Aging Resistant Black O Ring Cord 70 , EPDM Rubber Extrusion FDA TS16949 O-ring cord is extruded rubber in an O shaped section. It is generally available in Nitrile (NBR) FKM (FPM) Silicone (VMQ) and EPDM. Materials. Cord such as EPDM O-ring Cord is generally supplied on coils of varying length, typically 25, 50 or 100 metres dependent upon the cross section or material. Applications of O-ring Cord O-ring cord is generally used to produce O-rings in special sizes which are