EPDM washers are designed to be tightened to a required torque beneath an ordinary fastener. They exert a soft tension that keeps the fastener from vibrating loose. They are still used on many applications in the belief that they will"lock" the nut/bolt to the joint and prevent loosening, and also used for Self drilling screw.
Material: EPDM and Carbon Steel/Stainless Steel
Applications: Be used for Self drilling screw
Color：EPDM has Black, gray