$60.99 Free shipping 1pc HSS NPT/Z 1/4 18 Pipe Taper Tap hss machine taps for pipes inner threading 
WIDELL 1 1/4 11 BSPP HSS PIPE TAP 6 FLUTE 1.25 UK WHITWORTH 303041 RP1 1/4 55 | eBay
Drill America 1/4 in. -18 Carbon Steel NPT Pipe Tap-DWTPT1/4 - The Home Depot
