On Sun, 04 Dec 2011 18:40:40 -0500, Dave M. wrote:
http://home.comcast.net/~sday77/bink...l_Can_Spec.pdf

I like that PDF. But it showed some weird things!

I thought it strange that the can only need handle 15 psi (since I'm told
the vapor pressure of gasoline is 22 psi) but I guess it's close enough
for government work.

Also, it seemed odd that a 'venting port' was allowed - since the whole
point of the California gas cans is that there is no longer a separate
venting port (it's in the spout now - but that makes the spout nearly
useless as fuel flow is severely restricted).

However, the diagram of the threads seemed to be the wierdest feature.

1. At the top of the threaded neck, the diameter to the outside peak of
the threads seems to be 3.400 inches (+- 0.030 inches).
2. Yet, the last thread of the threaded neck, 1.20 inches later, seems to
enlarge that to 3.480 inches (+- 0.030 inches).
3. And, each thread seems to be 0.016 inches tall.

I wonder why they make the last thread bigger? Is it to make is super air
tight? Wouldn't normal threads be just as air tight?

3. The pitch seems to be 1/4 inch between threads, comprised of a 0.100
inch (+- 0.20 inches) peak, and the rest is a funny shape of 10 degree
and 32 degree angles.

Overall, that's a weird shape!

But at least we now know the shape.

I wonder if it has a specific name like most other threads do?