Lackmond TK4SPP 4-Inch Tuck Pointing Wheel with 7/8-5/8 Arbor Bushing .250" width with a harder bond Used on more abrasive materials and cleaning mortar joints Respected in the masonry, waterproofing, and restoration trades Useful in coring or crack chasing applications and should be used in very shallow cutting Generally have a longer life span than other small-diameter segemented blades, making the blades a worthwhile investment