Carefully made by Ruland in Marlborough, MA, these shaft collars are single point faced to ensure bore to face perpendicularity for proper fit and alignment of components. Proprietary processes ensure a good fit, excellent holding power, and a fine burr free finish. Material is 1215 lead free steel with a black oxide finish and forged alloy steel material class 12.9 5/16-24 socket head cap screws. RoHS and Reach compliant. Also called a set collar, single, or 1 piece split collar.