1. Overview
AISI 420 stainless steel, also known as 3Cr13 or SUS420J2, is a martensitic stainless steel containing about 13% chromium.
It offers an excellent combination of hardness, wear resistance, and corrosion resistance after appropriate heat treatment, making it a preferred material for cutting tools, blades, and mechanical wear parts.
Jiaxiao MTC manufactures AISI 420 stainless steel strips in cold rolled annealed and hardened & tempered conditions, with polished or bright finishes to meet the highest precision standards.
2. Chemical Composition and Equivalent Grades
| Standard | Equivalent Grades | C (%) | Mn (%) | Si (%) | Cr (%) | Ni (%) | P max | S max |
|---|---|---|---|---|---|---|---|---|
| DIN | 3Cr13 | 0.25–0.35 | ≤1.50 | ≤1.00 | 12.0–14.0 | — | ≤0.035 | ≤0.035 |
| AISI | 420 | — | — | — | — | — | — | — |
| JIS | SUS420J2 | — | — | — | — | — | — | — |
The relatively high chromium content provides good corrosion resistance, while the moderate carbon level ensures the ability to achieve high hardness (up to 50–52 HRC) after quenching and tempering.
3. Manufacturing and Processing
Jiaxiao MTC employs a full range of processing steps to ensure the highest quality surface finish and dimensional accuracy:
- Raw Material Selection:
Only ISO-certified hot rolled coils are used as the starting material. - Acid Pickling:
Removes oxides and surface impurities for uniform rolling. - Cold Rolling:
Reduces thickness with precise tolerance control. - Annealing:
Conducted in a controlled atmosphere to prevent decarburization and achieve a bright surface. - Hardening and Tempering:
- Hardening temperature: 980–1050°C
- Tempering temperature: 150–370°C
- Results in high hardness with retained corrosion resistance.
- Surface Finishing and Edge Treatment:
Available finishes include bright, polished, or mirror, and edges can be slit, rounded, or square.
4. Mechanical Properties
| Condition | Hardness | Tensile Strength | Surface Finish | Edge Type |
|---|---|---|---|---|
| Annealed | ≤200 HV | 600–800 N/mm² | Bright / Mirror | Slit / Mill |
| Hardened & Tempered | 40–52 HRC | 1300–1600 N/mm² | Polished / Bright | Rounded / Square |
Thickness Range: 0.1–5.0 mm
Width Range: up to 500 mm
5. Key Characteristics
- Corrosion Resistance:
Excellent in dry air, freshwater, mild acids, and alkalis. - Hardness and Wear Resistance:
High hardness achievable after quenching; ideal for cutting edges and mechanical wear parts. - Polishability:
Smooth, bright, and mirror surface finish possible for decorative or precision applications. - Machinability:
Good machinability in annealed condition; easy to harden for final performance. - Dimensional Accuracy:
Maintained through precision cold rolling and levelling.
6. Typical Applications
AISI 420 stainless steel strip is widely used across various industries that require both mechanical strength and surface durability:
- Cutting Tools & Blades:
Knife blades, trowel blades, scrapers, putty knives, and scissors. - Industrial Components:
Wear-resistant spacers, shims, washers, and clips. - Automotive Applications:
Seatbelt parts, clutch discs, and decorative trims. - Shoe Hardware & Accessories:
Toe caps, shoe shanks, and insole supports.
7. Quality Control and Standards
Jiaxiao MTC follows strict quality assurance procedures throughout production:
- Chemical Composition Testing — confirmed via spectrometer.
- Hardness Testing — Vickers, Rockwell, and Brinell methods.
- Flatness and Straightness — controlled within tolerance classes R1–R4.
- Surface Inspection — mirror and polished surfaces free from oxidation or pitting.
Thickness tolerance: ±0.015–0.070 mm
Width tolerance: ±0.20–0.80 mm
8. Packaging and Delivery
Each coil is:
- Lightly oiled to prevent corrosion,
- Wrapped in plastic film and anti-rust paper,
- Packed in wooden pallets or steel frames for export,
ensuring safe arrival in perfect condition.
9. About Jiaxiao MTC
Guangzhou Jiaxiao Material Technology Co., Ltd.
specializes in high carbon steel, alloy steel, and stainless steel strips for global industrial use.
With advanced rolling, annealing, and polishing facilities covering 25,000 m² and over 100 skilled staff, Jiaxiao MTC provides reliable, high-quality steel materials for manufacturers in the tooling, automotive, and hardware sectors.
Annual production capacity exceeds 15,000 tons.
