AASHTO M 255M/M 255-19涵盖了按照机械性能要求生产的热锻、特殊质量的碳素钢棒和棒尺寸形状，适用于一般建筑应用。钢筋有九个强度等级，分别为310、345、415、450、485、515、550和620[45、50、55、60、65、70、75、80和90]，对应于最小极限抗拉强度（单位:MPa[ksi]）。化学成分由制造商选择，以形成所需的机械性能。受机械性能要求约束的热锻、特殊质量碳素钢棒仅以直线长度热锻。ASTM A 29/A 29M涵盖了可用的截面和尺寸。注:M 227M/M 227涵盖了符合机械性能要求的商用质量热锻碳素钢棒。

AASHTO M 255M/M 255-19 covers hot-wrought, special quality, carbon steel bars and bar size shapes produced to mechanical property requirements and intended for general constructional applications.The bars are available in nine strength grades designated 310, 345, 415, 450, 485, 515, 550, and 620 [45, 50, 55, 60, 65, 70, 75, 80 and 90] corresponding to the minimum ultimate tensile strength in MPa [ksi]. The chemical composition is selected by the manufacturer to develop the required mechanical properties.Hot-wrought, special quality, carbon steel bars subject to mechanical property requirements are hot wrought in straight lengths only. Sections and sizes available are covered in ASTM A 29/A 29M.Note: Merchant quality, hot-wrought carbon steel bars subject to mechanical property requirements are covered in M 227M/M 227.