Composition: The 15-5 PH Stainless Steel is composed according to ASTM A564-06 standards. Key elements include Carbon (0.07% max), Silicon (1.0% max), Manganese (1.0% max), Phosphorous (0.04% max), Sulfur (0.03% max), Chromium (14.0-15.5%), Nickel (3.5-5.5%), Copper (2.5-4.5%), Niobium + Tantalum (0.15-0.45%), with the balance being Iron.

Mechanical Properties: The mechanical properties were tested in independent laboratories. The properties for 'As Sintered H900' and 'Wrought H900' conditions are provided. For 'As Sintered H900', the Ultimate Tensile Strength is 1281 MPa, 0.2% Yield Strength is 808 MPa, Elongation at Break is 9.5%, Hardness is 38.72 HRC, and Relative Density is 99.5%. For 'Wrought H900', the Ultimate Tensile Strength is 1310 MPa, 0.2% Yield Strength is 1170 MPa, Elongation at Break is 10%, Hardness is 40 HRC, and Relative Density is 100%.

Standards and Testing: The testing standards referenced include ASTM A564 for mechanical properties, ASTM E8 for tensile testing, ASTM E18 for hardness testing, and ASTM B962 for density measurement.