JIS G4305 SUS 420J1 Cold Rolled Stainless Steel Coil Supplier

420J1 Cold Rolled Stainless Steel Coil & Sheet | JIS G4305 420J1 Stainless Steel Strip Manufacturer & Exporter – Gangsteel

Gangsteel is a premier manufacturer and global exporter of premium JIS G4305 420J1 cold rolled stainless steel coils, sheets, and strips. As a high-carbon martensitic grade (commonly referred to as 420J1 or SUS420J1), 420J1 delivers excellent hardenability, superior wear resistance, high hardness after heat treatment, and moderate corrosion resistance. With carbon content of 0.16–0.25% and chromium 12.0–14.0%, it is specifically engineered for applications requiring sharp edges, abrasion resistance, and good cutting performance while maintaining basic rust resistance in mild environments.

Our precision cold rolling facilities produce 420J1 in the annealed condition with superior surface finishes (2B, BA, No.4, HL), tight tolerances (±0.02 mm), and consistent properties fully compliant with JIS G4305 (Cold-rolled stainless steel plate, sheet and strip). Equivalent to ASTM A240 Type 420, EN 1.4021 (X20Cr13), and GB 20Cr13 or similar, Gangsteel's 420J1 products serve industries worldwide including cutlery, knives, scissors, surgical instruments, tools, turbine blades, and high-wear mechanical components.

This comprehensive product introduction details every aspect of our JIS G4305 420J1 cold rolled stainless steel — from composition and properties (in tables) to manufacturing, applications, advantages, and why Gangsteel is your trusted partner for reliable, hardenable martensitic supply.

Introduction to 420J1 Stainless Steel

420J1 is a martensitic chromium stainless steel with higher carbon content than standard 410, enabling superior hardness (up to 50–55 HRC after proper quenching and tempering) and exceptional wear/abrasion resistance. It balances moderate corrosion resistance with the ability to achieve razor-sharp edges, making it the preferred choice for blades and cutting tools. Unlike fully austenitic grades, 420J1 is magnetic in all conditions and can be heat treated to tailor strength and toughness.

Gangsteel specializes in cold rolled 420J1, supplying material in soft annealed condition for optimal forming and machining, with full heat treatment guidance for final hardening. It offers better edge retention than 410 while remaining more economical than premium tool steels.

Chemical Composition of JIS G4305 420J1

Chemical Composition Table

Gangsteel's production maintains optimal carbon and chromium ranges for maximum hardness and edge performance. Full chemical analysis and EN 10204 3.1 certificates are standard.

Mechanical Properties

In annealed condition per JIS G4305:

Mechanical Properties Table (Annealed)

Hardened and Tempered(typical after heat treatment):

• Quenched and tempered at 150–370°C: Rm 1100–1500+ MPa, Hardness 48–55 HRC
• Higher tempering temperatures: Improved toughness with reduced hardness

420J1 achieves significantly higher hardness than 410 due to elevated carbon content.

Physical Properties

Physical Properties Table

These properties provide excellent thermal conductivity and dimensional stability after hardening.

Equivalent Materials Comparison

Equivalent Materials Comparison Table

420J1 offers higher hardness potential than 410 while remaining cost-effective for cutting tools.

Manufacturing Process: Cold Rolled at Gangsteel

Gangsteel's process: hot rolling to intermediate thickness, annealing/pickling, multi-pass cold reduction in precision mills, final annealing/skin pass for annealed condition, slitting/edge trimming. Thickness: 0.3–3.0 mm (coils/sheets). Width: 600–1524 mm. In-line controls ensure tight tolerances and superior surfaces.

Finishes: 2B (standard matte), BA (bright annealed), No.4/HL (brushed). Protective films and custom slitting available. Material supplied annealed for optimal forming and machining.

Available Forms, Sizes, and Specifications

• Cold rolled coils: 0.3–3.0 mm thick, up to 1524 mm wide
• Cold rolled sheets: Cut-to-length up to 6000 mm
• Strips: Narrow from 10 mm

Compliant with JIS G4305; optional ASTM A240/EN cross-certification. Tolerances per JIS or tighter.

Key Applications of 420J1 Cold Rolled Products

420J1 excels in high-wear, edge-retention applications:

Cutlery and Kitchen Tools

• Knife blades, scissors, kitchen knives
• Surgical instruments, razor blades

Industrial Tools and Components

• Turbine blades, pump parts, valve seats
• Wear-resistant machine components

Automotive and Aerospace

• Fasteners, exhaust parts requiring hardness
• Precision cutting tools

Other Uses

• Mining equipment, agricultural blades
• Mold components, high-abrasion parts

Its hardenability makes it ideal for sharp, durable edges.

Advantages of Choosing 420J1 Stainless Steel

• Achieves high hardness (48–55 HRC) after heat treatment
• Excellent wear and abrasion resistance
• Good edge retention for cutting tools
• Moderate corrosion resistance in mild environments
• Cost-effective martensitic grade vs. tool steels
• Magnetic; good machinability annealed
• Superior to 410 for blade applications

Corrosion and Oxidation Resistance

Moderate resistance to atmospheric corrosion, fresh water, steam, and mild acids; lower in chlorides/acids than austenitics. Oxidation resistance up to ~650–700°C continuous; suitable for hot dry atmospheres.

Weldability and Fabrication

Fair to poor weldability; pre-heat (150–300°C) and post-weld tempering recommended to avoid cracking. Use matching fillers (ER420). Annealed state allows excellent forming and machining; full hardening applied after fabrication.

Why Choose Gangsteel for 420J1 Cold Rolled Coils and Sheets?

• Precision cold rolling with advanced mills
• Strict JIS G4305 compliance and traceability
• Diverse finishes/stock for fast delivery
• Competitive pricing, flexible MOQ
• Export to 60+ countries with seaworthy packaging
• Technical support: heat treatment/hardening advice, specs
• ISO 9001 certified; third-party inspections (SGS/BV/TUV)

Quality Assurance and Certifications

Batch testing: chemical, mechanical, surface, dimensional. MTRs with heat traceability. Audits welcomed.

Packaging, Shipping, and Logistics

Coils eye-to-sky/wall on pallets, waterproof/edge-protected. Sheets skidded. Container/bulk with tracking/insurance.

Conclusion: Partner with Gangsteel for High-Hardness 420J1 Solutions

420J1 Cold Rolled Stainless Steel Coil & Sheetfrom Gangsteel, produced to JIS G4305, delivers outstanding hardenability, wear resistance, and edge performance for cutting and tool applications. As a dedicated manufacturer and exporter, we ensure consistent quality and dedicated service worldwide.

Contact Gangsteel today for competitive quotes, samples, technical data sheets, or custom 420J1 cold rolled stainless steel coils, sheets, and strips. Trust us for premium high-carbon martensitic stainless solutions.