Just finished this set. Black walnut and maple blanks. The hardware is from Lee Valley .
The insert gets glued in the blank with the metal cap screwing on. I wasn't super happy with the kit because it's expensive and needs odd-sized holes. I bored undersized (7/8โ) and expanded with a square end scraper, but the taper on the tubes makes it difficult to get a snug, consistent fit. Had to use some blue tape to shim the gap.
Bigger holes on pepper, more small holes on salt!