Originally Posted by
JohnDThompson
Also crank bolts on some self-extractor mechanisms.
FWIW, 7mm Allen keys are available, but you may have to buy them separately from a set. If you need one, there's no reason not to get one.
I’m aware of the vintage bicycle components that use a 7mm. My point is that they’re rare and haven’t been made in decades, so it makes sense that most current tool sets won’t contain this size.