OM86-2 OM86 Series Hollow Cutter is designed to cut away swaged or threaded collars from fasteners so that the fastener pin can be easily removed. The OM86-2 OM86 Series Hollow Cutter is best used for removing Hi-Shear® rivets. The rotating cutter on the Omega Technologies Hollow Collar Cutter is applied to the collar until a sufficient amount of collar material has been removed. The pin can then be easily removed with a punch. Microstop cage is typically used with the Omega Technologies Hollow Collar Cutters to prevent the cutter teeth from contacting and damaging the work surface.