Not all Router bits are created equalThese cutters are a fast, efficient way to rout slots and grooves for T-moldings, spline joints, tongue & groove joints and many other applications. Should be used with Freud?s slotting cutter arbors 60-100 for 1/4? shanks, 60-102 for 1/2? shanks, and 62-108 bearing.USER BENEFITS & FEATURES:Requires Freud arbor and bearing, sold separately.Cuts all composition materials, plywood, hardwood, and softwood.Use in hand-held and table-mounted portable routers.