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New Specification for Annealed Copper-Clad Steel Wire Has Worldwide Applications

A proposed ASTM specification for annealed copper-clad steel wire will set requirements for bare round copper-clad steel used globally in numerous products in electrical, electronic, grounding, telecommunications, and other applications.

“This specification can be used all over the world,” said Metallurgical Engineer William Malone, technical manager, bimettalics, Copperweld Corp., Fayetteville, Tenn. “The existing standard written about 30 years ago only has 30 to 40 percent conductivity with high carbon steel cores listed and doesn’t cover all of the latest products available. There are other conductivities made today with 21 to 70 percent conductivity and lower carbon steel cores.” Four conductivities are covered in the draft specification: 21, 30, 40, and 70 percent.

Malone, who chairs Subcommittee B01.06 on Composite Conductors in Committee B-1 on Electrical Conductors, will coordinate preparation of the draft with input from users who represent electric utility transmission engineers, manufacturers of communication, transmission and specialty cables, and secondary producers who manufacture smaller diameter wire for the wire and cable industry.

“Primarily, we’re adding two more categories of conductivity and making the standard specific to annealed wire,” he said. “The existing specification, B 452, [ASTM Standard Specification for Copper-Clad Steel Wire for Electronic Application] is for hard and soft wire but only in high-carbon steel. The new specification will cover high and low carbon steel; a wider range of product offerings that have never had a specification for the users. In small quantity, this wire is in many of the commercial jet airplanes; in very small quantities, it is in most of the satellites. It’s also used for lead wires in electronic components.”

Malone said the largest use of copper-clad steel is covered in ASTM B 869, Standard Specification for Copper-Clad Steel Electrical Conductor for CATV Drop Wire, regarding the center conductor wire for coaxial television drop-cable that passes from the utility pole into the home television. “The ‘pin’ protruding from the cable is actually copper clad steel wire,” he said. The subcommittee’s new draft specification for annealed copper-clad steel wire will cover all other applications in electronics, telecommunications, and power in some instances.

The draft is projected for placement on first subcommittee ballot this month. Subcommittee B01.06 also plans to develop a similar standard for the same products in the hard drawn wire condition.

For further information, contact William Malone, Copperweld Corporation, 254 Cotton Mill Rd., Fayetteville, TN 37334-0070 (931/433-0418; fax: 931/433-0470). Committee B-1 meets during ASTM Committee Week, April 12-13, in Toronto, Ontario, Canada. For meeting or membership information, contact B-1 Staff Manager Felicia Quinzi, ASTM (610/832-9738). //