In article , The Chairman wrote:

Thanks, I'll try that. Forgive my ignorance, but is plywood also subject to
this same phenomena? IE: is 3/4" actually 1/2"?

The reason that a two-by-four, for example, is actually 1.5" x 3.5" is that
it's rough-sawn at the mill to 2" x 4". Then it shrinks some as it dries.
Finally, it's planed smooth, which reduces it to the finished size of 1.5" x
3.5".

This obviously isn't the case with plywood.

However... some years back, a bean counter working for one of the plywood
manufacturers figured out that they could get about three percent more plywood
sheets from the same amount of raw material by reducing the thickness
slightly. Nominal 3/4" plywood is usually 23/32" thick. Nominal 1/2" plywood
is usually 15/32". And you can't depend on nominal 1/4" plywood being
anywhere even close to 1/4" -- I've seen some that's _less_than_ 3/16" being
sold as "quarter-inch".

Having said that, if you sandwich two pieces of nominal 3/4" plywood together,
the result will be close to 1.5", but not exactly, more like 1 7/16".


--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?