The steel bracket is very thick, a bit thicker than the small wheel products on the market. Cast iron wheels are very suitable for storage cabinets that have to be in one place for a long time or need to be heat resistant.
Very thick, that is true for both steel bracket and PA wheel. The caster itself is heavy and have strength to support up to few tons per caster. The Swivel head is combined of Flat and Cone Bearing so you will have no trouble operating.