt (~25 W/m·K at 20°C) - **Coefficient of Thermal Expansion:** ~11.3 ×10⁻⁶ /K (20–500°C) - **Specific Heat Capacity:** ~0.46 kJ/kg·K ### **Mechanical Properties (Heat-Treated)** - **Annealed Hardness:** ≤ 269 HB - **Typical Hardened & Tempered Hardness:** 64–66 HRC (can reach up to 67–68 HRC with optimized treatment) - **Red Hardness:** **Excellent** – Superior to SKH51; maintains hardness effectively up to ~620°C. - **Hot Hardness (at 600°C):** Typically ~56–58 HRC, significantly higher than standard M2. - **Transverse Rupture Strength:** Slightly lower than SKH51, typically ~3,200 – 3,400 MPa, due to the presence of cobalt. - **Toughness:** **Good to Moderate** – While still tough, the cobalt addition slightly reduces toughness compared to SKH51 at the same hardness level. --- ## **4. Heat Treatment Specifications** ### **1. Annealing** - **Temperature:** 850–900°C - **Process:** Heat uniformly, hold for 2–4 hours, furnace cool slowly (10–20°C/h) to about 600°C, then air cool. - **Resulting Hardness:** ≤ 269 HB ### **2. Hardening (Quenching)** - **Preheating:** **Critical.** - **First Preheat:** 400–500°C - **Second Preheat:** 800–850°C - **Austenitizing (Hardening) Temperature:** **1190–1220°C** (Similar to SKH51, but upper range is often used). - **Soaking Time:** 2–4 minutes per 25mm section. Careful control is needed to avoid grain growth while ensuring proper carbide solution. - **Quenching Medium:** Oil, air (for simple shapes), or salt bath. ### **3. Tempering** - **Crucial Requirement:** **Must be tempered immediately** after reaching hand-warm temperature (50–80°C). - **Temperature Range:** 540–580°C - **Cycle:** **Triple tempering is strongly recommended** to achieve maximum secondary hardness, stability, and to transform retained austenite. - **Process:** Heat to selected temperature, hold for 1–2 hours, air cool to room temperature. Repeat two more times. - **Hardness Peak:** Typically achieved after tempering at 560–570°C. --- ## **5. Key Features & Advantages** 1. **Enhanced Red Hardness & Hot Hardness:** The 5% cobalt addition dramatically improves the steel's ability to retain hardness and cutting edge integrity at high temperatures generated during machining. 2. **Improved High-Speed Machining Performance:** Allows for higher cutting speeds and feeds compared to standard M2 (SKH51) when machining hard or gummy materials. 3. **Good Wear Resistance:** Inherits the excellent wear resistance from the M2 base composition, courtesy of its molybdenum, tungsten, and vanadium carbides. 4. **Maintains Good Toughness:** While slightly less tough than SKH51, it retains sufficient toughness for a wide range of applications, including moderately interrupted cuts. 5. **Superior Grindability:** Cobalt improves thermal conductivity, which helps dissipate grinding heat, often resulting in better grindability than SKH51 at high hardness levels. --- ## **6. Typical Applications** SKH52 is the **premium upgrade choice** when SKH51 (M2) reaches its thermal limits. It is used for demanding machining operations requiring a balance of heat resistance and toughness. ### **Primary Cutting Tool Applications:** - **High-Performance Drills:** Twist drills and deep-hole drills for stainless steels, high-temp alloys, and abrasive materials. - **Advanced End Mills:** For machining tough alloys (e.g., Inconel, titanium, hardened steels) at higher speeds. - **Gear Hobs & Shaper Cutters:** For cutting hardened gears where tool tip temperatures are high. - **Broaches:** For precision finishing of high-strength materials. - **Milling Cutters & Inserts:** Face mills and slotting cutters for heavy-duty milling. - **Form Tools & Thread Rolling Dies:** Requiring high wear and temperature resistance. ### **Industries Served:** - Aerospace component manufacturing - Automotive (performance and transmission parts) - Die & mold making (machining pre-hardened steels) - General machining of difficult-to-cut materials --- ## **7. International Standard Equivalents** | Standard | Grade Designation | Notes | | :--------------- | :------------------ | :----------------------------------------- | | **JIS** | SKH52 | Original specification (JIS G4403) | | **AISI/SAE (USA)**| M35 | **Direct Equivalent** | | **DIN (Germany)** | 1.3243 / HS6-5-2-5 | European standard equivalent | | **ISO** | HS6-5-2-5 | International designation | | **GB (China)** | W6Mo5Cr4V2Co5 | Chinese equivalent | | **UNS** | T11335 | Unified Numbering System | | **AFNOR (France)**| Z90WDCV 06-05-04-02 | French standard (close variant) | --- ## **8. Machining & Fabrication Guidelines** ### **Machining (In Annealed State):** - Similar to SKH51. Use carbide tools with moderate speeds and feeds. - The annealed structure may be slightly tougher due to cobalt. ### **Grinding:** - **Good Grindability:** Cobalt aids in heat dissipation. - **Wheel Choice:** Aluminum oxide (Al₂O₃) or Cubic Boron Nitride (CBN) wheels are suitable. - **Practice:** Use sharp wheels and adequate coolant. The risk of grinding burns is slightly reduced compared to SKH51 at equivalent hardness. ### **Electrical Discharge Machining (EDM):** - Commonly used. The post-EDM white layer **must be removed** by polishing or a low-temperature stabilization treatment. ### **Welding:** - Generally not advised. If repair is necessary, it requires high preheat (450-550°C), specialized filler rods (matching HSS grade), and immediate post-weld tempering. --- ## **9. Surface Treatment** SKH52 is an **excellent candidate for advanced surface treatments**, which synergize with its high base performance. 1. **Nitriding:** Performed at low temperatures (e.g., 480–520°C) to create a hard, wear-resistant case without affecting the core hardness. 2. **PVD Coatings (TiAlN, AlCrN, TiSiN):** These high-temperature coatings are particularly effective on SKH52. They provide a thermal barrier, reduce friction, and drastically increase tool life in demanding dry or high-speed machining applications. --- ## **10. Summary** JIS SKH52 (AISI M35) occupies a critical **sweet spot in the high-speed steel family**. It delivers a **significant performance boost in red hardness over the ubiquitous SKH51/M2**, enabling higher productivity and the machining of more challenging materials, **without the drastic cost increase or toughness reduction associated with ultra-high-cobalt grades like SKH55/M42 (8-10% Co)**. It is the **strategic choice** when: * Standard M2 tools fail due to edge softening. * Operations involve continuous cuts generating high heat. * A balance between heat resistance, wear resistance, and reasonable toughness is paramount. * The workpiece material is a high-strength alloy, stainless steel, or moderately abrasive material. In essence, **SKH52 is the "high-performance daily driver" of high-speed steels**, offering a reliable and cost-effective upgrade path for applications that push standard M2 beyond its limits. -:- For detailed product information, please contact sales. -: JIS SKH52 Molybdenum High Speed Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6812 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. -: JIS SKH52 Molybdenum High Speed Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SKH52 Molybdenum High Speed Tool Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SKH52 Molybdenum High Speed Tool Steel Tube -:- For detailed product information, please contact sales. -:

Packing of JIS SKH52 Molybdenum High Speed Tool Steel Tube -:- 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 Tube 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 3283 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