Re: [CAD_CAM_EDM_DRO] Re: Stuart 10V Steam Engine

Hi,

Being completely British I will comment a little. First, BA threads aren't
really British at all! They are based on the Swiss Thury thread which is a
version of the metric threads used in watchmaking etc. The idea of the BA /
Thury thread is that each thread has a fixed relationship with the next - to
be specific, 0BA is 6mm (1/4") diameter and each successive one is 90% of
the size of the previous one (i.e. 1BA is 90% the diameter of 0BA, .0209" or
5.3mm instead of 0.236" or 6mm)

So,what is the difference between the two types? Well, the Thury thread also
has sizes larger than 1/4", designated -1, -2 etc. and the thread angle is a
bit different. You can find a listing of most thrad sizes on my web page -
follow the link near the bottom left of centre at
http://www.iw63.freeserve.co.uk
HTH

Ian

--
Ian W. Wright
Sheffield UK

----- Original Message -----
> << I was wondering
> about the "BA fixings", they aren't metric, I wonder how they got
> different from us (or us from them)? A long...long...time....ago. >>
>
> Alan: I have perhaps three or four British friends still living, and
would
> not care to damage any of those relationships. Therefore, may I put my
> answer to your question this way: "I won't touch that!