This specification covers two types and two grades of 2- and 3-wire, uncoated weldless steel and strand for use in pretensioned and posttensioned prestressed concrete construction. One specimen for test shall be taken from each production lot of finished strand and tested for breaking strength, yield strength and elongation. Strands of Grades 250 and 270 shall conform to specified breaking strength and yield strength requirements. Low relaxation strand shall also be tested as prescribed.

1.1 This specification covers two types and two grades of 2- and 3-wire, uncoated steel strand for use in pretensioned and posttensioned prestressed concrete construction. The two types of strand are low-relaxation and stress-relieved (normal-relaxation). Low-relaxation shall be regarded as the standard type. Stress-relieved (normal-relaxation) strand will not be furnished unless specifically ordered, or by arrangement between purchaser and supplier. The two grades are 1725 (250) and 1860 (270). Grades 250 and 270 have minimum tensile strengths of 1725 MPa (250 ksi) and 1860 MPa (270 ksi) respectively, based on the nominal area of the strand.

1.2 The values stated in either inch-pound units or SI units are to be regarded as the standard. Within the text, the inch-pound units are shown in parentheses. 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.