spanners

[cajmal]

anyone inform me about spanner sizes please,are bsf, whitworth and af the same sizes needed for my seagull engines .i am a bit confused thanks

[Vic]

BSF/Whitworth sizes required. Sizes refer to the thread size

Metric sizes are mm "across the flats"
American UNF and UNC are fractions of an inch across the flats

Useful explanation and table of spanner jaw sizes at http://www.sat.dundee.ac.uk/~psc/spanner_jaw.html