This part of ISO 12151 specifies the general and dimensional requirements for the design and performance of hose fittings with O-ring face seal ends in accordance with ISO 8434-3, made of carbon steel, for nominal hose inside diameters of 6,3 mm to 38 mm, inclusive, in accordance with ISO 4397.NOTE 1 Materials other than carbon steel can be supplied as agreed between the manufacturer and user. NOTE 2 For hose fittings used in hydraulic and pneumatic braking systems on road vehicles (as defined in the scope of ISO/TC 22, Road vehicles), see ISO 4038, ISO 4039-1 and ISO 4039-2.