JIS SKS3 Oil-hardening Cold Work Tool Steel Wire

JIS SKS3 Oil-hardening Cold Work Tool Steel Wire Product Information -:- For detailed product information, please contact sales. -: JIS SKS3 Oil-hardening Cold Work Tool Steel Wire Synonyms -:- For detailed product information, please contact sales. -:

JIS SKS3 Oil-hardening Cold Work Tool Steel Product Information -:- For detailed product information, please contact sales. -: # **JIS SKS3 Oil-Hardening Cold Work Tool Steel** **International Standard:** JIS G4404 (Japan Industrial Standard) - Tool Steels --- ## **1. Overview** JIS SKS3 is a **medium-carbon, low-alloy oil-hardening cold work tool steel** characterized by its **balanced combination of hardness, toughness, and minimal distortion during heat treatment**. As part of the SKS series, it offers slightly lower carbon content than SKS2, providing improved toughness while maintaining good wear resistance. SKS3 is particularly valued for applications requiring reliable performance with good dimensional stability and is often considered a versatile general-purpose cold work tool steel. --- ## **2. Chemical Composition (Typical Weight %)** | Element | Content (%) | | :------ | :---------- | | C | 0.85–0.95 | | Si | 0.10–0.30 | | Mn | 0.90–1.20 | | Cr | 0.50–1.00 | | W | 0.50–1.00 | | V | 0.10–0.25 | | P (max) | 0.030 | | S (max) | 0.030 | **Balance:** Iron (Fe). **Key Characteristics:** SKS3 features a **moderate carbon content (0.85–0.95%)** balanced with tungsten and chromium for hardenability and wear resistance. The composition is optimized to provide a good balance between hardness (for wear resistance) and toughness (for impact resistance), with oil-hardening characteristics that minimize distortion. --- ## **3. Physical & Mechanical Properties** ### **Physical Properties** - **Density:** ~7.83 g/cm³ - **Thermal Conductivity:** ~46 W/m·K (at 20°C) - **Coefficient of Thermal Expansion:** ~12.4 ×10⁻⁶ /K (20–200°C) - **Specific Heat Capacity:** ~0.46 kJ/kg·K - **Modulus of Elasticity:** ~210 GPa ### **Mechanical Properties (Heat-Treated)** - **Annealed Hardness:** 183–223 HB - **Hardened & Tempered Hardness:** **56–61 HRC** (typical working range) - **Tensile Strength:** ~1900–2100 MPa (at 59 HRC) - **Yield Strength:** ~1700–1900 MPa - **Elongation:** ~6–10% - **Impact Toughness (Charpy):** **Very Good** – Better than SKS2, typically 15–25 J - **Wear Resistance:** **Good to Very Good** – Slightly less than SKS2 but adequate for most applications - **Compressive Strength:** ~2400–2700 MPa - **Fatigue Strength:** Good --- ## **4. Heat Treatment Specifications** ### **1. Annealing** - **Temperature:** 750–800°C - **Process:** Heat uniformly, hold for 2–4 hours, furnace cool slowly (≤ 20°C/h) to 550°C, then air cool - **Resulting Hardness:** 183–223 HB - **Spheroidize Annealing:** 760–780°C, hold 4–6 hours, cool at 10°C/h to 600°C (optimal for machining) ### **2. Stress Relieving** - **Temperature:** 600–650°C - **Hold Time:** 1–2 hours per 25mm thickness - **Purpose:** Reduce machining stresses, minimize distortion ### **3. Hardening (Quenching)** - **Preheating:** Recommended for uniform heating - **First Preheat:** 400–500°C (optional for simple shapes) - **Second Preheat:** 700–750°C (recommended) - **Austenitizing Temperature:** **780–850°C** (typically 800–830°C) - **Soaking Time:** 20–30 minutes per 25mm at temperature - **Quenching Medium:** **Oil** (warm oil at 40–80°C recommended) - **Quench Temperature:** From austenitizing temperature to 50–70°C ### **4. Tempering** - **Immediate Tempering Required:** Begin when tool reaches 50–80°C - **Temperature Range:** - **150–250°C:** For maximum hardness (58–61 HRC) - **250–400°C:** For balanced properties (56–59 HRC) - **400–550°C:** For maximum toughness (52–56 HRC) - **Hold Time:** 1–2 hours per 25mm thickness, minimum 1 hour - **Cycles:** Single temper usually sufficient; double tempering for precision tools --- ## **5. Key Features & Advantages** 1. **Excellent Toughness-Hardness Balance:** Optimized carbon content provides better impact resistance than SKS2 while maintaining good hardness 2. **Minimal Distortion:** Oil quenching results in good dimensional control 3. **Good Machinability:** In annealed condition, comparable to other SKS grades 4. **Versatile Performance:** Suitable for a wide range of cold work applications 5. **Reliable Heat Treatment:** Forgiving heat treatment characteristics 6. **Good Wear Resistance:** Adequate for many industrial applications 7. **Cost-Effective:** Economical choice for many tooling needs **Limitations:** - **Lower Maximum Hardness:** Cannot achieve the highest hardness levels of SKS2 - **Moderate Wear Resistance:** Less wear resistant than higher-alloy steels - **Limited Hot Hardness:** Not suitable for high-temperature applications --- ## **6. Typical Applications** SKS3 is widely used for **various cold work tooling applications** where a balance of toughness and wear resistance is important. ### **Cutting & Shearing Tools:** - **Hand Tools:** Punches, chisels, screwdrivers - **Cutting Blades:** For paper, leather, textiles, plastics - **Shear Blades:** For sheet metal cutting - **Knives:** Industrial cutting knives ### **Forming & Stamping Tools:** - **Punches and Dies:** For blanking, piercing, and forming operations - **Bending Tools:** Press brake dies - **Drawing Dies:** For shallow to medium drawing - **Embossing Dies:** For decorative work ### **Measuring & Precision Tools:** - **Gauges:** Plug gauges, ring gauges, thread gauges - **Templates:** For inspection and layout - **Machine Components:** Bushings, wear plates, guide pins ### **Woodworking Tools:** - **Planer Blades:** For woodworking machinery - **Carving Tools:** For wood and pattern making - **Saw Blades:** Circular saw blades for non-ferrous materials ### **Special Applications:** - **Plastic Mold Components:** For non-abrasive plastics - **Thread Rolling Dies:** For softer materials - **Knurling Tools:** For producing patterns on surfaces - **Lathe Tools:** For soft materials --- ## **7. International Standard Equivalents** | Standard | Grade Designation | Notes | | :--------------- | :------------------ | :----------------------------------------- | | **JIS** | SKS3 | Original specification (JIS G4404) | | **AISI/SAE (USA)**| O2 | **Direct Equivalent** (Oil-hardening 2) | | **DIN (Germany)** | 1.2842 | Close equivalent | | **ISO** | 90MnWCrV2 | International designation | | **BS (UK)** | BO2 | British standard | | **GB (China)** | 9Mn2V | Similar characteristics | | **UNS** | T31502 | Unified Numbering System | --- ## **8. Machining & Fabrication Guidelines** ### **Machining (In Annealed State):** - **Excellent Machinability:** Similar to other SKS grades - **Tooling:** High-speed steel tools work well; carbide for production - **Cutting Speeds:** Can use moderate to high speeds - **Feeds:** Moderate feeds with good chip control - **Surface Finish:** Produces good surface finishes ### **Grinding:** - **Good Grindability:** Responds well to standard grinding operations - **Wheel Selection:** Aluminum oxide wheels (A46-JV or similar) - **Coolant:** Use coolant for best results and to prevent overheating - **Parameters:** Standard grinding parameters suitable ### **Electrical Discharge Machining (EDM):** - **Suitable:** Can be EDMed in hardened or annealed state - **Post-EDM:** Temper at 150–180°C to relieve white layer stresses - **Surface Integrity:** Good with proper parameters ### **Welding:** - **Possible with Care:** Can be welded using appropriate techniques - **Preheat:** 200–300°C recommended - **Filler Material:** Use matching or similar composition filler - **Post-Weld:** Stress relieve or re-harden for best results --- ## **9. Surface Treatment** ### **1. Nitriding:** - **Effective Treatment:** Improves surface hardness and wear resistance - **Process:** Gas or plasma nitriding at 500–550°C - **Case Depth:** 0.1–0.3 mm typical - **Surface Hardness:** 700–900 HV - **Benefits:** Extends tool life without affecting core toughness ### **2. Carburizing:** - **Occasionally Used:** For special applications requiring harder case - **Process:** Pack or gas carburizing - **Result:** Creates high-carbon case on medium-carbon core ### **3. Coatings:** - **Phosphate Coating:** For corrosion resistance and lubricity - **Chrome Plating:** Hard chrome for wear resistance (0.01–0.05 mm) - **PVD Coatings:** TiN, TiCN for specialized applications --- ## **10. Performance Comparison** ### **Within SKS Oil-Hardening Series:** | Property | SKS3 (O2) | SKS2 (O1) | SKS21 (L6-type) | SKS4 (W1-type) | |-----------------------|--------------|--------------|-----------------|----------------| | **Carbon Content** | 0.85–0.95% | 0.95–1.10% | 0.70–0.80% | 1.00–1.10% | | **Typical Hardness** | 56–61 HRC | 57–62 HRC | 54–59 HRC | 58–63 HRC | | **Impact Toughness** | **Very Good**| Good | **Excellent** | Fair | | **Wear Resistance** | Good | **Best** | Good | Good | | **Machinability** | Excellent | Excellent | Excellent | Excellent | | **Distortion Control**| Very Good | Very Good | Very Good | Fair | ### **Compared to Other Cold Work Steels:** | Property | SKS3 (O2) | A2 (Air-hardening) | D2 (High-Carbon) | W1 (Water-hardening) | |-----------------------|--------------|---------------------|------------------|----------------------| | **Hardening Method** | Oil | Air | Air | Water | | **Distortion** | Low | Very Low | Very Low | High | | **Toughness** | Very Good | Good | Fair | Fair | | **Wear Resistance** | Good | Very Good | **Excellent** | Good | | **Machinability** | Excellent | Good | Fair | Excellent | | **Cost** | Low | Medium | High | Low | --- ## **11. Design Considerations** ### **Section Size Capability:** - **Fully Hardenable:** Up to approximately 30 mm diameter/thickness - **Surface Hardening:** Effective for sections up to 75 mm - **Large Tools:** Consider alternative grades for sections > 75 mm ### **Stress Management:** - **Radius Requirements:** Minimum 0.5 mm radius on all corners - **Uniform Sections:** Design for even wall thickness where possible - **Stress Relief:** Essential after rough machining of complex tools ### **Hardness Selection Strategy:** - **For General Purpose:** Temper at 200–300°C (57–59 HRC) - **For Impact Resistance:** Temper at 350–450°C (54–56 HRC) - **For Maximum Wear Resistance:** Temper at 150–200°C (59–61 HRC) ### **Dimensional Changes:** - **During Hardening:** Typically 0.06–0.14% growth - **During Tempering:** Minimal change - **Machining Allowance:** 0.1–0.2 mm per side for finish grinding --- ## **12. Quality Control** ### **Hardness Testing:** - **Rockwell C Scale:** For hardened material (multiple locations) - **Brinell:** For annealed material - **Superficial Rockwell:** For thin sections or case depth measurement ### **Microstructure Examination:** - **Annealed Condition:** Spheroidized carbides in ferritic matrix - **Hardened Condition:** Tempered martensite with fine carbides - **Grain Size:** ASTM 8 or finer preferred ### **Non-Destructive Testing:** - **Magnetic Particle Inspection:** For surface cracks - **Dye Penetrant Inspection:** For non-magnetic applications - **Dimensional Verification:** Critical for precision tools ### **Performance Validation:** - **Tool Life Testing:** For production applications - **Wear Testing:** For applications with specific requirements - **Fatigue Testing:** For cyclic loading applications --- ## **13. Summary & Selection Guidelines** JIS SKS3 (AISI O2) is a **well-balanced, versatile oil-hardening cold work tool steel** that offers an optimal compromise between hardness, toughness, and dimensional stability. ### **Select SKS3 When:** 1. A **balanced combination of hardness and toughness** is required 2. **Good dimensional stability** during heat treatment is important 3. Tools are subject to **moderate impact** as well as wear 4. **Cost-effectiveness** is a consideration 5. **Good machinability** facilitates tool manufacturing 6. **Reliable performance** in various cold work applications is needed 7. **Oil-hardening characteristics** are preferred over water hardening ### **Optimal Application Examples:** - **General-purpose punches and dies** for sheet metal work - **Hand tools** requiring good edge retention and toughness - **Forming tools** for medium-duty applications - **Cutting tools** for non-abrasive materials - **Gauges and measuring tools** requiring dimensional stability - **Prototype tooling** where balanced properties are advantageous ### **Consider Alternatives When:** - **Maximum wear resistance** is the primary requirement (consider SKS2 or higher-alloy steels) - **Exceptional toughness** is needed for heavy impact (consider SKS21) - **Extreme dimensional stability** is critical for complex tools (consider air-hardening grades) - **High-temperature operation** is involved (consider hot work steels) - **Maximum hardness** (>61 HRC) is required (consider higher-carbon grades) ### **Economic Advantages:** - **Competitive material cost** compared to other tool steels - **Reduced machining costs** due to excellent machinability - **Lower heat treatment costs** compared to some air-hardening grades - **Good tool life** for many applications, reducing replacement costs ### **Heat Treatment Flexibility:** SKS3 offers flexible heat treatment options allowing adjustment of properties: - **Lower tempering temperatures** for increased wear resistance - **Higher tempering temperatures** for increased toughness - **Forgiving hardening process** suitable for shops with basic equipment ### **Industry Preference:** SKS3 is particularly popular in: - **General tool and die shops** - **Maintenance and repair facilities** - **Educational institutions** - **Small to medium manufacturing operations** - **Industries requiring versatile, reliable tooling** ### **Final Recommendation:** JIS SKS3 remains a **highly practical and widely used cold work tool steel** that delivers reliable performance across a broad range of applications. Its balanced properties make it an excellent "default choice" for many tooling needs where specific extreme requirements (maximum wear resistance, maximum toughness, or maximum dimensional stability) are not paramount. For tool designers and manufacturers seeking a **versatile, economical, and reliable material** for general cold work applications, SKS3 offers proven performance with straightforward processing requirements. Its combination of good machinability, controllable heat treatment response, and balanced mechanical properties ensures its continued relevance in toolrooms and manufacturing facilities worldwide. When uncertain about specific material requirements or when designing tools for varied or unpredictable service conditions, SKS3 often provides a **safe and effective solution** that performs well across many common cold work applications. -:- For detailed product information, please contact sales. -: JIS SKS3 Oil-hardening Cold Work Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6822 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 SKS3 Oil-hardening Cold Work Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SKS3 Oil-hardening Cold Work Tool Steel Wire -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SKS3 Oil-hardening Cold Work Tool Steel Wire -:- For detailed product information, please contact sales. -:

Packing of JIS SKS3 Oil-hardening Cold Work Tool Steel Wire -:- 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 Wire 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 3293 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