These are simple 1/2" thick flat rings that the OEM lug bolts go through, not the bolt-on ones with their own studs- - - -I wouldn't use that kind of thing on a lawn mower! The wheels just need a bit more clearance to keep from rubbing the calipers. I might even be able to machine them down to 3/8" thick once I check on the clearance.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!