We did customs tooling. In the 80s 90s it was inch sizing and inch components. Late 90s still inch tooling but Metric components, and so drawings would have REAM for .236 Dowel ( instead of 6mm) LOL
In mid 2000s tooling was metric sized as long as it was close to a purchasable inch size from the steel foundary. So block would be 608mm wide, to order a 24" block.
So 2025 mostly you can see places working full metric.
Then there are places I have worked recently that still use Fractional inch on projects and then wonder why assembly problems arise. Like design intent is 8.541 and maybe clearance to adjacent part has to be .039". Drawing has 8 9/16 + 1/32, so not only is sizing wrong compared to mating part, the fractional inch means dude uses a tape measure by eye, rather than a 3 place decimal measure tool.
It’s such a mess.
I have seen US companies try, but it is so slow.
We did customs tooling. In the 80s 90s it was inch sizing and inch components. Late 90s still inch tooling but Metric components, and so drawings would have REAM for .236 Dowel ( instead of 6mm) LOL In mid 2000s tooling was metric sized as long as it was close to a purchasable inch size from the steel foundary. So block would be 608mm wide, to order a 24" block.
So 2025 mostly you can see places working full metric.
Then there are places I have worked recently that still use Fractional inch on projects and then wonder why assembly problems arise. Like design intent is 8.541 and maybe clearance to adjacent part has to be .039". Drawing has 8 9/16 + 1/32, so not only is sizing wrong compared to mating part, the fractional inch means dude uses a tape measure by eye, rather than a 3 place decimal measure tool. It’s such a mess.