Abstract: A fastening for mounting on a pipe shaft or hollow polygonal cross-sectional shaft for use in a business machine or other industrial machine to hold an element on the shaft. The fastening has a ring having a gap at a peripheral portion, the portions of the ring on opposite sides of the gap being a pair of holding arms extending peripherally toward the gap, the holding arms having the ends opposed to each other and spaced slightly less than the diameter of the pipe and positioned a little past a diameter through the center of the ring and perpendicular to a diameter extending through the gap. Each holding arm has a curved holding surface at the end thereof on the inside of the ring for intimate engagement with the shaft.