熟铁是含碳量小于0.02%的铁合金碳钢，又称纯铁（含碳量在0.02－1.7%称为钢，含碳量在1.7－4.3%则称生铁）。

熟铁由铁矿石用碳直接还原，或由生铁经过熔化并将杂质氧化而得到的产物；前者冶炼温度较低，采用比较早，后者温度虽然较高，但生铁去碳后由于熔点增高而变稠；两者都不易使渣和铁完全分离，所以熟铁中常含有少量的渣，在加工后显示纤维组织。

中国在春秋、战国时代已经使用生铁，估计熟铁的发展时间当更早。

熟铁较软，具有较好的抗腐蚀性，韧性和延展性较高，硬度和强度较低。

Wrought iron is an iron alloy with a very low carbon (less than 0.08%) content in contrast to cast iron (2.1% to 4%). It has fibrous inclusions known as slag up to 2% by weight. It is a semi-fused mass of iron with slag inclusions which gives it a "grain" resembling wood, that is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile, corrosion-resistant and easily welded. Before the development of effective methods of steelmaking and the availability of large quantities of steel, wrought iron was the most common form of malleable iron.