Historical
ISO 8470:2001
Road vehicles -- M14 x 1,25 spark-plugs with flat seating and 16 mm hexagon and their cylinder head housings
This International Standard specifies the main characteristics of M14 × 1,25 spark-plugs with flat seating and a hexagon smaller than the seating diameter, and their cylinder head housings, for use with spark-ignition engines.
International Organization for Standardization [iso]