JIS SKC24 Tool Steel Sheet,Plate

JIS SKC24 Tool Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: JIS SKC24 Tool Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

JIS SKC24 Tool Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Technical Datasheet: JIS SKC24 Low-Alloy Tool Steel** --- #### **1. Product Overview** **JIS SKC24** is a versatile **chromium-molybdenum-vanadium (Cr-Mo-V) low-alloy tool steel** specified under the Japanese Industrial Standard (JIS) G 4404. It is engineered as an **oil-hardening grade** that offers an excellent balance of **high hardenability, good toughness, and superior dimensional stability** compared to standard water-hardening steels. SKC24 features a carefully balanced alloy system designed to minimize distortion during heat treatment while providing enhanced wear resistance and edge-holding capability. This grade is particularly noted for its **consistent through-hardening characteristics** and **excellent machinability in the annealed condition**, making it a preferred choice for complex tools requiring precision and reliability. It serves as a high-performance upgrade from basic oil-hardening steels like SKC11 (O1) for demanding cold-work applications. --- #### **2. International Standard Cross-Reference** SKC24 is a well-established grade with close equivalents in major international standards, though with slight compositional variations. | Standard System | Equivalent / Similar Grade | Key Similarity / Note | | :--- | :--- | :--- | | **JIS G 4404 (Japan)** | **SKC24** | Defining Standard | | **ASTM (USA)** | **O6** (Graphitic) / Modified O2 | *Note: O6 is graphite-bearing; SKC24 is closer to a modified O2 with V* | | **DIN (Germany)** | **~1.2606 / 55NiCrMoV7** | Similar Ni-Cr-Mo-V system, but with higher Ni | | **BS (UK)** | **BO2 (Modified)** | Similar to oil-hardening, non-deforming type with V addition | | **AISI (USA)** | **(No direct equivalent)** | Functionally similar to a premium O2 variant | | **GB (China)** | **~CrWMnV / 9CrWMnV** | Similar alloying philosophy with V addition | | **ISO** | **~60WCrV8** | Similar alloying concept with Cr, W, V | **Note:** SKC24 is a uniquely balanced Japanese grade; its closest functional analogs are modified versions of O2-type steels with vanadium. --- #### **3. Chemical Composition (Typical, weight % per JIS G 4404)** The composition features a multi-alloy system with intentional vanadium addition for grain refinement and secondary hardening. | Element | Carbon (C) | Silicon (Si) | Manganese (Mn) | Chromium (Cr) | Molybdenum (Mo) | Vanadium (V) | Phosphorus (P) | Sulfur (S) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content (%)** | 0.85 - 0.95 | 0.10 - 0.40 | 1.20 - 1.60 | 0.80 - 1.20 | 0.20 - 0.40 | 0.05 - 0.15 | ≤ 0.030 | ≤ 0.030 | **Function of Key Alloying Elements:** * **Carbon (0.85-0.95%):** Provides the base for high hardness and carbide formation. * **Chromium (0.80-1.20%) & Molybdenum (0.20-0.40%):** Work synergistically to dramatically improve **hardenability** and promote through-hardening with minimal distortion during oil quenching. * **Manganese (1.20-1.60%):** Further enhances hardenability and contributes to solid solution strengthening. * **Vanadium (0.05-0.15%):** The key differentiating element. Forms fine, hard vanadium carbides that **refine grain size** during austenitizing, improving toughness and wear resistance. It also contributes to **secondary hardening** during tempering. --- #### **4. Physical & Mechanical Properties** * **Density:** ~7.85 g/cm³ * **Thermal Conductivity:** Moderate (approx. 40-45 W/m·K at 20°C). * **Thermal Expansion Coefficient:** ~11.5 x 10⁻⁶ /K (20-200°C). * **Machinability (Annealed State):** **Very Good.** One of its standout features; the balanced alloy system and typical spheroidized annealed structure allow for excellent machining performance. * **Hardenability:** **Excellent (Oil-Hardening).** Capable of through-hardening large cross-sections (up to ~100-125mm diameter) with uniform hardness in oil. Superior to SKC11. * **Primary Quenching Medium:** **Oil (medium-speed quenching oil).** This ensures minimal thermal stress and distortion. * **Dimensional Stability:** **Outstanding.** Exhibits extremely low distortion and volume change during heat treatment, making it ideal for precision tools. * **Typical Achievable Hardness:** * **Annealed State:** ~ 200 - 230 HB * **Hardened & Tempered State:** **60 - 63 HRC** (when tempered at 150-200°C). It maintains good hardness (~57-60 HRC) even when tempered at higher temperatures (250-300°C) for increased toughness. --- #### **5. Heat Treatment Guidelines** * **Forging:** Heat uniformly to 1050-900°C. Forge and cool slowly in furnace or insulating material. * **Annealing:** Heat to 760-790°C, slow furnace cool (≤15°C/hour) to 600°C, then air cool. Aim for a fine spheroidized carbide structure. * **Stress Relieving (after rough machining):** 600-650°C, slow cool. * **Hardening:** 1. **Preheat:** 650-700°C (strongly recommended to minimize thermal shock). 2. **Austenitizing:** **800-840°C.** The vanadium requires adequate temperature/time for carbide solutioning. Soak time: 20-30 minutes per inch. 3. **Quench:** Agitate in **well-circulated, medium-speed quenching oil** until the part reaches 50-80°C. * **Tempering:** **Perform immediately.** For best results, double temper. * **Tempering Range:** **150-300°C.** * **Typical Cycle:** 180-200°C for 1-2 hours, twice. This maximizes hardness and stability. * **Secondary Hardening:** A noticeable secondary hardening peak occurs around 250-300°C due to vanadium carbide precipitation, allowing for a good combination of hardness and toughness. --- #### **6. Product Applications** SKC24 is specified for high-quality, precision tools and dies where dimensional accuracy, wear life, and reliability are critical. * **Precision Cutting Tools:** **Complex form cutters, gear hobs, broaches, and reamers** requiring sharp edges and stability. * **Stamping & Forming Dies:** **High-precision blanking dies, progressive dies, bending dies, and fine blanking dies** for medium-to-high production runs. * **Molds:** **Plastic injection molds** for engineering plastics, requiring good polishability and wear resistance without the cost of high-alloy steels. * **Gauges & Measuring Instruments:** **Master gauges, thread rolling dies, and precision measuring components** where absolute dimensional stability is non-negotiable. * **Machine Tool Components:** **Cams, roller bearings, guide pins, and wear plates** in precision machinery. * **Knives & Blades:** **Industrial slitter knives, rotary cutters, and shear blades** for non-ferrous metals and textiles. --- #### **7. Advantages & Limitations** | Advantages | Limitations | | :--- | :--- | | • **Exceptional dimensional stability** with minimal distortion.
• **Excellent through-hardenability** for large and complex sections.
• **Superior machinability** in annealed state, reducing tooling costs.
• **Good combination of hardness and toughness**, especially when tempered in the secondary hardening range.
• **Predictable and reliable heat treatment response** with oil quenching.
• **Better wear resistance than standard O1/SKC11** due to vanadium carbides. | • **Lower wear resistance** compared to high-chromium (D2/SKD11) or powder metallurgy steels.
• **Limited hot hardness**; not suitable for high-speed cutting or hot work applications.
• **More expensive** than basic oil-hardening grades like SKC11.
• **Can be susceptible to decarburization** if not heat treated in a protective atmosphere (salt bath or vacuum recommended for critical parts). | --- #### **8. Comparative Selection Guide** * **vs. SKC11 (O1):** SKC24 offers **superior hardenability for larger sections, better toughness at equivalent hardness, and improved machinability.** It is the preferred choice for more critical, complex, or larger tools. * **vs. Air-Hardening Steels (A2/SKD12, D2/SKD11):** SKC24 has **easier heat treatment (oil vs. air/furnace cool)** and **better machinability**, but air-hardening grades offer **superior wear resistance (especially D2) and even better dimensional stability for massive dies.** * **vs. Shock-Resisting Steels (S7, etc.):** For pure impact applications, shock-resistant steels are tougher. SKC24 is better for **applications combining wear, precision, and moderate shock loading.** **Conclusion:** JIS SKC24 is a **premium-grade, low-distortion oil-hardening tool steel** that represents an optimal balance between processability and performance. Its sophisticated Cr-Mo-V alloy design makes it an **exceptional choice for demanding, precision cold-work tooling** where reliability, dimensional accuracy, and tool life are paramount. It successfully bridges the gap between standard oil-hardening grades and more expensive air-hardening steels, offering a compelling value proposition for toolmakers who require high performance without the complexity of air hardening. For critical dies, molds, and cutting tools that must be machined to precise dimensions and maintain them in service, SKC24 is a **highly respected and trusted material choice.** -:- For detailed product information, please contact sales. -: JIS SKC24 Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6797 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 SKC24 Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SKC24 Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SKC24 Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of JIS SKC24 Tool Steel Sheet/Plate -:- 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 Sheet/Plate 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 3268 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