Flat washers are usually used in a connection member, a soft texture and a hard brittle texture, and its role is to increase the contact area, spread the pressure and prevent the texture of soft crushed. The basic action of the spring washer spring nut, then tighten the nut after a force, increasing the friction between the nut and bolt! Material 65Mn (spring steel), heat treatment hardness HRC44 ~ 51HRC, by surface oxidation.
Rubber gasket materials usually NBR (D *** gum), SBR (styrene butadiene rubber), HNBR (hydrogenated butyl rubber ***), EPDM (ethylene propylene diene monomer rubber), SILICONE (silica), VITON (** * rubber), CR (*** butadiene rubber), FFKM (full *** rubber) and the like.
Rubber gasket material selection to NBR butyl rubber *** most widely used, its highest price. The whole FFKM rubber gasket *** using generally the more cutting-edge fields such as space rocket. Because its price is quite expensive, but its performance may be more than many metal materials.