This International Standard specifies the main characteristics of M14 x 1,25 spark-plugs with conical seating with normal or long reach and their cylinder head housing, for use with spark -ignition engines.
SIS SS-ISO 2344:1989 history
1989SIS SS-ISO 2344:1989 Road vehicles - M14 x 1,25 spark-plugs with conical seating and their cylinder head housing