The purpose of this book is to enlighten humanity and contribute to the general betterment of this orb that we call home. Failing that, we will settle for giving engineers enough guidance in the use of aluminum that they will feel confident designing with it. The Aluminum Association, an industry association of aluminum producers, publishes the Specifications for Aluminum Structures (hereafter called the Aluminum Specifications), which are the generally accepted criteria for the design of aluminum structures. This book is keyed to the sixth edition of the Aluminum Specifications, and readers should have access to it.