The Dubo retaining washer deforms in the toothed collar washer as a direct result of tightening the bolt. This deformation is necessary to obtain the desired locking and sealing; in fact, this principle underlies Dubo products. Under high pressure, the Dubo retaining washer is perforated by the teeth of the toothed collar washer. This causes deformation in which the toothed collar washer forms a solid unit with the bolt. The bolt is then in direct contact with the steel teeth, creating a partly rigid connection of steel/steel and nylon, and a constant elasticity of the retaining washer.