Vermont American 20373 3/8-18 NPT High Carbon Steel Pipe Tap

3/8inch x 18, National Pipe Taper Tap, Carbon Steel, Ideal For Pipe Fittings, Cuts Internal Threads In Piped, Normal Size Of The Tap Is That Of The Pipe Being Fitted, Tapered At A Rate Of 3/4inch Per Foot, Use 9/16inch Drill Bit, Bulk Pouch.