Blistered Steel
A remarkable modification of iron intermediate between cast and wrought iron, containing less carbon than cast iron, but more than wrought (about 1 1/2 per cent). It is made by imbedding bars of best wrought iron in powdered charcoal in boxes or sand-furnaces which exclude the air, and heating intensely for a week or ten days. The steel, when withdrawn, has a peculiar, rough, blistered appearance, and for this reason is called blistered-steel. See CEMENTATION; CAST STEEL.