1.78° 90° 1.78° 1.78° 90° 1.78° THREADING Steam, gas andwater pipes Pipe couplingsfor food and fireMotion transmissionfighting industries Aircraft andaerospace Oil and gas Taper Pipe American Round ISO Trapezoidal American UNJ API Buttress API Round Thread NPTF DIN 405 30° ACME Casing Casing & Tubing BSPT r=0.137278P r=0.221047Pr=0.255967P 0.125P 27.5°27.5° 30° 30° 30° 30° 29° 60° 30° 30° 10° 3° 90° r=0.137278P r=0.238507P 0.366P 0.3707P r=0.18042P 90° BSPTR(PT)Rc(PS) NPTF RdRp Tr(TM) ACME(Tw) UNJ BCSG CSGLCSG thread/inch thread/inch thread/inch mm thread/inch thread/inch thread/inch thread/inch 28 27 10 1.5 12 32 16 5 10 19 18 8 2.0 10 28 14 8 14 14 6 3.0 8 24 12 11 11.5 4 4.0 6 20 10 8 5.0 5 18 8 G – – – – – – – – G005