This SAE Standard specifies the dimensional requirements necessary for the mounting and interchangeability of two types of fuel injectors in diesel engines. The location and dimensions of the fuel inlet, leak-off connections, and flange design are not defined since they may vary according to the particular application. Field of Application This document is applicable to nozzle holder types 5 and 6 of a flange mounted design with a 21.0 mm (nominal) shank diameter used with size "S" nozzles specified in ISO 2697. The internal construction of the fuel injector remains optional with the manufacturer.