[mark-r]

We may get there eventually just as a consequence of being part of the world economy.

I noticed a couple of years back that my "U.S. Customary" wrenches weren't fitting my new plumbing fittings which were definitely not metric, but metric wrenches did. Probably made in China.

Then last summer I noticed something similar with lag bolts. The U.S. Customary socket fit the head, but it was nearly identical to a metric one that fit just a little better. The threads are designed to go into wood, not a nut, so if they were metric you'd never even know.