Stainless Steel 321 has similar composition to 304 Stainless Steels but with addition of Titanium.
Stainless Steel 321 is also known as AISI 321, Nirosta 4541, Polarit 731, and Remanit 4541.
| Element | Min % | Max % |
| C | – | 0.08 |
| Mn | – | 2.00 |
| P | – | 0.04 |
| S | – | 0.03 |
| Si | 0.40 | 1.00 |
| Cr | 17.00 | 19.00 |
| Ni | 9.50 | 12.00 |
| N | – | 0.10 |
| Mo | – | 0.50 |
| Ti | 5 x C | 0.70 |
| Fe | BAL | |
Density
8.03 g/cm³ | 0.29 lb/in³
Melting Point
1370°C | 2500°F
Coefficient of Expansion
16.6 μm/m °C (20 – 100°C) | 9.2 x 10-6 in/in °F (70 – 212°F)
Modulus of Elasticity
193 kN/mm² | 28000 ksi
Modulus of Rigidity
78 kN/mm² | 11300 ksi
Heat Treatment of Finished Parts
| Condition as supplied by Alloy Wire | Type | Temperature | Time (Hr) | Cooling | |
| °C | °F | ||||
| Annealed or Spring Temper | Stress Relieve | 450 | 840 | 1 | Air |
Properties
| Condition | Approx. tensile strength | Approx. operating temperature | ||
| N/mm² | ksi | °C | °F | |
| Annealed | 600 – 800 | 87 – 116 | -200 to +300 | -330 to +570 |
| Spring Temper | 1300 – 2200 | 189 – 319 | -200 to +300 | -330 to +570 |