On Dec 31, 12:56*pm, Marv wrote:
On Mon, 31 Dec 2007 09:47:53 -0800 (PST), Tim Shoppa





wrote:
A couple of things I've noticed over the years:

19mm is really really close to 3/4". It's actually 0.748 inches but
I'm not sure any equipment I work with has the bolt heads cut to
better than two thousandths, at least not until I get down to the
pocke****ches :-).

The ratio of height to base for a equilateral (60 degree for all
angles) triangle is really really close to 13:15. (Of course the real
number is sqrt(3)/2 =~ 0.8660, but that's surprisingly close to 13:15
=~ 0.8666).

Is there any deep numerological signifigance to these, or just random
luck?

It is nice to use a 3/4" socket and 19mm socket nearly
interchangeably. I think the spark plug hex on my lawnmower is
officially 3/4" but don't really know. Many (most?) auto lug nuts are
19mm or 3/4" but I don't know which ones are officially which or what.

The 13:15 ratio for an equilateral triangle comes out really nice for
laying out hexagonal grids in "nice" numbers.

Tim.

pi~=355/113 with an error of only 0.002% (22/7 is in error by 0.9%)

Yes, that's true! Next time I go to grab the pi-inches socket and
don't find it, I'll just use the 355/113" socket!

Tim.