American Wide Flange Beams . American wide flange beams are available in eight ASTM standards including A36, A572-Grade 50, A588, A690, A709, A913-Grade 50, A913-Grade 65, and A992. The A36 standard has yield strength of 36 ksi and the A572, A588, A690, A709, A913 and A992 have a yield strength of 50 ksi. A913 has a yield strength of 65 ksi.ASTM Structural Steel Standards Infra-Metals Co.Its multiple favorable properties make it a staple for construction applications. Strength, Weldability, and Machinability. One of the most commonly used A572 grades is A572-50. This grade has an ultimate tensile strength of 65,300 psi and a high tensile yield strength of 50,000 psi.