JIS SK4 Water Hardening Tool Steel Sheet,Plate

JIS SK4 Water Hardening Tool Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: JIS SK4 Water Hardening Tool Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

JIS SK4 Water Hardening Tool Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Technical Datasheet: JIS SK4 Water-Hardening Tool Steel** **1. Product Overview** JIS SK4 is a high-carbon, non-alloy tool steel classified under the Japanese Industrial Standard (JIS) G 4401 for carbon tool steels. It is a **water-hardening grade**, known for its ability to achieve a very high surface hardness and excellent wear resistance after a straightforward water or brine quenching heat treatment. SK4 offers a favorable cost-to-performance ratio for applications requiring a hard, durable edge where extreme shock resistance or high-temperature performance is not critical. Its primary limitation is its relatively shallow hardening depth and higher risk of distortion or cracking during quenching compared to oil-hardening or alloy steels. **2. International Standard Cross-Reference** While JIS SK4 is the defining standard, it has direct equivalents in other major international standards systems. | Standard System | Equivalent Grade | Key Similarity | | :--- | :--- | :--- | | **JIS (Japan)** | **SK4** | Defining Standard | | **ASTM (USA)** | W1-1.0C / W108 | Similar high-carbon water-hardening grade | | **DIN (Germany)** | C100W1 / 1.1645 | Nearly identical carbon content | | **BS (UK)** | BW1B | Water-hardening tool steel type | | **ISO** | TC105 | ISO designation for similar composition | **3. Chemical Composition (Typical, weight %)** The composition is characterized by very high carbon content with minimal alloying, making it a truly "plain carbon" tool steel. | Element | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | | :--- | :--- | :--- | :--- | :--- | :--- | | **Content (%)** | 0.90 - 1.00 | ≤ 0.35 | ≤ 0.50 | ≤ 0.030 | ≤ 0.030 | *Note: Chromium (Cr) may be present in trace amounts (≤0.20%), but it is not an intentional alloying element.* **4. Physical & Mechanical Properties** * **Density:** Approximately 7.85 g/cm³ * **Thermal Conductivity:** Moderate. * **Machinability (Annealed State):** Fair. High carbon content makes it tougher to machine than low-carbon steels, but it is generally better than many alloy tool steels. * **Hardenability:** **Very Low (Shallow Hardening).** It achieves high hardness only to a limited depth from the quenched surface. The core remains softer and tougher. * **Quenching Medium:** **Water or Brine.** This aggressive quench is necessary to achieve full hardness but introduces higher risk of distortion and quench cracks, especially in parts with complex geometry or variable cross-sections. * **Typical Achievable Hardness:** * **Annealed State:** ~ 192 HB Max * **Hardened & Tempered State:** **Up to 64-66 HRC** (dependent on exact carbon content and heat treatment precision). **5. Heat Treatment** * **Forging:** Heat to 1050-850°C. Cool slowly in sand or furnace after forging. * **Annealing:** Heat to 750-780°C, slow furnace cool to ~550°C, then air cool. Results in a pearlitic structure ideal for machining. * **Hardening:** 1. **Preheat:** 650-700°C (critical to reduce thermal shock). 2. **Austenitizing:** 780-820°C. Soak time: ~20-30 minutes per inch of thickness. 3. **Quench:** Agitate vigorously in **water or brine (5-10% NaCl solution)** at room temperature. * **Tempering:** **Immediately** after quenching to relieve stresses. Typical tempering range is 150-200°C for 1-2 hours. Higher temperatures will reduce hardness significantly. **6. Product Applications** SK4 is suitable for tools that require an extremely hard, sharp cutting edge or wear-resistant surface, but are not subjected to high impact or elevated temperatures. * **Cutting Tools:** Simple hand tools like **chisels, plane blades, woodworking knives, and shear blades** for soft materials. * **Stamping & Forming Tools:** **Punches, dies, and blanking tools** for thin, soft metals (e.g., aluminum, brass), paper, leather, or plastic. * **Measuring & Gauging Tools:** **Low-wear gauge blocks, feeler gauges, and templates** where dimensional stability is key. * **Agricultural & Garden Tools:** **Pruner blades, sickle sections, and mower blades.** * **Miscellaneous Tools:** **Hardened washers, springs, and scrapers.** **7. Advantages & Limitations** | Advantages | Limitations | | :--- | :--- | | • Low cost and readily available.
• Capable of achieving very high surface hardness.
• Simple heat treatment process (does not require special furnaces).
• Easier to machine in annealed state than many tool steels. | • **Poor Hardenability:** Only surface hardens; not for thick sections.
• **High Distortion & Cracking Risk:** Due to severe water quenching.
• **Poor Toughness & Shock Resistance:** Brittle at full hardness.
• **Low Red (Hot) Hardness:** Hardness drops rapidly above 200°C; not for high-speed or hot work. | **Conclusion** JIS SK4 is a classic, economical water-hardening tool steel ideal for manufacturing simple, thin-section tools that demand a keen, wear-resistant edge in low-stress, room-temperature applications. Its successful use is highly dependent on skilled and careful heat treatment to manage its inherent quenching risks. For more complex shapes, thicker sections, or applications requiring better toughness, oil-hardening (e.g., JIS SKS series) or low-alloy steels (e.g., JIS SCM series) are recommended alternatives. -:- For detailed product information, please contact sales. -: JIS SK4 Water Hardening Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6790 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 SK4 Water Hardening Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SK4 Water Hardening Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SK4 Water Hardening Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of JIS SK4 Water Hardening 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 3261 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