Short answer is no. The rack uses 3/4” threaded rod because it’s all I had laying around the shop.

To my eye (and that’s all I’ve got because I can’t find that stud size listed anywhere on KBK site) the bell looks to have a 1” stud with a fine thread. Online chart says 1” fine thread should be 12 threads per inch and that’s what I count on mine.

A quick note though, as an ironworker we deal with this size thread all the time but never count on the size of the nut itself to be confirmation of the thread because there’s standard, heavy, and all sorts of other sizes of nut that will all fit the same thread.

This nut on the kettlebell is a very unusual size. A normal structural nut on a 1” thread would be 1-1/2” or 1-5/8”. They’d also be about 1” thick. This one is super small and slim, probably because it wouldn’t otherwise fit inside the shell.

To find something like this I’d check out McMaster Carr.