ASME’s widely-referenced B1.20.1 Standard on Pipe Threads, General Purpose, Inch covers dimensions and gaging of the world’s most common pipe threads: NPT, NPSC, NPTR, NPSM, and NPSL. This long awaited revision incorporates both subtle and substantive changes, including: Moving of the gaging point of reference of external threads in certain circumstances; A new acceptability section for instances of gaging disputes; A change to parameters, facilitating the calibration of working gages; Guidance for plated or coated pipe threads; Better explanatory language for the lay-user.