Ferrous (iron-containing) material that generally is re-melted and recast into new steel. Integrated steel mills use scrap for up to 25% of their basic oxygen furnace charge; 100% of the mini-mills' raw material for their electric furnaces generally is scrap. 
Home (Revert) Scrap Waste steel that is generated from within the steel mill, through edge trimming, rejects and metallic losses in slag. It normally is sent directly back to the furnace. 
Prompt (Industrial) Scrap Excess steel that is trimmed by the auto and appliance stampers and auctioned to scrap buyers as factory bundles. This is a high-quality scrap as the result of its low-residual content and consistent chemistry. 
Obsolete (Reclaimed) Scrap Iron-bearing trash. Automobile hulks, worn-out refrigerators and useless storage tanks, for example, can be recovered from the junkyard and re-melted. The residual impurity of such scrap normally relegates obsolete scrap to the mini-mills (see No. 1 Heavy Melt).