Rubber sheets are rubber molded into flat sheets with an even thickness and are often sold on a roll of a specific length for easy handling. Common thicknesses of rubber sheets vary from super-thin films to 1/4-inch (6.53 mm) thick; the thickness of the sheet combined with the type of rubber used in the sheet determine its use. Once the material type is known, tools designed to cut through the rubber are used to cut different shapes from the sheet to form gaskets. The gaskets cut from rubber sheeting keep fluids and gases from penetrating products or keep them contained within vessels or low-temperature mechanical systems.
Tools designed to straight cut rubber sheets vary depending on the thickness of the material. Sharp utility knives and scissors cleanly cut rubber sheeting measuring less than 3/4-inch (19.05 mm) thick. Larger stamping press-type cutters are required to cut through thicker rubber sheets. A straight clean cut through rubber sheets is vital to the success of the finished gasket's ability to seal the area between parts. Cutting small holes in a rubber sheet requires tools that remove rubber from the area rather than drilling material from the sheet.
Leather punches starting at 1/8-inch (3.175 mm) diameter and larger are used with hammer or mallet-cut circular shapes in a rubber sheet. The thickness of the rubber sheet determines the amount of force required to send the cutting end of the punch through the rubber sheet. Using drill bits in an attempt to place holes in a rubber sheet causes the rubber to heat up and bind to the fluted shaft of the drill bit, tearing the area around the hole. Mishandling the rubber sheet also leads to brittleness and eventual tears across the sheet's surface. Proper handling techniques extend the life of the rubber sheet both before and after cutting.
Neoprene and other dark-colored rubber sheeting breaks down when exposed to ultraviolet (UV) light. Keeping rubber sheeting out of direct sunlight ensures the bonds in the rubber sheet do not break down and allow the rubber to become brittle. Cracks running across the surface of a rubber sheet are the first sign that the rubber has broken down and become unusable. Chemicals and petroleum products will also break down the bonds in a rubber sheet and cause the sheet to weaken and become brittle. Storing a rubber sheet properly ensures the rubber remains usable.
