Tube OD mm 4 5 6 8 10 12 14 16 18 20 22 25 28 32 34 40 42 NPTRG 1/8" 1/4" 3/8" 1/2" 3/4" 1" 11/4" 11/2" Metric Thread M10x1 M12x1.5 M14x1.5 M16x1.5 M18x1.5 M22x1.5 M27x2 M33x2 M42x2 M50x2 Model sample:Tube OD is ?12,terminal thread is R3/8" and max working pressure is 25Mpa ,the ream joint with taper thread is marked :Q/ZB204-77R1" ?28