✅ General Technical Characteristics
Stainless steel AISI 303 (EN 1.4305) is an austenitic corrosion-resistant steel with an increased sulfur content, which significantly improves its machinability. This alloy demonstrates excellent mechanical properties, good corrosion resistance, and high wear resistance. Due to its characteristics, AISI 303 is widely used in the production of precision-machined components.
Main Characteristics:
- Improved machinability due to increased sulfur content.
- Good corrosion resistance in mildly aggressive environments.
- High mechanical strength and wear resistance.
- Good weldability with some limitations (due to sulfur content).
- Suitable for automated machining processes.
🔬 Chemical Composition AISI 303 / EN 1.4305 (%)
- Carbon (C): ≤ 0.10
- Silicon (Si): ≤ 1.0
- Manganese (Mn): ≤ 2.0
- Phosphorus (P): ≤ 0.045
- Sulfur (S): 0.15 – 0.35
- Chromium (Cr): 17.0 – 19.0
- Nickel (Ni): 8.0 – 10.0
💡 The addition of sulfur significantly improves machinability but may reduce corrosion resistance compared to AISI 304.
🏭 Applications
Steel AISI 303 (EN 1.4305) is in high demand in industries requiring high precision machining and good wear resistance.
Main Application Areas:
- Production of precision components and fasteners.
- Automated machining processes (turning, milling operations).
- Mechanical engineering and bearing manufacturing.
- Electrical industry.
- Production of shafts, screws, nuts, and other structural components.
📊 Mechanical Properties
- Tensile Strength (Rm): 500 – 750 MPa
- Yield Strength (Rp0.2): ≥ 190 MPa
- Hardness (HB): ≤ 230 HB
- Elongation (A5): ≥ 35 %
⭐ Features
- High machinability – allows efficient processing on machine tools.
- Good mechanical strength – withstands significant loads.
- Limited corrosion resistance – lower than AISI 304, but suitable for dry environments and moderate conditions.
- High wear resistance – makes the material suitable for mechanical components.
- Limited weldability – hot cracking may occur due to sulfur content.
AISI 303 / EN 1.4305 steel delivery forms
| Circle AISI 303 / EN 1.4305 | Diameter: 6 – 500mm |
| Sheet AISI 303 / EN 1.4305 | Thickness: 0.5 – 100mm |
| Pipe AISI 303 / EN 1.4305 | – Hot rolled round pipe with a diameter of 38 to 244, 5 mm, thickness from 3 to 25 mm -Cold drawn round pipe diameter from 6 to 219.1mm thickness from 0.9 to 14.2mm |
| Hex AISI 303 / EN 1.4305 | Diameter: 17-65mm |
| AISI 303 / EN 1.4305 strip | Thickness: 5-50mm ; Width: 50-250mm |
| Square AISI 303 / EN 1.4305 | Size: 10- 80mm |




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