... &no go gauge 4"NPT thread Machined by CNC and NC Machine Sand Casting Pump Inlet FlangeGrey IronChecked by Go&no ... go gauge4"NPT threadOil coatedSuperior corrosion resistanceMachined by CNC and NC MachineCheck 4"NPT thread by gaugeStandard: ASTM, BF,BS, JIS ... Bar and steel plate, Drilling, Milling, Turning, Boring, Slating, Grinding,, NC/CNC Machining etc.4) Tolerance is controlled by CMM Machine ...