steel - an alloy of iron with small amounts of carbon; widely used in construction; mechanical properties can be varied over a wide range

drill rod, drill steel - carbon steel used for rock drills and dowels

eutectoid steel - a steel that contains 0.9% carbon (the eutectic point in the iron-carbon system); a carbon steel with 0.9% carbon is pure pearlite

hyper-eutectoid steel - a steel that contains more than 0.9% carbon

hypo-eutectoid steel - a steel that contains less that 0.9% carbon