NOTE: The main dimensions were converted into millimeters on the basis of 1inch =25.4mm, beginning with the number of threads per inch, which determines the pitch P, the formula h (the height of thread) = 0.640 327 P and then major diameter at the gauge plane. Pitch diameter and minor diameter were then compiled by subtracting once or twice respectively the height of thread h iron from the major diameter. 

The nominal gauge length, the tolerances and the fitting were directly computed. The remaining lengths given in above table were obtained by subtracting or adding the tolerances or fitting allowance respectively to the nominal gauge length. Tolerances and fitting allowance are expressed in millimeters and in turns of thread.

1) For parallel internally threaded parts the diametral tolerances are derived from the tolerances in column 14 by multiplying with corresponding pitch in column 3 and with 1/16, the amount of taper.
2) Informative tolerances, in millimeters, are obtained from the mandatory values in turns of thread by multiplying with the corresponding pitch in column 3 and rounding to the nearest 0.1 mm.

Tolerance on outside Diameter, Wall Thickness, Weight & Length of Pipe

ASTM Std. A53 Welded Steel Pipes and Seamless Steel Pipes
Available Sizes ( Dimensions and Weights)