Nickel-Coated Soft or Annealed Copper Wire

B355-11: Standard Specification for Nickel-Coated Soft or Annealed Copper Wire

In critical electrical applications where reliability and performance under demanding conditions are paramount, the integrity of conductors is non-negotiable. ASTM B355-11 provides an essential framework for specifying nickel-coated soft or annealed copper wire, ensuring that materials meet stringent quality and performance requirements. This authoritative standard is a cornerstone for engineers and designers seeking dependable electrical conductors for challenging environments.

What is B355-11?

ASTM B355-11 is a comprehensive standard that defines the requirements for nickel-coated soft or annealed copper wire intended for use in electrical equipment. Developed by ASTM International, this standard ensures that the nickel coating provides enhanced protection and performance characteristics, such as improved solderability and corrosion resistance, compared to bare copper wire. Its primary purpose is to establish a clear set of material properties, dimensions, and testing methodologies for manufacturers and purchasers.

Scope & Purpose

This standard governs the composition, dimensions, and performance criteria for nickel-coated soft or annealed round copper wire. It specifies five distinct classes of wire based on the weight percentage of the nickel coating (Classes 2, 4, 7, 10, and 27). The standard covers requirements for tensile properties, electrical resistivity, dimensional tolerances, continuity and adherence of the nickel coating, and general finish. It explicitly excludes requirements for stranded wire or wire intended for applications other than electrical equipment.

Who Must Comply?

• • Primary audience: Materials Engineers, Electrical Engineers, Quality Control Inspectors, Production Supervisors, and Purchasing Agents involved in the procurement or specification of electrical conductors.
• • Industries affected: Electrical and Electronics Manufacturing, Automotive, Aerospace, Telecommunications, and any industry utilizing high-performance electrical components.
• • Compliance nature: Voluntary, but often mandated by customer specifications, design requirements, or industry best practices.
• • Enforcement: Typically enforced through contractual agreements, quality assurance programs, and third-party inspections.

Key Requirements Overview

Professionals working with B355-11 must ensure the following:

• • The wire is composed of soft or annealed copper with a specified nickel coating.
• • The nickel coating adheres to specific weight percentages, categorized into five distinct classes (2% to 27% by weight).
• • The wire meets defined tensile strength and elongation properties, critical for mechanical integrity.
• • Electrical resistivity is within specified limits to maintain signal integrity and efficiency.
• • The nickel coating is continuous and exhibits proper adherence to the copper substrate, verified through rigorous testing methods.
• • Dimensional tolerances for wire diameter are strictly maintained to ensure compatibility and consistent performance.

Related Standards & References

ASTM B355-11 often works in conjunction with other ASTM standards. For instance, Specification B258 provides nominal diameters and cross-sectional areas for AWG sizes of solid round wires, which are essential for dimensional control referenced in B355. Test Method B193 is crucial for determining the electrical resistivity of conductor materials, a key parameter specified in B355. These complementary standards ensure a holistic approach to specifying and verifying the quality of electrical conductors.