Heavy Thickness Tolerances Added to Metallic-Coated Steel Sheet Standard
The revisions to this ASTM standard are a breakthrough in dimensional tolerancing for product and process design.
Posted: December 14, 2014
Recently approved revisions to ASTM International (W. Conshohocken, PA) standard A924/A924M, Specification for General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip Process, will increase the flexibility of the standard.
Hot-dipped galvanized products are important for applications that require the strength and cost effectiveness of steel along with the corrosion protection afforded by zinc coating. “Many users of zinc-coated products are unaware of the recent development of heavier thickness hot-dipped galvanized flat rolled steel,” says ASTM member Ted Armbruster, the vice president of technical services and steel processing at Worthington Industries Inc. (Columbus, OH). “Users and producers did not have dimensional tolerances to refer to when designing their products and processes.”
The primary changes to A924/A924M are the addition of heavy thickness tolerances to Table 2 and Table S1.1. Also, the thickness covered by Table 13 was increased to 0.250 in. These changes ensure that A924 covers heavier gauge zinc coated products that might provide cost-effective alternatives to batch hot-dip coating of finished parts.
A924 is under the jurisdiction of Subcommittee A05.11 on Sheet Specifications, part of ASTM Committee A05 on Metallic-Coated Iron and Steel Products. Armbruster invites all interested parties to join A05.11 in its ongoing maintenance of the standard.
“ASTM A924 is the basic specification for hot-dipped products and is under continual review by producers and consumers of coated steel products,” says Armbruster. “Participation of a broad cross section of users and producers increases awareness of availability and potential new applications for the product.”