MIL-T-6845D, MILITARY SPECIFICATION: TUBING, STEEL, CORROSION-RESISTANT (S30400), AEROSPACE VEHICLE HYDRAULIC SYSTEM 1/8 HARD CONDITION (26 APR 1985) [S/S BY SAE-AMS-T-6845]., This specification presents requirements for thin-walled (inside diameter greater than four times the wall thickness and outside diameter 1/4 inch and larger) corrosion-resistant steel tubing in approximately the 1/8 hard condition, of special quality, suitable for use in high-pressure hydraulic systems