MIL-T-8973, MILITARY SPECIFICATION: TUBING, STEEL, CORROSION AND HEAT RESISTANT, FOR AEROSPACE VEHICLE HYDRAULIC SYSTEMS ASSEMBLED BY BRAZING (12 SEP 1969) [S/S BY SAE-AMS5897]., This specification covers thin wall close-tolerance 1/8 hard tubing to 1-5/8 inches outside diameter suitable for use in high-pressure hydraulic or pneumatic systems assembled with brazed joints.