Norm ASTM B0228-04
1.1 This specification covers bare concentric-lay-stranded conductors made from bare round copper-clad steel wires for general use for electrical purposes.
1.2 For the purpose of this specification, conductors are classified as follows: Grade 40 HS, Grade 30 HS, and Grade 30 EHS.
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.