This 4 x 1-1/2 Cast Iron Swivel Caster or “semi-steel” is a strong, durable and cost effective solution that can carry heavy loads. Featuring a weight capacity of 600 lbs. and an operating temperature range of -45° to +600° Fahrenheit, they roll easily on clean, debris free floors. This wheel is not recommended for wet environments as it can rust.
For more info, check out Caster Wheel Types.