In article , Larry Blanchard wrote:
On Sat, 20 Aug 2011 20:53:17 +0000, Doug Miller wrote:

No he doesn't, he wants 1/4" and 6mm doesn't equal that. Close but no
cigar, so much for metric unless you can measure 6.35mm on that tape

Do you *really* think that 0.35 millimeters (less than 14 thousandths of
an inch) is going to be noticeable? Or are you just trying to be
argumentative?

I bought some wood taps and dies once to make some wooden vise screws. I
used a 1" dowel (yes it was 1") for the screw. I cut threads in it and
the hole to receive it with no problem. But the screw wouldn't fit.

Turns out the tap and die were 25mm, not 1" (25.4). So yes, it can make
a difference.

I got a fresh dowel and turned it down to 25mm or a little less.

Totally different context. When you're talking about fitting a shaft into a
hole, tolerances of 0.005" or less can be critical. When you're talking about
a border around something, the difference between 1/4" and 6mm is unlikely to
be important to anyone, or indeed even noticeable.