What’s the difference between EP, EPR, and EPDM?
From a performance standpoint, there is no noticeable difference. EP refers to the ethylene-propylene family of rubber materials. EPR specifically refers to EP copolymer, while EPDM refers to EP terpolymer. EP copolymers must be peroxide-cured, while EPDM polymers can be cured via sulfur or peroxide. While this is important information in terms of O-ring manufacturing, this difference is transparent to the end user.
