ASTM International

Standard Specification for Taper Pipe Threads 60° for Thermoplastic Pipe and Fittings
 N F1498

Annotation

This specification establishes requirements for dimensions and gaging of taper pipe threads used on threaded plastic pipe and fittings.

Threads meeting this specification shall only be used on those plastic materials deemed suitable by the manufacturer.

Specialty threads or threads not requiring a leak-tight joint are not covered in this specification.

NOTE 1-The terms "wrench makeup" and "wrench tight" are standard terminology for tightness and do not imply using a pipe wrench or other tools which would damage plastic pipe and fittings. The terms "handtight" and "hand-tight engagement" refer only to thread gaging (not pipe and fitting connections) and is the definition of the L1 gage length.

Thread Designations-The type of pipe threads included in this specification are designated by specifying in sequence the nominal pipe size, number of threads per inch, and the thread series symbols as follows in accordance with ANSI/ ASME B 1.20.1: 3/8-18 NPT. For left-hand threads add LH to the end of the designation, otherwise right-hand threads will be understood. For example: 3/8-18 NPT-LH.

Each of these letters in the symbol has a definite significance as follows:

N = National (American Standard)

P = Pipe

T = Taper

The values stated in inch-pound units are to be regarded as the standard. No other units of measurement are included in this standard.