This specification covers two grades of uncoated low-relaxation@ seven-wire steel strand for use in pretensioned and post-tensioned prestressed concrete construction. Grade 1725 [250] and Grade 1860 [270] have minimum ultimate strengths of 1725 MPa [250 ksi] and 1860 MPa [270 ksi]@ respectively@ based on the nominal area of the strand. The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text@ the inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore@ each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The supplementary requirements in S1 shall be specified for 15.24-mm- [0.600-in.-] diameter uncoated seven-wire steel strand if needed for applications in prestressed ground anchors.