Abstract: A combined threaded fastener and a collar adapted to be secured to the fastener around the shank portion of the fastener adjacent the head thereof. The shank portion of the fastener is adapted with a shoulder portion disposed adjacent the head portion and extending lengthwise of the shank of the threaded fastener for a predetermined extent. Adjacent the shoulder is an annular groove which in the preferred embodiment is generally circular in cross-section. The collar has an annular flange which serves as the bearing portion and is adapted to cooperate with the head portion of the fastener and a sleeve portion attached or extending longitudinally of the flange or bearing portion. The sleeve portion has a diameter sufficient so as to receive the shank portion of the fastener therein. The sleeve portion of the collar is also adapted with an annular groove which again in the preferred embodiment is substantially of circular cross-section.