420F vs 420J2 Stainless Steel: Machinist's Guide to Choosing Right
When stainless steel is required for precision machining but budgets are limited, 420F and 420J2 stainless steels are the preferred choices.
These two martensitic stainless steel grades, 420F and 420J2, serve very different purposes.
Core Differences
| Property | 420J2 (3Cr13) | 420F |
| Machinability | Moderate | Excellent |
| Edge Retention | Superior | Good |
| Corrosion Resistance | Better | Slightly Reduced |
| Best For | Cutting Tools & Valves | High-Volume Fasteners |
Composition Breakdown
Composition Analysis
420J2 Stainless Steel:
Chromium: 12-14%
Carbon: 0.26-0.40%
Sulfur: ≤0.030%
Key Characteristics:
420F Stainless Steel:
Added Sulfur (≥0.15%)
Added Phosphorus (≤0.060%)
Key Characteristics: Free-cutting Chip Formation
Performance Comparison
Machining Characteristics
420J2 Stainless Steel:
Requires lower machining speeds
Requires sharp carbide tools
Produces continuous chips
420F Stainless Steel:
Machining speeds increased by 30%
Can be used with high-speed steel tools
Produces clean chip breakage
Heat Treatment
| Process | 420J2 | 420F |
| Hardening Temp | 980-1030°C | 950-1010°C |
| Tempering | 200-300°C | 150-250°C |
| Max Hardness | HRC 52 | HRC 50 |
Welding Considerations
Both grades of stainless steel require the following:
1. Preheat to 250-300°C;
2. Post-weld annealing is mandatory.
Applications of 420F and 420J2 Stainless Steel:
Main Applications of 420J2:
Surgical scalpels; valve seats and stems; bearing components; fuel injectors; applications requiring edge retention and moderate corrosion resistance
Best Applications of 420F:
CNC machining of bolts; electrical connectors; automotive parts; applications requiring machining speeds exceeding the hardness limit
How customers determine which stainless steel grade to choose:
420J2:
Cutting edges must remain sharp; welding is not required; budget allows for slower machining speeds.
420F:
High-volume CNC machining; chip control is critical; parts are complex and require multiple operations; tooling costs need to be minimized.
Tabs:stainless steel coil ,304 ss coil
Recent Posts
Have Any Question?
High-quality manufacturers in the stainless steel industry, feel free to ask
