... :9001;High quality OEM is ok. Hard alloy gun drill in latheTungsten tip with alloy stell shankDifferent specifications.OEM ... hole processing machinery, machining center, turning center etc satisfy gun drill cooling and guidance request the equipment of carbon steel, ... a professional factory mainly manufacturing Diamond/CBN Grinding Wheels, Gun Drills, Diamond Oilstone, Grinding Paste, and Grinding File ...