Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical Purposes

B246-15: Standard Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical Purposes

For engineers and designers working with electrical conductors, ensuring the reliability and performance of copper wire is paramount. ASTM B246-15 provides an essential, authoritative framework for specifying and procuring tinned hard-drawn and medium-hard-drawn copper wire, crucial for a wide array of electrical applications where corrosion resistance and conductivity are key. This standard is a cornerstone for quality assurance in the manufacturing of vital electrical components.

What is B246-15?

ASTM B246-15, "Standard Specification for Tinned Hard-Drawn and Medium-Hard-Drawn Copper Wire for Electrical Purposes," establishes the material properties, dimensional tolerances, and performance requirements for copper wire that has been coated with tin. Originating from ASTM's commitment to developing industry-leading standards, its primary purpose is to ensure a consistent, high-quality product suitable for demanding electrical applications.

Scope & Purpose

This comprehensive specification governs the characteristics of round copper wire intended for electrical use, specifically focusing on wire that is both hard-drawn or medium-hard-drawn and subsequently tinned. It defines acceptable limits for dimensions, tensile strength, elongation, resistivity, and the continuity and adherence of the tin coating. The standard excludes requirements for insulated wire or wire intended for other than electrical conductor purposes.

Who Must Comply?

• • Primary audience: Materials Engineers, Electrical Engineers, Quality Control Inspectors, and Manufacturing Technicians involved in the specification, production, or inspection of electrical conductors.
• • Industries affected: Electrical Equipment Manufacturing, Electronics, Telecommunications, Aerospace, Automotive, and any sector utilizing tinned copper wire for conductivity and corrosion resistance.
• • Compliance nature: Voluntary, but widely adopted and often specified in procurement contracts, making it de facto mandatory for many supply chains.
• • Enforcement: Typically enforced through contractual agreements and quality control inspections by manufacturers, end-users, and third-party certification bodies.

Key Requirements Overview

The standard requires that tinned wire be manufactured from high-purity copper, ensuring excellent electrical conductivity. Professionals must ensure the tin coating is commercially pure and applied as a smooth, continuous, and well-adhered layer to prevent corrosion. Key provisions include strict adherence to specified diameter tolerances, ensuring consistency in dimensional properties. Furthermore, the standard mandates specific tensile strength and elongation values for both hard-drawn and medium-hard-drawn conditions, guaranteeing mechanical integrity. Electrical resistivity limits are also defined to ensure optimal conductivity at a standard temperature.

Related Standards & References

ASTM B246-15 often works in conjunction with other ASTM standards. For instance, ASTM B193 provides the authoritative test method for determining the electrical resistivity of conductor materials, which is referenced for compliance with B246-15's resistivity requirements. Additionally, ASTM B5 and ASTM B170 are foundational specifications for the high-conductivity copper refinery shapes used as the raw material, ensuring the base metal meets stringent purity and electrical property standards.