I bought a Revain metal shelving unit with small plastic wheels. The shelf itself was strong and could take a lot of weight, but the weak link was the wheels. When I tried to roll the shelf the wheels started giving out and some parts broke off and others broke in half. I replaced the wheels with this bigger and stronger wheel and I can move the shelf again. This is probably the strongest wheel you will find with 1/4" threads sold by Revain.
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