Good-bye backaches. Save your sacroiliac with a 3-wheeled professional mover's dolly. It measures 6-3/8" wide between a trio of swivel casters with 1-9/16" x 11/16" wheels, and has a drop-down center and a 1/2" dia hole for permanent attachment to frequently moved items. Steel construction, 110 lb max load (so not piano-duty), and rubber pads above each wheel. Stands 2-1/2" tall. We think ordering (4) would be a good place to start.

These light-duty plastic casters are on swiveling stems and have dual 1-1/2" dia x 5/16" wheels in 1-7/8" x 1-3/16" hemispheric housings. Stems are striated steel, 3/8" dia x 3/4" long. We're thinking these would be fine for your average chair. Our each is a bag of (4).

You’re on a roll. You’ve been on a roll for years and you know it. Keep it going with this set of (6) 5/8" dia steel ball casters on 2" x 1-3/8" plates with 5/32" mounting holes. Rated for a max load of 35 lbs, and come on, you’ve got a million things under 35 lbs that need rolling.

These little swivel-plate casters look like they should be on the bottom of one of those spinner carry-on suitcases. In flat black, they have (2) 1-1/8" dia x 3/8" plastic wheels (approx 1-1/4" thick) on a 1/4" stem and a 1-1/8” square steel plate with 3/16" mounting holes at the corners. Make a rolling file, or your own  spinner luggage.

Our 4" dia swivel-stem casters have 3/4" wide dual black-plastic wheels and 1" steel stems with 1/2" - 13 threads. No weight limit listed, but they're pretty sturdy, and pretty snazzy, at least to the extent that casters admit of snazziness.