为增强砂浆或混凝土而加入的、长度和直径在一定范围内的细钢丝。常用截面为圆形的长直钢纤维，其长度为10～60毫米，直径为0.2～0.6毫米，长径比为50～100。为增加纤维和砂浆或混凝土的界面粘结,可选用各种异形的钢纤维,其截面有矩形、锯齿形、弯月形的;截面尺寸沿长度而交替变化的；波形的;圆圈状的;端部放大的或带弯钩的等。
Fine steel wire of a certain length and diameter added to strengthen mortar or concrete. The length of the steel fiber is 10-60 mm, the diameter is 0.2-0.6 mm, and the length diameter ratio is 50-100. In order to increase the interface bonding between fiber and mortar or concrete, various special-shaped steel fibers can be selected, whose cross-sections are rectangular, zigzag, crescent shaped; cross-section size changes alternately along the length; wavy; circular; end enlarged or with hook, etc.
为使钢纤维较均匀地分散于砂浆或混凝土中，并增大纤维的长径比，可使用由水溶性胶粘结在一起成集束状的钢纤维。钢纤维可用冷拔钢丝切断、薄钢板剪切、钢块或钢锭铣削以及熔钢抽纱等方法制造。配制常温下应用的钢纤维混凝土，可使用低碳钢纤维；而配制耐火的钢纤维混凝土，则必须使用不锈钢纤维。砂浆或混凝土中掺加适量的钢纤维，可提高其抗拉、抗弯强度，并大幅度地提高其韧性和抗冲击强度。
In order to make the steel fiber more evenly dispersed in the mortar or concrete, and increase the length diameter ratio of the fiber, the steel fiber which is bonded together by water-soluble adhesive can be used to form bundles. Steel fiber can be made by cutting cold drawn steel wire, cutting thin steel plate, milling steel block or ingot, and drawing yarn of molten steel. Low carbon steel fiber can be used to prepare steel fiber concrete applied at room temperature, while stainless steel fiber must be used to prepare fire-resistant steel fiber concrete. Adding proper amount of steel fiber into mortar or concrete can improve its tensile strength, bending strength, toughness and impact strength.