scope:

Listed herein are designations and chemical composition limits for aluminum hardeners registered with The Aluminum Association, Inc. This list is maintained by the Technical Committee on Product Standards of The Aluminum Association, Inc. Additions may be made as required, and hardeners will be deleted when no longer in commercial use. In considering requests for additions, the following criteria apply:

1. The hardener must be offered for sale currently and shall have been sold within the 12 months immediately preceding the date of registration request, in both cases in commercial quantities.

2. The complete chemical composition limits must be disclosed and judged to be reasonable and technically correct by the Technical Committee on Product Standards of The Aluminum Association, Inc.

3. The composition must be significantly* different from that of any hardener for which a numerical designation has already been assigned.

*Significant is defined as:

(a) A change of the following amounts or more in arithmetic mean of the limits for each individual alloying element:

(b) Addition or deletion of one or more alloying elements with limits having an arithmetic mean of 0.20 percent or more.

(c) Change in limits for impurities for which the difference between arithmetic means (existing and proposed) is at least 0.10 percent.

The numerical designations of these compositions were originally assigned in conformance with the system adopted by The Aluminum Association, Inc. in 1973 and approved by the American National Standards Institute, Incorporated, as an American National Standard in 1975 (see American National Standard Designation System for Aluminum Hardeners-ANSI H35.3).

Some of the registered hardeners may be the subject of a U.S. patent or patent application, and their listing herein is not to be construed in any way as the granting of a license under such patent rights.