I believe the term you're looking for is "Bell Glide". You might have luck with 3/8" which is 9.53mm. They're still more difficult to find but here are two options:
https://smile.amazon.com/Master-Caster-70178-Profile-Glides/dp/B001MS70J8
https://chaircaps.com/products/hsig38sfglide-screw-in-38x16-thread-with-superfelt.html?gclid=Cj0KCQiA09eQBhCxARIsAAYRiym9bZ3g9sop8SnOPTqiMxgzFlgVVYahZdDlq7zi0TfdVvQlItc2V9saApxJEALw_wcB (dunno how a screw one will work)
It will probably be a lot easier to find locking wheels in the 3/8" diameter though: e.g https://smile.amazon.com/Hirate-Threaded-Casters-Locking-Workbench/dp/B08QRRLMRR/