Obviously other than the name!

hank bush is for sheet
rivnut is for tube however it can be used for sheet as well

Hank bush is "splined" and an interference fit into a hole with itself only on one side.

Rivnut is around both sides of the hole and crimped onto it.

rivnut is a 'blind' fastener so it's useful on tube - hank bush you need to access round the back.
Bob

top one is a rivnut
Rescued attachment hank.JPG

Hank bushes are almost as strong as conventional nuts.

Rivnuts are a weaker option.

They both have their uses, but in highly stressed parts of the chassis I prefer to weld (Tig) in threaded bosses,
as large drilled holes in the chassis are weak points. (IMHO)


Paul G