AASHTO M 31M/M 31-19 covers deformed and plain carbon and low-alloy steel concrete reinforcement bars in cut lengths or coils. Steel bars containing alloy additions, such as with the AISI and SAE series of alloy steels, are permitted if the resulting product meets all the other requirements of this specification. The standard sizes and dimensions of deformed bars and their number designations shall be those listed in Table 1. Bars are of four minimum yield strength levels: namely, 280 MPa [40,000 psi], 420 MPa [60,000 psi], 520 MPa [75,000 psi], and 550 MPa [80,000 psi], designated as Grade 280 [40], Grade 420 [60], Grade 520 [75], and Grade 550 [80], respectively. Bars that have carbon contents limited to 0.30 percent or less, and that meet the carbon requirements of this specification, shall be designated as Type W. Bars that have carbon contents greater than 0.30 percent shall be designated as Type S.