Zinc-Coated Parallel and Helical Steel Wire Structural Strand

A586-04a: Standard Specification for Zinc-Coated Parallel and Helical Steel Wire Structural Strand

For engineers and designers involved in critical infrastructure and structural applications, understanding the properties and performance of high-strength steel wire strand is paramount. ASTM A586-04a provides an essential framework for specifying and procuring this vital component, ensuring reliability and longevity in demanding environments.

What is A586-04a?

ASTM A586-04a is the authoritative standard specification for zinc-coated steel wire structural strand. Developed by ASTM International, this comprehensive document details the requirements for manufacturing and quality of steel wire strand intended for use as a tension member in various structural applications. Its primary purpose is to ensure that the strand possesses consistent tensile strength, durability, and corrosion resistance through a controlled zinc coating process.

Scope & Purpose

This industry-leading standard governs the properties of zinc-coated steel wire strand, available in both parallel and helical constructions. It specifies requirements for base metal composition, zinc coating weights (Classes A, B, and C for outer wires, with Class A mandatory for inner wires), and mechanical properties such as tensile strength and stress at 0.7% extension. The standard is applicable to strand intended for use as a high-strength, high-modulus tension member. It does not cover the design or application of the strand itself, which falls under the purview of structural engineering codes.

Who Must Comply?

• • Primary audience: Materials Engineers, Structural Engineers, Quality Control Inspectors, Procurement Specialists, and Manufacturers of steel wire strand and related structural components.
• • Industries affected: Construction, Civil Engineering, Infrastructure Development (including bridges, towers, and transmission lines), and Steel Manufacturing.
• • Compliance nature: Voluntary, but widely adopted and often mandated by project specifications and procurement documents to ensure product quality and performance.
• • Enforcement: Typically enforced through contract specifications, third-party inspections, and adherence to material certifications provided by manufacturers.

Key Requirements Overview

The standard requires that the base metal be of high-quality carbon steel. Professionals must ensure that the zinc coating applied to the wires meets specified weight classes (A, B, or C for outer wires) to provide adequate corrosion protection. Key provisions include detailed mechanical property requirements for the individual wires and the finished strand, including minimum breaking strength and the stress at 0.7% extension under load. The standard also outlines testing procedures to verify these properties and mandates that calculations for tensile strength be based on the actual cross-sectional area of the finished wire, including the coating.

Related Standards & References

ASTM A586-04a is often used in conjunction with other ASTM standards. ASTM A90/A90M (Test Method for Weight [Mass] of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy Coatings) is crucial for verifying the integrity of the zinc coating. ASTM A902 (Terminology Relating to Metallic Coated Steel Products) provides essential definitions for clarity. Furthermore, ASTM B6 (Specification for Zinc) details the requirements for the zinc used in the coating process, ensuring material purity.