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BSP-British Standard Pipe Threads - Dimension Chart (BSPP = British Standard Pipe Threads Parallel, BSPT = British Standard Pipe Threads Taper)

For Non-Pressure-tight Joints

BSP-British Standard Pipe Threads for Non-Pressure-tight Joints BS 2779:1973 are Withworth from parallel fastening threads that are generally used for fastening purpose such as the mechanical assembly of component parts of fittings, cocks and valves. They are not suitable where pressure-tight Joints are made on the threads.

For Pressure-tight Joints

BSP-British Standard Pipe Threads for Pressure-tight Joints BS21:1973 are based on the Withworth thread form and are specified as Joint threads. These relate to pipe threads for joints made pressure-tight by the mating of the threads; they include taper external threads for assembly with either taper or parallel internal threads (parallel external pipe threads are not suite-able as jointing threads).

*** All dimensions are given in inches.

Nominal Size
Threads per Inch
Depth of Thread
Major Diameter
Pitch Diameter
Minor Diameter
1/16
28
0.0229
0.3041
0.2812
0.2583
1/8
28
0.0229
0.3830
0.3601
0.3372
1/4
19
0.0337
0.5180
0.4843
0.4506
3/8
19
0.0337
0.6560
0.6223
0.5886
1/2
14
0.0457
0.8250
0.7793
0.7336
5/8
14
0.0457
0.9020
0.8563
0.8106
3/4
14
0.0457
1.0410
0.9953
0.9496
7/8
14
0.0457
1.1890
1.1433
1.0976
1
11
0.0582
1.3090
1.2508
1.1926
1 1/4
11
0.0582
1.6500
1.5918
1.5336
1 1/2
11
0.0582
1.8820
1.8238
1.7656
1 3/4
11
0.0582
2.1160
2.0578
1.9996
2
11
0.0582
2.3470
2.2888
2.2306
2 1/4
11
0.0582
2.5870
2.5288
2.4706
2 1/2
11
0.0582
2.9600
2.9018
2.8436
2 3/4
11
0.0582
3.2100
3.1518
3.0936

 

***** The above data sheet can be used for information purpose only. No responsibility can be accepted for errors or omissions by whatever cause.

 

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