This International Standard specifies the essential dimensional characteristics and material requirements for metallic pipes, tapped holes and male fittings used in pneumatic braking systems in road vehicles using compressed air at a pressure under 2 MPa (20 bar).
SIS SS-ISO 4039:1979 history
1979SIS SS-ISO 4039:1979 Road vehicles — Pneumatic braking systems — Pipes, tapped holes and male fittings