🟦 Product Overview
420 Stainless Steel Bar is a high‑carbon martensitic stainless steel known for:
- High hardness after heat treatment
- Excellent wear resistance
- Good corrosion resistance
- Magnetic properties
- High polishability
420 is widely used for:
- Cutting tools
- Surgical instruments
- Knives & blades
- Molds & dies
- Mechanical parts requiring high hardness
Compared with 410:
- Higher carbon content → higher hardness
- Better wear resistance
- Suitable for cutting and tooling applications
420 can be hardened to 50–55 HRC, making it one of the hardest stainless steels in the martensitic family.
🟦 Standards
- ASTM A276
- ASTM A479
- EN 10088
- JIS G4303 SUS420J1 / SUS420J2
- GB/T 1220 20Cr13
🟦 Grade Included
- 420 Stainless Steel (UNS S42000 / 1.4021 / 1.4028)
🟦 Product Specifications & Available Sizes
Shapes Available
- Round Bar
- Square Bar
- Hex Bar
- Flat Bar
Diameter Range
Length
Surface Conditions
- Hot Rolled
- Cold Drawn
- Peeled / Turned
- Polished
- Quenched & Tempered (Q+T)
🟦 Chemical Composition（420）
| Element | Content (%) |
|---|
| C | 0.26–0.40 |
| Mn | ≤ 1.00 |
| Si | ≤ 1.00 |
| P | ≤ 0.040 |
| S | ≤ 0.030 |
| Cr | 12.0–14.0 |
📌 Higher carbon = higher hardness after heat treatment.
🟦 Mechanical Properties（Annealed Condition）
| Property | Requirement |
|---|
| Tensile Strength | 650–850 MPa |
| Yield Strength | ≥ 345 MPa |
| Elongation | ≥ 15% |
| Hardness | ≤ 217 HB |
🟦 Mechanical Properties（After Q+T Heat Treatment）
| Property | Requirement |
|---|
| Tensile Strength | 900–1200 MPa |
| Yield Strength | 600–800 MPa |
| Hardness | 48–55 HRC |
📌 420 is ideal for blades, tools, and wear‑resistant parts.
🟦 Physical Properties
| Property | Value |
|---|
| Density | 7.75 g/cm³ |
| Magnetic | Yes |
| Thermal Conductivity | 24 W/m·K |
| Corrosion Resistance | Moderate–Good |
🟦 Manufacturing Processes
- Hot Rolling
- Cold Drawing
- Turning / Peeling
- Grinding / Polishing
- Quenching & Tempering
- Straightening
- Ultrasonic Testing
🟦 Primary Industry Usage
- Cutting tools & knives
- Surgical instruments
- Molds & dies
- Pump shafts & valve parts
- Wear‑resistant mechanical components
- Industrial blades
- Measuring tools
🟦 Why Use 420 Stainless Steel Bar
- High hardness (up to 55 HRC)
- Excellent wear resistance
- Good corrosion resistance
- Magnetic martensitic structure
- Ideal for cutting and tooling applications
🟦 Why Choose WelSteels
- Full size range of 420 stainless bars
- Hot rolled, cold drawn, polished, and Q+T options
- MTC 3.1 + third‑party inspection
- Export‑grade packaging
- Competitive pricing for global buyers
