We are commonly asked whether a porcelain sink is just another name for a fireclay sink. The simple answer is, no.
Although a porcelain sink looks very similar to a fireclay sink they are different. Porcelain is a type of ceramic that is a white clay body made with clay, Kaolin, and other materials, and heated in a kiln at high temperatures to make it durable and hard. In comparison to fireclay, porcelain sinks are made at lower temperatures and are more susceptible to stains, scratches, and chips. They do come in a variety of colors however they are recommended for bathroom sinks and toilets than for kitchens. These sinks are also known as ceramic or vitreous china sinks.
Most porcelain sinks that are made for kitchens are actually porcelain enamel-coated cast iron, stainless steel, or fireclay sinks that are baked at high temperatures. The cast-iron and stainless steel sinks that are glazed with porcelain are strong but can chip if a sharp or heavy object is dropped in. This chip can expose the metal beneath and the damaged enamel will cause the metal underneath to rust. Having said that, with good care, these sinks can also last for decades.