Platens flat cooking surfaces provide a method for efficient twosided cooking, while accommodating a variety of products. Platens are made of either stainless steel or a composite material. Operators can specify grooved platens for items that require grill markings. Manufacturers recommend the use of nonstick sheets for the top platen since it is difficult to scrape off food. Without the sheet, the top of a burger or other food can stick to the platen, compromising its quality. Sheets last about two weeks with good maintenance. A shim is a washer or thin strip of material used to align parts, make them fit, or reduce wear. Shims may also be used as spacers to fill gaps between parts subject to wear. On machinery installations pumps, motors, etc. the recommended practice requires new shims to be placed under every supporting foot. Specifications. Position Lower. Gauge 16. Size 0.05 in.. Height 0.01 in.. Width 2.1 in.. Length 2.1 in.