The 300 series stainless steel shim stock with full hard temper has an unpolished (mill) surface and a standard tolerance, and meets American Society for Testing and Materials International ASTM A666 specifications. The 300 series stainless steel grade provides good resistance to corrosion and high temperatures. It may be slightly magnetic. The full hard temper is harder and has a higher yield strength than 3/4 hard temper to better resist deformation.

Shim stock is very thin material that can be fabricated into specific shapes. Yield strength is the maximum stress a material can withstand before it will no longer return to its original shape. Corrosion resistance describes the material's ability to prevent deterioration caused by atmosphere, moisture, or other medium. Wear resistance indicates the ability to prevent surface damage caused by contact with other surfaces. Toughness describes the material's ability to absorb energy before breaking, while hardness (commonly measured as indentation hardness) describes its resistance to permanent surface deformation. Formability indicates how easily the material can be permanently shaped. Machinability describes how easily it can be cut, shaped, finished, or otherwise machined.