HEAVY DUTY SIOUX STYLE VALVE SEAT GRINDER STONE HOLDER THREAD 11/16" With DIAMOND STONE DRESSER FOR BLACK & DECKER, SIOUX, KWIK KAY 0.50 CARAT DRESSER QUANTITY - 5 NOS THREAD SIZE: 3/8" X 24UNF LENGTH - 60MM - 2.3/8" The Bearings Are Initially Crafted to resist the vibration during use and Special Treatments for Extra Long Life.