MIL-S-22664B, MILITARY SPECIFICATION: STEEL, STRUCTURAL SHAPES ALLOY, HIGH YIELD STRENGTH (HY-80 AND HY-100) (15 MAR 1988) [S/S BY T9074-BD-GIB-010/300]., This specification covers HY-80 and HY-100 alloy steel rolled and extruded shapes for use in applications where good weldability and notch toughness are required.