The committee for AISC 370-21, Specification for Structural Stainless Steel Buildings, identified several issues with A484/A484M. The revision schedule for AISC 370 was just moved up by 2 years and final changes will be balloted in February 2024, making it necessary to ballot these A484/A484M issues on an emergency basis.
While this standard covers both extruded and hot rolled shapes, that is not clear from the title and the scope. This has been corrected.
Structural engineers expect stainless steel hot rolled shapes to have the same dimensional tolerances as A6/A6M carbon steel hot rolled shapes but the A484/A484M hot rolled shape tolerances are less comprehensive and looser. Purchasers have been ordering hot rolled shapes using both the relevant stainless steel standards and ASTM A6 tolerances, which is problematic. This revision replaces the existing hot rolled shape tolerance tables with A6 tables. Furthermore, A484/A484M limited the size of hot rolled sections to 3 inches when sizes of up to 6 inches are available. The tables from A6/A6M were modified, as required, to adjust for this size limitation.
The maximum size for extruded sections was not consistent in this standard and was corrected. Scope sections 1.6 and 1.7 were replaced with the wording from A994, which provides A01’s formatting requirements. The terminology section of A6/A6M has been referenced so that there is hot rolled shape definition consistency between standards. An informational note was added to summarize the requirements for welded sections in ASTM and AISC 370 when larger structural sections are needed.
Only the changes marked in underline and strike-through format are being balloted.