Standard Specification for Hard-Drawn Aluminum-Clad Steel Wire

This specification covers four conductivities of bare, hard-drawn, round, aluminum-clad steel wire for general use for electrical purposes. The wire shall be composed of a steel core with a substantially uniform and continuous aluminum covering thoroughly bonded to it. The drawn wire shall have the properties and characteristics prescribed in the specification. The wire of varying nominal diameters shall conform to the prescribed tensile requirements such as tensile strength and elongation. The electrical resistance of the wire shall be determined by resistance measurements and maximum resistance shall be based on the nominal diameter of the wire and the resistivity value. The steel wire shall conform to the prescribed values of physical constants such as modulus of elasticity, coefficient of linear expansion, and temperature coefficient of resistance. Within a required range of diameters, the wire shall not vary from the specified diameter by more than the amount indicated. The aluminum thickness at any point shall not be less than the required values. The wire shall undergo a twist test, where the specimen shall be gripped at its ends in vises, one of which shall be free to move longitudinally during the test. The finished wire shall contain no joints or splices. The material shall also conform to the approximate properties of hard-drawn conductivity aluminum-clad steel wire.