Steel fiber refers to fibers with a length-to-diameter ratio of 40 to 80, which are produced by cutting fine steel wires, cold rolling steel strip shearing, ingot milling, or rapid cooling of molten steel. When the fiber cross-section is not circular, the diameter is calculated based on the equivalent circular area of the cross-section.

Steel fiber performance varies with different production methods. Although steel fiber has been around for a short time, its applications are expanding and the variety is increasing.

To ensure a more even distribution of steel fibers in mortar or concrete and to increase the length-to-diameter ratio of the fibers, bundled steel fibers bonded together with water-soluble adhesives can be used. Steel fibers can be manufactured through methods such as cutting cold-drawn steel wire, shearing thin steel plates, milling steel blocks or ingots, and drawing molten steel. For steel fiber concrete used at room temperature, low-carbon steel fibers can be used; for fire-resistant steel fiber concrete, stainless steel fibers are required. The addition of an appropriate amount of steel fibers to mortar or concrete can enhance their tensile and flexural strength, as well as significantly improve their toughness and impact resistance.