The stem diameter is 5/16 inches.
We do not carry a metric version thread. Ours conform to “SAE Standard threads”
No they do not.
these are 5/16
Thank you for your recent inquiry with The Home Depot. Unfortunately, we do not carry this 2 in. Soft Rubber Threaded Stem Casters in brown. For further assistance, please contact your local store or call our Customer Support team at 800-430-3376. We appreciate your business and look forward to serving you in the future. Thank you for shopping Home Depot.
You would need to drill the appropriate size hole in the bed posts and sockets for fitting the threaded stem.
Yes, there is a hex head.
You'll need to drill a threaded hole, and you must consider the leg's area, as it it might shear off.
Yes, 80 lbs capacity per caster.
5/16 x 18