1-piece fluted sleeve construction, Ball trust bearing reduces friction in chuck closing mechansim , Through-hardened sleeve teeth, nose, and keyholes for wear resistant , Maximizes gripping force and drilling accuracy , Treated to ensure thread life and high gripping surface hardness , Jaws center-ground for absolute straightness and alignment , For heavy-duty, close tolerance production drilling , For production drilling equipment, jig borers, milling machines, lathes, and radials SKU: ORSNO17580