Aluminum Bars for Electrical Purposes (Bus Bars)

B236: Standard Specification for Aluminum Bars for Electrical Purposes (Bus Bars)

In the realm of electrical infrastructure and power distribution, the integrity and performance of conductor materials are paramount. For engineers and designers specifying components for high-current applications, understanding the material properties and quality standards for aluminum bus bars is essential. ASTM B236 provides an authoritative framework, ensuring that aluminum bars used for electrical purposes meet stringent requirements for conductivity, mechanical strength, and purity. This standard is a cornerstone for reliable and efficient electrical system design.

What is B236?

ASTM B236 is a comprehensive standard specification that defines the requirements for Aluminum 1350 bar intended for use as electrical conductors, commonly known as bus bars. Developed by ASTM International, this proven standard ensures that the material possesses the necessary electrical conductivity and mechanical properties suitable for its demanding application. Its primary purpose is to establish a baseline of quality and performance for procurement and manufacturing processes.

Scope & Purpose

This essential standard governs the manufacture and properties of Aluminum 1350 bar in various tempers, specifically for electrical conductor applications. It details requirements for chemical composition, mechanical properties such as tensile strength and yield strength, and dimensional tolerances. While it focuses on Aluminum 1350, it explicitly references other ASTM standards for different aluminum alloys like Alloy 6101 (Specification B317/B317M), clarifying the scope. The standard does not cover finished electrical assemblies or installation practices.

Who Must Comply?

• • Primary audience: Materials Engineers, Electrical Engineers, Manufacturing Engineers, Quality Control Inspectors, and Procurement Specialists responsible for specifying or verifying electrical conductor materials.
• • Industries affected: Electrical Power Generation and Distribution, Electronics Manufacturing, Industrial Automation, Transportation (including rail and electric vehicles), and Telecommunications.
• • Compliance nature: Voluntary, but often mandated by project specifications, industry best practices, and procurement contracts.
• • Enforcement: Typically enforced through quality control inspections by manufacturers, third-party auditors, and by purchasers during material acceptance testing.

Key Requirements Overview

The standard requires that Aluminum 1350 bar be produced with a controlled chemical composition, primarily focusing on purity to maximize electrical conductivity. Professionals must ensure that the material meets specified minimum tensile and yield strength requirements for mechanical integrity under operational loads. Key provisions include adherence to defined temper designations (e.g., H12, H111, H112) which influence mechanical properties, and compliance with dimensional tolerances as outlined by relevant ANSI standards. The standard also addresses sampling and testing procedures to verify conformance.

Related Standards & References

ASTM B236 is often used in conjunction with other industry-leading standards. ASTM B193 (Test Method for Resistivity of Electrical Conductor Materials) provides the standardized methodology for measuring the electrical resistivity, a critical parameter for bus bar performance. ASTM B317/B317M (Specification for Aluminum-Alloy Extruded Bar, Rod, Tube, Pipe, Structural Profiles, and Profiles for Electrical Purposes (Bus Conductor)) complements B236 by covering other aluminum alloys and product forms suitable for bus conductors. Referencing ANSI H35.1/H35.1(M) (Alloy and Temper Designation Systems for Aluminum) ensures consistent understanding of material designations.