Re: Whitworth

["Mike Kitchener" <mikek@wanadoo.fr>]

 Karl Vacek wrote :

> Whitworth wrench sizes correspond to the nominal diameter of 
>the fastener
> - ie, a 1/2" wrench fits the head of a standard BSF or BSW screw or bolt. 
> Of course if the head is NOT standard, then...
> 
> But who'd ever expect anything non-standard on a British car???

FWIW
B.S.Whitworth parallel screw threads
extracts from BS 84 and BS 916
  Nominal dia.       tpi         across flats mini       across flats maxi
      1/4"               20               0.435"                      0.445"    
        
         
      5/16"             18               0.515"                      0.525"

      3/8"               16               0.585"                      0.600"

      7/16"             14               0.695"                      0.710"
  
      1/2"               12               0.800"                      0.820"
 
      5/8"               11               0.900"                      0.920"   

       6"                 2.5              9.325"                      9.450"

Cheers

Mike .

///  triumphs@autox.team.net mailing list
///  To unsubscribe send a plain text message to majordomo@autox.team.net
///  with nothing in it but
///
///     unsubscribe triumphs
///
///  or try  http://www.team.net/cgi-bin/majorcool