Stainless Steel Grades and Applications: A Professional Buyer's Handbook for 2025
2026/07/03
1. Austenitic Stainless Steels (300 Series)
The 300 series represents approximately 70% of all stainless steel production worldwide.
| Grade | Composition | Key Properties | Applications |
|---|---|---|---|
| 304 / 304L | 18% Cr, 8% Ni | General corrosion resistance, weldability | Kitchen equipment, food processing |
| 316 / 316L | 16% Cr, 10% Ni, 2% Mo | Superior pitting resistance | Marine, chemical tanks, pharmaceutical |
| 321 | 17% Cr, 9% Ni, Ti stabilized | Intergranular corrosion resistance | Aircraft exhaust, high-temp processing |
| 310S | 25% Cr, 20% Ni | Oxidation resistance up to 1100°C | Furnace parts, heat exchangers |
304 remains the most traded grade due to balanced cost-performance. 316L demand grows at 6.2% CAGR driven by desalination and LNG infrastructure.
2. Ferritic and Martensitic Stainless Steels (400 Series)
- 430: Ferritic grade for automotive trim, dishwasher interiors, decorative applications.
- 410: Martensitic, heat-treatable. Used in cutlery, valve components, pump shafts.
- 440C: Highest carbon content for maximum hardness. Bearing assemblies, surgical instruments.
3. Duplex Stainless Steels
Duplex grades combine austenitic and ferritic microstructures, offering twice the yield strength of standard austenitic grades. Grade 2205 is specified for offshore platforms, chemical tankers, and desalination plants.
4. Procurement Checklist
- Verify Mill Test Certificates (MTC): Confirm composition and mechanical properties.
- Check Surface Finish: 2B, BA, No.4, HL, mirror finishes serve different applications.
- Confirm Dimensional Tolerances: Specify ASTM A480 or EN 10029.
- Value-Added Services: Laser cutting, bending, surface treatment reduce total project cost.
With global stainless steel trade exceeding 45 million metric tons annually, working with certified suppliers ensures competitive advantage.
