


13-8 stainless is a martensitic precipitation hardening stainless steel that has excellent strength, high hardness, superior toughness and good corrosion resistance. Good transverse toughness properties are achieved by tight chemical composition control, low carbon content, and vacuum melting. Typical applications are large airframe structural components and injection molding equipment.
13-8 Stainless
13-8 Round Bar
UNS S13800, Werkstoff 1.4548, EN 1.4548, AMS 5629, ASTM A 564
| Ni | Cr | Mo | C | P | S | Si | Mn | N | Al | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| MIN | 7.5 | 12.25 | 2.0 | - | - | - | - | - | - | 0.90 | - |
| MAX | 8.5 | 13.25 | 2.5 | 0.05 | 0.01 | 0.008 | 0.1 | 0.2 | 0.1 | 1.35 | Balance |
Density: 0.279 lb/inch3
Melting Range: 2560 - 2680°F
Electrical Resistivity: 613 Ohm-circ mil/ft
| Temperature, °F | 70 | 212 | 392 | 572 |
| Coefficient of Thermal Expansion, in/in°F x 10-6 | - | 7.2 | 7.5 | 7.8 |
| Thermal Conductivity Btu • ft/ft2 • hr • °F |
8.6 | 9.2 | 9.8 | 10.4 |
| Modulus of Elasticity, psi X 106 |
29.0 | 28.1 | 27.0 | 26.1 |
* 70°F to indicated temperature.
13-8 Stainless is available in the annealed condition, which is also called the solution heat treat condition or Condition A. Solution treat from 1675 - 1725°F for 15 to 30 minutes at temperature. Air cool or oil quench to below 60°F to effect complete transformation to martensite. Aging is normally carried out from 950 - 1150°F, depending on the desired final properties. Heat treatment is usually performed in air. Heat treatment of brazed components may be done in inert atmospheres. Reducing atmospheres should not be used because of the potential for nitrogen contamination.
| Condition | H950 | H1000 | H1025 | H1050 | H1100 | H1150 |
| Temperature, °F | 950±10 | 1000±10 | 1025±10 | 1050±10 | 1100±10 | 1150±10 |
| Time, hours | 4±0.25 | 4±0.25 | 4±0.25 | 4±0.25 | 4±0.25 | 4±0.25 |
Strength varies with heat treatment condition. The following table shows minimum mechanical properties for the various aged conditions, per AMS 5864.
| H950 | H1000 | H1025 | H1050 | H1100 | H1150 | |
| 0.2 Offset Yield Strength, ksi | 205 | 190 | 175 | 165 | 135 | 90 |
| Ultimate Tensile Strength, ksi | 220 | 205 | 185 | 175 | 150 | 135 |
| Elongation in 2", % | 10 | 10 | 11 | 12 | 14 | 14 |
| Reduction of Area, % (Longitudinal) | 45 | 50 | 50 | 50 | 50 | 50 |
| Reduction of Area, % (Transverse) | 45 | 50 | 50 | 50 | 50 | 50 |
| Reduction of Area, % (Short-Transverse) | 35 | 40 | 45 | 45 | 50 | 50 |
| Min Hardness, Rockwell | 45 | 43 | - | 40 | 34 | 30 |