I lifted this list of acceptable whitworth equivalents from a land rover site. Some of them are identical to .001"
Whitworth = SAE or Metric
1/8 = 11/32
3/16 = 7/16
1/4 = 17/32
5/16 = 19/32
3/8 = 18mm
7/16 = 21mm
1/2 = None
9/16 = 1"
5/8 = None
I think headsets are 1" Whitworth and I haven't found an exact equivalent.
Last edited by pfaustus; 07-12-18 at 10:10 AM.