Gearbox mounting stud nuts - what size?

[t20racerman]

Hi all
Had the gearbox off today. Although I had spanners that just about fitted the nuts, I wonder what size they actually are. I tried all kinds of Whitworth and AF spanners and 25/32" was the best fit, although that seemed an unusual size for an A10.
Are they 25/32" or something else?
Thanks
Adrian

[muskrat]

G'day Adrian.
Which nuts are you referring to? My list shows 7/16" but confusion as to CEI or UNF 
Might be of help http://www.baconsdozen.co.uk/tools/conversion%20charts.htm
My bike is buried at the moment.
Cheers

[trevinoz]

BSA used a few 25/32" AF nuts.

[Rex]

Sure they weren't butchered/worn 13/16"? Manufacturers always prefer common commercially-available fasteners.

[RDfella]

20mm? I've found over the years that size is about the only fit on some BSA nuts. Back axle I seem to recall is one.

[Swarfcut]

 My parts books show top and bottom S/A Gearbox mountings to use nuts 02 1925 , which are identified as being 0.782"AF,   0.375" thick and  7/16"  CEI thread.

 Don't shoot the messenger.....that's what it says in the book. 25/32"AF in old money. A BSF or Whit spanner should fit, otherwise it is a shade under 20mm AF.

 Swarfy.

[t20racerman]

My parts books show top and bottom S/A Gearbox mountings to use nuts 02 1925 , which are identified as being 0.782"AF,   0.375" thick and  7/16"  CEI thread.

 Don't shoot the messenger.....that's what it says in the book. 25/32"AF in old money. A BSF or Whit spanner should fit, otherwise it is a shade under 20mm AF.

 Swarfy.

That sounds about right then, 25/32" it is.
Thanks for the help guys, much appreciated. Some of my bikes fasteners have been 'trued-up' and replated, maybe 2 or more times, so the sizes do appear somewhat random at times!
Adrian