The copper 110 shim stock roll is made of a highly conductive, corrosion-resistant metal. Considered the standard copper alloy, this nonmagnetic material contains a minimum of 99.90% copper and has a minimum conductivity rating of 100% IACS (International Annealed Copper Standard). The material has been annealed, a method of heating and cooling a material to reinstate its formability after it has been processed into a shape. This roll conforms to the American Society for Testing and Materials (ASTM) B152, SAE Aerospace Materials Standards (AMS) 4500, and Federal Specification (Fed. Spec.) QQ-C-576 standards.

Shim stock is fabricated by cold rolling, which is the process of reducing a material’s thickness by passing it between two rollers. Cold rolling can cause a temper to form in the material, increasing the yield strength (the amount of force necessary to permanently bend or deform the material) as well as hardness ratings of the material. The higher its hardness and yield strength ratings, the more likely the shim is to preserve its thickness and shape over time while in use, but the harder it will be to bend and shape. Quarter-hard tempered material provides the lowest hardness and yield strength ratings and the greatest ductility of the tempers, with half-hard, three-quarters-hard, full-hard, spring, and blue tempered material respectively increasing in hardness and yield strength. Annealed shim stock has been heated and cooled to remove any temper and reinstate the material’s natural formability (ability to be bent) after it has been cold rolled.

Shim stock, which is sold in either sheets or rolls, is a very thin material that can be cut, sawed, stamped, milled, or bored into specific shapes. These fabricated pieces, also called shims, can be placed between objects for a variety of uses, including added support, improved leveling, increased insulation, tighter sealing, and better spacing. Shims can also be used to fill in gaps between machine parts that are prone to wear, avoiding costly replacement parts and lost production time. While most shim stock is sold in standard thicknesses of solid material, shim stock with laminated layers is composed of stacked foil sheets that have been pressed and heated together and that peel off to adjust the shim’s thickness to the application.