Gaskets are mechanical seals joining two separate parts, filling the space between the parts, and ensuring that conjoining parts are able to seal together in a way that prevents liquids or gases from escaping. A molded gasket is intended to prevent leakage when the part is under pressure, creating a seal that can withstand high pressures and temperatures. For this reason, custom gaskets must be made from materials that can withstand high pressures and temperatures, such as specially formulated rubber compounds. Designing the right molded gasket for any specific application requires an understanding of how the custom gasket will function in the given operating environment.

Sheet gaskets are gaskets punched out of a sheet of rubber material. However, sheet gaskets are not highly durable and may not hold up well to extreme pressure or high temperatures. A molded gasket is typically much sturdier than a sheet gasket. Custom gaskets can also be made from metal. However, custom gaskets made of metal are subject to oxidation in ways that elastomeric gaskets are not, and their sealing properties are quite different from rubber. Spiral-wound custom gaskets have an alternating circle of flexible material along the inside that uses a secondary material such as graphite to create the structural seal, enhancing the strength of the molded gasket.

Custom gaskets produced by a professional and experienced manufacturer will provide the highest quality and durability. Typically, custom gaskets are precisely manufactured to strict specifications and tolerances, and are made with special compounds which ensure a long-lasting seal that does not buckle or break in a high pressure and high temperature environment. The manufacturer's engineering staff will help you design the right type of custom gaskets and select the appropriate material for your application. The finished molded gasket produced by the rubber product manufacturer will be carefully inspected to make sure it adheres to engineering specifications.