It can be made hard enough to cut glass, or pliable enough to serve as a paper clip or the sheet used for the springs of automobiles or typewriters, or rigid, for the wheels of rail cars. It can be drawn into wire a thousandth of an inch thick or fabricated into giant girders for bridges and buildings. It can be made resistant to heat, rust and chemical attack.The basic materials from which steel is made iron ore, bituminous coal and limestone are abundant.