FED-STD-143A, FEDERAL STANDARD: SPARK PLUG; HEAT RATING OF, METHOD OF CLASSIFYING (09 AUG 1960) [S/S BY SAE-J2162]

FED-STD-143A, FEDERAL STANDARD: SPARK PLUG; HEAT RATING OF, METHOD OF CLASSIFYING (09 AUG 1960) [S/S BY SAE-J2162]., The purpose of this Federal Standard is the establishment of uniform heat rating descriptions for use in classifying spark plugs of the unshielded type. The content of this standard is for use in describing unshielded spark plugs, procured, catalogued, stocked, or used by the Government.