An item designed to be mounted around a shaft to limit axial movement of the shaft and/or its assembled parts. it is secured directly to the shaft by use of a setscrew(s), pin(s), or the like, which may be a part of the item of supply. a pilot hole drilled in or through the wall(s) for drilling and pinning at application may be considered a method of securing. solid items have a bearing surface on one or both end(s) perpendicular to the axis. for items designed to be mounted around the extended hub portion of a mounted item on a shaft or clamp around a shaft, see clamp, hub. see also bearing, sleeve; bushing, sleeve; spacer, sleeve; and coupling, shaft, rigid.