I had this same problem! Problem solved quick and easy! I ran a 20mm Park wrench right up a 20mm grinding wheel! The 20 mm grinding wheel was a little bit bigger than 20mm, zapped it real fast and I had my 21mm wrench! Nice even cut, cleaned it up a little and it fitted just fine. I know the wheels in the States are probable sized different! Do note! Wear gloves eye protection and be careful!
This only happened by chance.
BC..................And the gang!!
Renaissance cycles,
Eindhoven Holland.
> Listmembers,
>
> I need a thin 21 mm wrench. Doesn't need to be quite as thin as a
> cone wrench. It's for a locknut on a BB spindle, so it must fit
> between the BB shell and the outer locknut. I'd say 3 mm max.
> thickness.
>
> Looking through the VAR catalog, I see 22 mm and up for BBs, and up
> to 18 mm cone wrenches.
>
> I know Park makes a 20 mm cone wrench. But no 21s!
>
> I guess I could buy a standard 21 mm wrench (if available - my
> wrenches skip that size and go from 20 to 22 mm!), and grind it
> thinner.
>
> Thanks for your help.
>
> Jan Heine, Seattle