JIS SWRCH20K Carbon Steel Wire

JIS SWRCH20K Carbon Steel Wire Product Information -:- For detailed product information, please contact sales. -: JIS SWRCH20K Carbon Steel Wire Synonyms -:- For detailed product information, please contact sales. -:

JIS SWRCH20K Carbon Steel Product Information -:- For detailed product information, please contact sales. -: ## **Product Introduction: JIS SWRCH20K High-Quality Cold Heading Carbon Steel** **JIS SWRCH20K** is a **premium-quality cold forging/heading carbon steel** wire rod specified by the Japanese Industrial Standards (JIS) system. The designation follows the SWRCH series (**S**teel **W**ire Rod for **C**old **H**eading), with "20" indicating the nominal carbon content (0.20%) and the critical suffix **"K"** denoting **Special Quality with Guaranteed Hardenability**. This grade is engineered for demanding cold forming applications where components will undergo **subsequent carburizing or case-hardening heat treatment**. It combines the exceptional cold formability of the SWRCH series with tightly controlled chemistry that ensures predictable and consistent response to carburizing, resulting in a deep, hard wear-resistant surface and a tough, strong core. It is the material of choice for high-performance, safety-critical fasteners and mechanical parts. --- ### **1. Chemical Composition (JIS G 3507-1 Standard)** The composition is controlled with much stricter tolerances than the standard "A" grade, particularly regarding hardenability-influencing elements. Key specifications are as follows (in weight %): | Element | Carbon (C) | Silicon (Si) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Chromium (Cr)* | **Key Distinction from SWRCH20A** | | :------------- | :--------- | :----------- | :------------- | :------------- | :--------- | :------------- | :-------------------------------- | | **SWRCH20K** | 0.18-0.23 | 0.15-0.35 | **0.60-0.90** | **≤ 0.025** | **≤ 0.025** | ≤ 0.20 | Higher Si & Mn, Lower P & S, Guaranteed Hardenability. | | *SWRCH20A* | 0.18-0.23 | **≤ 0.10** | 0.30-0.60 | ≤ 0.030 | 0.040-0.070| - | Standard formability grade. | **Critical Features of the Composition:** * **Higher Manganese (Mn) and Controlled Silicon (Si):** These elements are essential for **hardenability**. The "K" grade has significantly higher and controlled ranges to ensure a guaranteed hardenability band, leading to consistent case depth and core strength after carburizing and quenching. * **Very Low Phosphorus (P) & Sulfur (S):** Impurity levels are minimized (**≤ 0.025%**) to maximize **core toughness, ductility, and fatigue strength**. This is critical for parts subjected to impact and cyclic loading. * **Hardenability Band:** Like the SxxCK series, SWRCH20K is supplied with a guaranteed hardenability range (e.g., JIS H-band), ensuring predictable heat treatment results across different production batches and part sections. --- ### **2. Physical & Mechanical Properties** Properties are evaluated in both the **supplied (spheroidize-annealed) condition** for forming and the **final case-hardened state**. **A. Supplied (Spheroidize Annealed) Condition:** * **Hardness:** **75 - 85 HRB** (Slightly higher than SWRCH20A due to higher Mn/Si, but still excellent for cold forming). * **Tensile Strength (σb):** ~ 420 - 520 MPa. * **Yield Strength (σ0.2):** ~ 310 - 380 MPa. * **Elongation (δ):** ≥ 30% (Maintains high ductility for cold forging). * **Microstructure:** Fine spheroidized cementite in ferrite, optimized for deformation and subsequent heat treatment response. **B. After Carburizing, Quenching & Tempering:** * **Surface (Case) Hardness:** **58 - 64 HRC** (High surface wear resistance). * **Core Hardness:** **28 - 42 HRC** (Provides strong mechanical support for the hard case, resistant to crushing). * **Core Tensile Strength:** Can achieve 900 - 1200 MPa range after proper heat treatment. * **Core Toughness:** Excellent impact and fatigue resistance due to low impurity levels and fine grain structure. --- ### **3. Product Applications** JIS SWRCH20K is specified for **high-strength, case-hardened components** manufactured via cold forging, where reliability and performance under stress are paramount. * **Automotive Safety & Drivetrain Components:** **High-strength flanged bolts, wheel studs, cylinder head bolts, gearbox shafts, synchronizer hubs, and differential pins.** * **High-Performance Fasteners:** **Property Class 10.9 and 12.9 bolts and screws** that require carburizing for added fatigue and wear resistance. * **Critical Mechanical Parts:** Cold-formed gears, cam lobes, bearing races, and injection pump components. * **Aerospace & Heavy-Duty Equipment:** Special bolts, pins, and linkage parts requiring the optimal combination of formability and final hardened properties. --- ### **4. International & Equivalent Standards** The "K" suffix aligns with international special-quality steels with guaranteed hardenability, particularly in cold heading wire forms. | Standard System | Equivalent / Comparable Grade | Condition / Remark | | :-------------- | :---------------------------- | :----------------- | | **JIS** | **SWRCH20K** | Primary standard (JIS G 3507-1). The "K" is key. | | **ASTM/AISI/SAE** | **10B21H** | The most direct functional equivalent. A boron-treated steel with similar carbon and guaranteed hardenability for cold heading and carburizing. | | **DIN (EN)** | EN 10263-4: **20MnB4** | European cold heading steel with boron for hardenability, designed for case hardening. | | **ISO** | ISO 4954: **Type CH20K** | Designation for cold heading steels with guaranteed hardenability. | | **GB (China)** | **ML20Cr** (or ML20BH) | Chinese cold heading ("ML") steel, often with chromium or boron for hardenability. | **Critical Distinction:** While standard cold heading grades (SWRCH20A, 1018, 1022) may have similar carbon content, **SWRCH20K is fundamentally different due to its hardenability guarantee.** For critical case-hardened components, specifying the "K" grade or its equivalents (like 10B21H/20MnB4) is mandatory to ensure part performance and safety. --- ### **5. Key Advantages & Considerations** **Advantages:** * **Optimal Property Combination:** Unites superior cold formability with excellent and predictable post-carburizing mechanical properties. * **Guaranteed Hardenability:** Ensures consistent case depth and core strength, vital for part-to-part uniformity in mass production. * **High Core Purity:** Low P and S content yield superior core toughness and fatigue life compared to standard cold heading grades. * **Production Efficiency:** Enables the high-volume manufacturing of complex, high-strength parts via cold forging with reliable final heat treatment. **Considerations:** * **Higher Cost:** Premium over standard SWRCH"A" grades due to tighter chemical controls and hardenability testing. * **Specific Application:** Over-specified for components not requiring case hardening. SWRCH20A is more cost-effective for through-hardened or non-heat-treated parts. * **Process Complexity:** Requires precise control of both cold forming and the subsequent carburizing/quenching/tempering processes to realize its full potential. --- **Disclaimer:** The information provided is for general reference and selection purposes. For engineering design, manufacturing, and heat treatment specification of critical components, always consult the official material data sheets from the steel producer and engage with qualified metallurgical and heat treatment engineers. Final part properties are highly dependent on the specific process parameters used. -:- For detailed product information, please contact sales. -: JIS SWRCH20K Carbon Steel Specification Dimensions Size： Diameter 20-1000 mm Length <5064 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 SWRCH20K Carbon Steel Properties -:- For detailed product information, please contact sales. -:

Applications of JIS SWRCH20K Carbon Steel Wire -:- For detailed product information, please contact sales. -: Chemical Identifiers JIS SWRCH20K Carbon Steel Wire -:- For detailed product information, please contact sales. -:

Packing of JIS SWRCH20K Carbon 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 1535 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