ISO 2974:2013 specifies the dimensional requirements of end-connections for high-pressure fuel injection equipment components used on diesel (compression-ignition) engines.
It is applicable to externally threaded 60° female cones and intended for use with high-pressure fuel injection pipe assemblies with tube outside diameters of
- up to and including 12 mm for integral female cones, and
- up to and including 9 mm for fabricated female cones.
Details of the pipe connection ends referenced in this document are shown in ISO 13296.