How straight is straight enough? How flat is flat enough? Some products need to be manufactured to more exacting standards than others, and these standards should be mutually agreed upon prior to production. The specified, acceptable range of deviation from a given dimension is known as a tolerance.

Aluminum profiles can be extruded to very precise special tolerances, as well as accepted standard dimensional tolerances. Some engineers and designers call for geometric dimensioning and tolerancing, also referred to as geometrics. This has been described as a modern technical language with uniform meaning that can be used to specify the shape-related intricacies of a design, allowing for improved communications between the designer and the manufacturer.

Meeting tolerances ensures product performance and reduces the need for additional machining. Aluminum extrusion allows for the precision needed to produce the expected fit and function.

Tolerance Tables
Standard dimensional tolerances for extrusion are explained with illustrated examples in the Extrusion Manual, available for purchase in the Publications section. The Manual also contains information on geometric dimensioning and tolerancing.

A new tolerance table, including precision tolerances, was published by The Aluminum Association in July 2006. This excerpt from Aluminum Standards & Data, © 2006 The Aluminum Association, Inc., is used with permission. Copies are available for purchase through the Aluminum Association at www.aluminum.org/bookstore.