Greetings Kees!

 BF>>    I know. Some people here in Sweden too was foolish enough to by
 BF>> products from countries with the archaic units. Including me, with
 BF>> my old Matchless -54 bike...

 KvE>  Yes great, the same inch based spanners, but with Witworth tread, a
 KvE> different pitch from the inch based UNF.

But the same as the 'inch based UNC' threads with, as you point out, a
different thread angle.  50ø vs 60ø...

 KvE> There was another difference as well, the angle of the thread
 KvE> flanks.

I don't understand 'thread flanks' - Would you be referring to pitch
angle? As in the example above.

 KvE>  But to be true, first there was witworth, all the others were
 KvE> incompatible.

Not so...see my other msg to Felten regarding Whitworth vs SAE threads.


    Have a day!

         R\%/itt - K5RXT

... WH advisor says that voters are stupid; slighting the majority of
    Democrats (liberals) who voted for the O'bama, not once, but twice.

--- GoldED+/W32 1.1.5-31012
--- D'Bridge 3.99