On Wed, 27 Jul 2011 18:58:55 -0400, "Ed Huntress"
wrote:


wrote in message
.. .
The standard taper 3/4 inch per foot is listed in Machinery's Handbook
as 3, 34, 47. When I calculate it I get 3,34,34. I get this answer
using my TI calculator and my computer. Looking on the web I find the
3,34,47 answer. It's the angle I've always used. So how come I get
something different? On my TI-30X calculator I divide .75 by 12 which
equals .0625. This is the tangent. I then use the inverse tangent
function to get the answer: 3.576334375. Then I use the DDDMS
function which returns the answer: 3,34,34 80. So what's going
on??????
Thanks,
Confused machinist Eric

Sorry if this adds to the confusion, but my _American Machinist's Handbook_
(1940 edition) says 3 deg., 34 min., 44 sec. for the included angle at 3/4
in. per foot.

My HP 15C gives me 3,34,34.8.
So your book is also wrong. At least I'm not so confused now.
Eric