JIS SK5M Water Hardening Tool Steel Sheet,Plate

JIS SK5M Water Hardening Tool Steel Sheet/Plate Product Information -:- For detailed product information, please contact sales. -: JIS SK5M Water Hardening Tool Steel Sheet/Plate Synonyms -:- For detailed product information, please contact sales. -:

JIS SK5M Water Hardening Tool Steel Product Information -:- For detailed product information, please contact sales. -: ### **Product Technical Datasheet: JIS SK5M Water-Hardening Tool Steel (Mo-Modified)** --- #### **1. Product Overview** **JIS SK5M** is a high-carbon, molybdenum-modified tool steel classified under Japanese Industrial Standard (JIS) G 4404. As a molybdenum-enhanced variant of the standard SK5, it represents an optimized member of the water-hardening family. The deliberate addition of molybdenum (Mo) significantly improves **hardenability** and **toughness** compared to conventional SK5, while retaining the core characteristic of achieving very high surface hardness through water quenching. SK5M offers a superior balance of properties, making it suitable for more demanding applications where the plain carbon SK5 grade may exhibit excessive brittleness or insufficient through-hardening. It remains a cost-effective solution that bridges the gap between plain carbon steels and more expensive alloy grades. --- #### **2. International Standard Cross-Reference** SK5M is defined under JIS G 4404, with functional equivalents in other systems based on composition and performance. | Standard System | Equivalent / Similar Grade | Note | | :--- | :--- | :--- | | **JIS G 4404 (Japan)** | **SK5M** | Defining standard (Molybdenum-type) | | **ASTM (USA)** | W2-0.9C (Mo variant) | Similar high-carbon water-hardening with Mo | | **DIN (Germany)** | 1.2003 / C90W2 | Similar composition and quenching method | | **BS (UK)** | **BW1C** | Water-hardening grade with Mo addition | | **ISO** | ~TC90 (Modified) | Similar application scope | | **GB (China)** | **T9Mo** | Modified high-carbon tool steel with Mo | --- #### **3. Chemical Composition (Typical, weight % per JIS G 4404)** The defining feature is the controlled addition of Molybdenum within the standard high-carbon framework. | Element | Carbon (C) | Silicon (Si) | Manganese (Mn) | **Molybdenum (Mo)** | Phosphorus (P) | Sulfur (S) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content (%)** | 0.80 - 0.90 | 0.10 - 0.30 | 0.30 - 0.60 | **0.10 - 0.25** | ≤ 0.030 | ≤ 0.030 | **Role of Key Alloying Elements:** * **Carbon (0.80-0.90%):** Provides high hardness and wear resistance after heat treatment. * **Molybdenum (0.10-0.25%):** The critical modifier. It increases hardenability (deepens the hardened zone), refines grain structure for improved toughness, and allows for slightly less severe quenching practices, reducing cracking tendency. --- #### **4. Physical & Mechanical Properties** * **Density:** ~7.85 g/cm³ * **Thermal Conductivity:** Moderate. * **Machinability (Annealed State):** Fair to Good. Comparable to SK5 when in a properly spheroidized annealed condition. * **Hardenability:** **Low to Moderate (Improved over SK5).** The Mo addition provides a measurably deeper and more uniform hardened zone than plain SK5, especially in sections up to ~20mm. * **Primary Quenching Medium:** **Water or Brine.** The presence of Mo provides a wider processing window, sometimes allowing the use of agitated warm water or brine for less severe quenching. * **Typical Achievable Hardness:** * **Annealed State:** ~ 187 - 212 HB * **Hardened & Tempered State:** **61 - 64 HRC** (Can reach the upper range with optimal processing). --- #### **5. Heat Treatment Guidelines** * **Forging:** Heat uniformly to 1050-850°C. Cool slowly in furnace or insulating medium. * **Annealing:** Heat to 750-780°C, slow furnace cool to ~500°C, then air cool. Aim for a spheroidized structure. * **Hardening:** 1. **Preheat:** Mandatory at 650-700°C. 2. **Austenitizing:** **790-820°C.** The Mo addition permits a slightly higher austenitizing temperature than plain SK5 for better alloy solutioning. 3. **Quench:** Agitate in **water, brine, or a fast polymer quenchant.** The improved hardenability may allow for slightly slower agitation in some cases. * **Tempering:** **Perform immediately** after quenching. Temper at **150-200°C for 1-2 hours.** For applications requiring better toughness at the expense of some hardness, tempering at 250-300°C can be considered (resulting hardness ~55-59 HRC). --- #### **6. Product Applications** SK5M is used for applications similar to SK5 but where enhanced performance, reliability, or suitability for slightly thicker sections is required. * **Cutting Tools:** **Heavier-duty hand saw blades (for metal cutting), band saw blades for wood, industrial knives** for cutting textiles, rubber, and plastics. * **Forming & Stamping Tools:** **Punches, dies, and forming tools** for mild steel and non-ferrous metals where higher toughness than SK5 is needed. * **Hand Tools:** **High-quality cold chisels, masonry nails, screwdriver tips, and pincer jaws.** * **Agricultural & Forestry Tools:** **Chipper blades, heavier-duty pruning saws, and cultivator teeth.** * **Wear Parts:** **Guide plates, wear strips, and machine parts** subject to abrasion but requiring some resistance to chipping. * **Blades:** **Circular cutter blades for packaging and food processing.** --- #### **7. Advantages & Limitations** | Advantages | Limitations | | :--- | :--- | | • **Improved hardenability and depth of hardness** over SK5.
• **Better toughness and shock resistance** due to finer grain structure from Mo.
• **Reduced risk of quenching cracks** compared to plain SK5 for equivalent sections.
• **Cost-effective** performance upgrade from SK5 without moving to full alloy steels.
• **Maintains very high achievable hardness.** | • **Still requires water quenching** with associated distortion risks for complex shapes.
• **Not suitable for deep hardening** like oil-hardening or air-hardening steels.
• **Low hot hardness;** unsuitable for high-speed or hot work.
• **Limited dimensional stability** during heat treatment compared to oil-hardening grades. | --- #### **8. Selection Guide: SK5 vs. SK5M vs. Oil-Hardening** * **SK5 vs. SK5M:** Choose **SK5M** when you need **more consistent through-hardening, better toughness, or are heat treating slightly thicker/more complex parts.** SK5 is sufficient for very simple, thin-section tools where cost is the absolute primary driver. * **SK5M vs. Oil-Hardening (e.g., SKS93):** Choose **SK5M** if **ultimate surface hardness (>62 HRC) is critical** and part geometry is simple. Choose an **oil-hardening steel** when **minimal distortion, better dimensional control, or deeper hardening in complex shapes** is required, even if peak hardness is slightly lower (60-62 HRC). **Conclusion:** JIS SK5M is a **technologically enhanced evolution of traditional water-hardening steel.** The strategic addition of molybdenum successfully addresses key weaknesses of plain carbon grades—improving toughness, hardenability, and processing safety—while preserving their signature high hardness and low cost. It is the **recommended choice over SK5 for most professional and industrial tool applications** where water hardening is specified, providing a more reliable and higher-performance outcome with only a marginal cost increase. -:- For detailed product information, please contact sales. -: JIS SK5M Water Hardening Tool Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6793 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 SK5M Water Hardening Tool Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SK5M Water Hardening Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SK5M Water Hardening Tool Steel Sheet,Plate -:- For detailed product information, please contact sales. -:

Packing of JIS SK5M 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 3264 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