Tin Mill Products, Electrolytic Tin-Coated, Cold-Rolled Sheet

A599/A599M: Standard Specification for Tin Mill Products, Electrolytic Tin-Coated, Cold-Rolled Sheet

In the demanding world of metal fabrication and packaging, ensuring material integrity and performance is paramount. The ASTM A599/A599M standard provides an authoritative framework for electrolytic tin-coated, cold-rolled steel sheet, a critical material for applications demanding corrosion resistance and excellent solderability. Understanding this comprehensive specification is essential for manufacturing engineers and production managers aiming for consistent quality and efficient production.

What is A599/A599M?

ASTM A599/A599M is a leading industry standard that precisely defines the requirements for cold-rolled steel sheet coated with tin through an electrolytic process. Developed by ASTM International, this specification ensures that the material possesses the necessary characteristics for a wide array of applications, particularly in the food and beverage packaging, appliance, and automotive sectors, where reliability and surface quality are non-negotiable.

Scope & Purpose

This essential standard governs the production and quality of electrolytic tin-coated, cold-rolled steel sheet, specifying its base metal properties, tin coating weight, and available finishes. It details requirements for both inch-pound and SI units, ensuring global applicability. Importantly, A599/A599M does not cover steel sheets lighter than 0.015 in. (0.381 mm), for which a separate standard applies, nor does it cover hot-rolled products.

Who Must Comply?

• • Primary audience: Materials Engineers, Production Engineers, Quality Control Inspectors, Purchasing Agents, and Metallurgists.
• • Industries affected: Steel Manufacturing, Metal Fabrication, Packaging (especially food and beverage), Automotive, Appliance Manufacturing, and general metal goods production.
• • Compliance nature: Primarily voluntary, but often a mandatory contractual requirement when specified by purchasers.
• • Enforcement: Typically enforced through contractual agreements, supplier audits, and customer qualification processes. Third-party testing can also be used to verify compliance.

Key Requirements Overview

The A599/A599M standard outlines several critical requirements for manufacturers and users:

• • Base Metal Quality: The base steel must conform to general requirements for cold-rolled sheet as defined in ASTM A568/A568M, with specific steel grades (e.g., Commercial Steel, Deep Drawing Steel) chosen based on application needs.
• • Tin Coating: The standard specifies the method of tin application (electrolytic) and defines various coating designations, including unmelted and melted finishes, to meet different performance and aesthetic demands. Weight of coating is precisely defined and tested.
• • Surface Finishes: Professionals must ensure the correct base metal finish (e.g., No. 5 or No. 7) is specified and applied, as this significantly impacts the final product's appearance and performance, particularly with organic coatings.
• • Dimensions and Tolerances: Suppliers must adhere to strict dimensional tolerances for thickness and width, consistent with general requirements for cold-rolled sheet.
• • Protection and Handling: The standard addresses the application of protective oil films to prevent surface damage during transit and handling, crucial for maintaining material integrity.

Related Standards & References

To ensure comprehensive material control