DIMENSIONS OF PIPE THREADS
 
British Standard Threads
 
British Engineering Standard Association Reports No. 21 - 1938 Forms of British Standard Pipe Threads.
 

DIMENSIONS OF PIPE THREADS

UNIQUE CORPORATION
   
Table 1 Basic Sizes Dimensions in inches
Nominal Bore of Pipe Approximate Outside Diameter of Black Pipe Number of Threads Per inch

Pitch

 Depth of Thread Diameter at Gauge Diameter from End (Gauge Dia)

Distance of Gauge Diameter from End (Gauge Length)

 Length of Useful Thread
  A   P h B F E
1/8 0.400 28 0.03571 0.0229 0.383 0.1563 0.2545
1/4 0.538 19 0.05263 0.0337 0.518 0.2367 0.3814
3/8 0.676 19 0.05263 0.0337 0.656 0.2500 0.3947
1/2 0.847 14 0.07143 0.0457 0.825 0.3214 0.5178
3/4 1.063 14 0.07143 0.0457 1.041 0.3750 0.5714
1 1.336 11 0.09091 0.0582 0.309 0.4091 0.6591
1 1/4 1.677 11 0.09091 0.0582 1.650 0.5000 0.7500
1 1/2 1.909 11 0.09091 0.0582 1.882 0.5000 0.7500
2 2.381 11 0.09091 0.0582 2.347 0.6250 0.9204
2 1/2 2.996 11 0.09091 0.0582 2.690 0.6875 1.0511
3 3.499 11 0.09091 0.0582 3.460 0.8125 1.1761
3 1/2 3.991 11 0.09091 0.0582 3.950 0.8750 1.2386
4 4.494 11 0.09091 0.0582 4.450 1.0000 1.4091
5 5.493 11 0.09091 0.0582 5.450 1.1250 1.5795
6 6.501 11 0.09091 0.0582 6.450 1.1250 1.5795
 
. American Standard Threads
Approved by American Standard Association B2.1 1945 Forms of American Standard Pipe Threads.
 

American Standard Threads

UNIQUE CORPORATION
 
Table 2 Basic Diamensions Dimensions in Inches
 
Nominal Pipe Size Outside Diameter of Pipe Threads per inch

Pitch of Threads

 Hand -Tight Engagement

Effective Thread Length External

 Depth of Thread
  D n P L1 E1 L2 h
1/8 0.405 27 0.03704 0.180 0.37476 0.2639 0.02963
1/4 0.540 18 0.05556 0.200 0.48989 0.4018 0.04444
3/8 0.675 18 0.05556 0.240 0.62701 0.4078 0.04444
1/2 0.840 14 0.07143 0.320 0.77843 0.5337 0.05714
3/4 1.050 14 0.07143 0.339 0.98887 0.5457 0.05714
1 1.315 111/2 0.08696 0.400 1.23863 0.6828 0.06957
1 1/4 1.660 111/2 0.08696 0.420 1.58338 0.7068 0.06957
1 1/2 1.900 111/2 0.08696 0.420 1.82234 0.7235 0.06957
2 2.375 111/2 0.08696 0.436 2.29627 0.7565 0.06957
2 1/2 2.875 8 0.12500 0.682 2.76216 1.1375 0.10000
3 3.500 8 0.12500 0.766 3.38850 1.2000 0.10000
3 1/2 4.000 8 0.12500 0.821 3.88881 1.2500 0.10000
4 4.500 8 0.12500 0.844 4.38712 1.3000 0.10000
5 5.563 8 0.12500 0.937 5.44929 1.4063 0.10000
6 6.625 8 0.12500 0.958 6.50597 1.5121 0.10000