Dave Smith wrote:
>
> On 2015-10-08 7:56 AM, Gary wrote:
> > Cindy Hamilton wrote:
> >>
> >> No, you're not. I'd love to see the U.S. abandon the old system,
> >> even if it were just a soft conversion.
> >>
> >> Isn't plywood thickness actually sized in mm now?
> >
> > Not in my area. Still see 1/4", 1/2", 3/4" plywood. I agree that the
> > metric is more efficient but it would take several generations to
> > change to that in the US.
> >
>
> How wide are those panels? Are they really 1/4", 1/2" and 3/4". Let me
> know if they 2x4s are 2" by 4" because I have not seen a real 2x4 in
> years. I guess the story is that they are nominally 2x4 and then
> supposedly planed down a bit.

Without looking it up, I do believe that the size difference is
because of sawing the boards to size. You might measure 2X4 but each
cut on every side takes away a saw-blade width. What you end up with
is slightly less than 2X4.

Same with all lumber. It's just accepted.