The spiral wound gasket is semi-metallic, comprising of a spirally wound v-shaped stainless steel strip and a non-metallic filler material, such as graphite or PTFE. Also on the gasket, is a solid outer ring used for centering and controlling compression.

By definition, a gasket is a mechanical seal that fills the space between two or more mating surfaces, often to prevent leakage while the joined objects are under compression. So, essentially, gaskets fill in the spaces where components of a machine or fixture have gaps.