For those of you new to laminated metals, here is a quick lesson in terminology. Often, people will refer to laminated metals by stating a composition (comp), type, and class. These denote the following:

Compositions-
Composition 1 - Aluminum
Composition 2 - Brass
Composition 3 - Corrosion Resisting Steel (Stainless Steel)
Composition 4 - Carbon Steel

Types-
Type 1 - Fully laminated
Type 2 - One-half solid stock
Type 3 - Three-fourths solid stock

Classes-
Class 1 - .002 inch laminations
Class 2- .003 inch laminations