In article ,
says...
On 14 Jan 2005 20:27:53 -0800, wrote:

Several sources have suggested using a 37/47 gear combination
which is susposed to produce "2/100 of 1% accuracy"
[see http://www.lathe.com/metric_threading]

We can't find a source for those gears either.

Also available from Ametric..

http://www.ametric.com/catalogs.htm

Ned Simmons