MIL-STD-1688A, MILITARY STANDARD: FABRICATION, WELDING AND INSPECTION OF HY-80/100 SUBMARINE APPLICATIONS (15 DEC 1990)., This standard contains minimum requirements for shipbuilding practices, standards for materials, weld joint design, welding inspection, and record requirements for combatant submarines and non-combatant submersibles constructed of HY-80/100 materials. Requirements for HY-180 submarine applications are contained in MIL-STD-1681. Requirements for non-HY steel submarine applications are contained in MIL-STD-1689.