Question: what is fy 50 ksi?
Answer: The industry's technical institute describes the standard thus: "ASTM A992 (Fy = 50 ksi, Fu = 65 ksi) is the preferred material specification for wide-flange shapes, having replaced ASTM A36 and A572 grade 50. ... Material ductility is well defined since a maximum yield-to-tensile strength ratio of 0.85 is specified.