On Mon, 19 Feb 2018 00:38:25 +0000, alan_m
wrote:

On 19/02/2018 00:23, ultred ragnusen wrote:
wrote:

That's strange that Europeans use a half-metric half-what-you-call-Imperial
standard of units.

Not necessarily the rest of Europe but the UK.

Do the Germans and French also use "inch" sizes for their ratchets?

I believe it's an international standard with no metric equivalents for
the "drive" side of sockets.
It's an accepted international standard - but there ARE others -
including hex drive inch and metric, as well as hex "through" sockets
with inch or metric, and likely half a dozen or more other "odball"
configurations.