SUS430 vs SUS420 stainless steel: Hardness
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When choosing the right stainless steel for specific applications, understanding the hardness of various grades is crucial. For many industries, SUS430 and SUS420 are two popular grades of stainless steel, each with distinct characteristics. In this article, we'll dive into a key property-hardness-to help you make an informed decision.
What is SUS430 stainless steel?
SUS430 is a popular, low-cost ferritic stainless steel known for its good corrosion resistance, excellent formability, and magnetic properties, making it ideal for household appliances (sinks, dishwasher linings), automotive trim, and architectural detailing where high strength isn't critical, though it's less corrosion-resistant than austenitic grades like 304 in harsh environments.
What Is SUS420 Stainless Steel?
SUS420 is a Japanese standard designation for a high-carbon, martensitic stainless steel that offers excellent hardness, wear resistance, and good corrosion resistance, especially after heat treatment and polishing, making it ideal for knives, surgical tools, molds, and pump parts. It's a heat-treatable alloy, magnetic, and achieves its best properties (strength, hardness, corrosion resistance) when fully hardened, unlike softer austenitic grades.
SUS430 vs SUS420:Chemical Composition
| Property | SUS430 | SUS420 |
|---|---|---|
| Chemical Composition | ||
| Carbon (C) | ≤0.12% | 0.15 - 0.40% |
| Chromium (Cr) | 16.0 - 18.0% | 12.0 - 14.0% |
| Nickel (Ni) | ≤0.75% | ≤0.60% |
| Manganese (Mn) | ≤1.0% | ≤1.0% |
| Silicon (Si) | ≤1.0% | ≤1.0% |
| Phosphorus (P) | ≤0.04% | ≤0.04% |
| Sulfur (S) | ≤0.03% | ≤0.03% |
SUS430 vs SUS420：Mechanical Properties
| Mechanical Properties | SUS430 | SUS420 |
| Yield Strength (MPa) | 205 - 275 MPa | 450 - 650 MPa |
| Tensile Strength (MPa) | 480 - 650 MPa | 700 - 900 MPa |
| Elongation (%) | ≥15% | ≥12% |
| Density (g/cm³) | 7.75 - 7.85 g/cm³ | 7.75 - 7.85 g/cm³ |
| Modulus of Elasticity (GPa) | 200 - 210 GPa | 200 - 210 GPa |
SUS430 vs SUS420: Hardness Comparison
| Property | SUS430 | SUS420 |
|---|---|---|
| Hardness (Brinell) | 170 HB | 300 HB (depending on heat treatment) |
| Hardness (Rockwell B) | 90-95 HRB | N/A |
| Hardness (Rockwell C) | N/A | Up to 50 HRC |
SUS430 vs. SUS420 Stainless Steel: Corrosion Resistance
SUS430 generally offers better overall corrosion resistance than SUS420 in mild conditions, thanks to its higher chromium content (around 17%), while SUS420's corrosion resistance improves significantly after hardening but is lower than 430 when annealed, making 430 a more cost-effective choice for general applications like appliance trim, but 420 is excellent for blades (cutlery) needing hardness.
SUS430 vs. SUS420 Stainless Steel: Applications
SUS430 (ferritic) offers excellent formability and good corrosion resistance for decorative/indoor uses like appliances, automotive trim, and architectural elements, while SUS420 (martensitic) is known for hardness and edge retention, making it ideal for cutlery (knives, scissors) and tools where it can be hardened, though its corrosion resistance is lower than 430, especially when annealed.
If you have project requirements for SUS430 or SUS420 stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. These materials can be processed into various practical product forms, including plates, coils, tubes, bars, and wires. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.
