Provided is a steel pipe or tube for hydrogen gas that has both excellent hydrogen embrittlement resistance and high productivity and can be used very suitably as parts of pressure vessels for hydrogen gas. The steel pipe or tube for hydrogen gas having a finish-polished inner surface, in which the inclination angle of a polishing trace present on the inner surface with respect to a circumferential direction of the steel pipe or tube for hydrogen gas is 0 to 30.

A fluid container (10) for fluid containment. The internal surface of the container body (12) defines a fluid-containment chamber (14), which has at least one fluid inlet and/or outlet port (18). Associated with at least one fluid inlet and/or outlet port (18), there is a fluid-flow control device, having a control body (16) integrally formed with the container body (12) as one piece.

The present invention is a fluorohydrocarbon compound-filled gas container obtained by filling a gas container with a fluorohydrocarbon compound, the gas container being made of manganese steel, an amount of aluminum adhering to an inner surface of the gas container as measured by XPS analysis being 1 mol % or less, and the fluorohydrocarbon compound being a compound represented by C.sub.4H.sub.9F or C.sub.5H.sub.11F. The present invention provides a fluorohydrocarbon compound-filled gas container that is obtained by filling a gas container with a fluorohydrocarbon compound represented by C.sub.4H.sub.9F or C.sub.5H.sub.11F, and suppresses or reduces a decrease in the purity of the fluorohydrocarbon compound with which the gas container is filled.