DIYGUY wrote:

... answer me this question. If a caster wheel is rated at a load
carrying capacity (which it is) how is the rating determined? I have a
600# tool I want to put on casters. Does each caster have to be rated
at 600# or can I get four casters, one on each corner, that are each
rated at 150# (or more) load bearing capacity?

This is important because casters with higher load bearing capacity are
much larger and I want to keep the added height of the tool down to the
bare minimum. Thanks all for your answers ...

Strictly depends on the load balance...if it is a uniform load, the
weight is shared equally by all four. (To visualize, think of you
standing up straight, weight on both feet--each is half your total. Now
slouch and put your weight on the one--it's carrying essentially the
whole load.)

I'd oversize by some, even though there will be a safety factor in the
design (unless they're a really, really cheap import and then I wouldn't
trust the rating, anyway) primarily because the heavier ones will roll
easier if they're not at the load range limit and the installation will
just feel more solid.

Someone else suggested 200#/ea--that would be a good target methinks.