Bugbear asked:

>Does anyone know the pitch of large (e.g. 2")
>wooden screws?<

I'm tempted to reply, as Bugbear himself so often
does, with just a URL:

http://www.fine-tools.com/gewind.htm

But no, there's no way I can restrain myself from
talking; you'll be lucky to escape in an hour (see you
this albatross around my neck?)

The Schmid 2" screwbox (at the url) has a pitch of 2.5
t.p.i. and their 2.5" screwbox has a pitch of 2 t.p.i.
 By the way, I have one of their 1.25" models, and it
is a superb tool and my pride and joy as a pressmaker.
I wish I could afford the big ones.

The Schmid sizes are right in line with historic
practice. I have measured perhaps half a dozen
binders' presses with screws in the 2" to 3" range and
the pitch is in the range of 2 to 3 t.p.i.; probably
2.5" and 2 t.p.i. is most typical. It isn't absolutely
standard: I am pretty sure that I have seen 2" screws
pitched as fine as 3 and as coarse as 2, and I am
pretty sure I have seen 2.5" screws as fine as 3
t.p.i.  I have an old woodworkers vise screw, so badly
cracked that it is unusable, and I think this is 3"
and 2 t.p.i.  I don't think I have ever seen a screw
larger than 3" or coarser than 2 t.p.i. (I have data
on this, but it is at home and I am going from
memory). A lot of 1.75" screws seem to be 2 t.p.i., if
I remember correctly.

The Schmid screwboxes and taps are rougly ten times
the price of the common Taiwanese ones where sizes are
comparable (approx. $350 opposed to approx. $35 for
1-1/4"). For 1" and finer the cheap ones are perfectly
OK. However, for all sizes over 1" the Taiwanese boxes
are pitched too fine; and using the German ones is a
joy: they are stable, clean-cutting, and easy to
adjust.  More than worth the extra money for them as
has it.

Tom Conroy
Berkeley

		
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