standard specification for deformed and plain carbon-steel bars for concrete reinforcement 1.1 this specification covers deformed and plain carbon-steel bars for concrete reinforcement in cut lengths and coils. steel bars containing alloy additions such as with the american iron and steel institute and the society of automotive engineers 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 are given in table 1. the text of this specification references notes and footnotes which provide explanatory material. these notes and footnotes excluding those in tables shall not be considered as requirements of the specification. 1.2 bars are of three minimum yield strength levels namely 40 000 280 mpa 60 000 420 mpa and 75 000 psi 520 mpa designated as grade 40 280 grade 60 420 and grade 75 520 respectively. 1.3 plain bars in sizes u to and including 2 in. 63.5 mm in diameter in coils or cut lengths when ordered shall be furnished under this specification in grade 40 280 grade 60 420 and grade 75 520. for ductility properties elongation and bending test provisions of the nearest smaller nominal diameter deformed bar size shall apply. requirements providing for deformations and marking shall not be applicable. note 1welding of the material in this specification should be approached with caution since no specific provisions have been included to enhance its weldability. when steel is to be welded a welding procedure suitable for the chemical composition and intended use or service should be used. the use of the latest edition of aws d 1.4 d 1.4m is recommended. this document describes the proper selection of the filler metals and preheat interpass temperatures as well as performance and procedure qualification requirements. 1.4 this specification is applicable for orders in either inch-pound units as specification a 615 or in si units as specification a 615m . 1.5 the values stated in either inch-pound units or si units are to be regarded as standard. within the text the si 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. 1.6 this standard does not purport to address all of the safety concerns if any associated with its use. it is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.