In Brazil manual tap and die
sets are only available for metal or PVC tubing,
which are not appropriate for use with wood. I
have experimented with several alternatives, but
none was satisfactory. With wood, dies made for
metal leave fragile threads prone to breaking.
A common threaded nut can be
made to work as a die, as shown on some videos
available on the Internet, but they are not as
practical as they might seem.
So I turned to old methods, and to
the masters, including Roy Underhill, who, in
addition to his fantastic videos, describes how to
make these tools in his book The Woodwright's Workbook.
Another important source is André Roubo’s Le
Menuisier Ébéniste, which was published in 1774 and has a
perfect description of these thread cutters, along with a
beautiful engraved illustration. [Plate 311-trans.]
understand the secrets of hardening and tempering metal
parts I went to Alexander Weygers. His book
The Complete Modern Blacksmith shows how to make metal
both hard and strong, using simple and available techniques.
Following these and other references I
describe in this article how to make manual tap and screwbox
sets as an inexpensive alternative, using scraps and
available supplies, as efficient as those made centuries