ISO 228 - Pipe Threads where Pressure Tight Joints are not made on the Threads
The ISO 228 "Pipe Threads where Pressure-tight Joints are not made on the Threads" consists of the following parts:
- ISO 228-1:2000 Dimensions, tolerances and designation
- ISO 228-2:1987 Verification by means of limit gauges
| G Size (in) | Major (Outside) Diameter (mm) | Minor (Nut) Diameter (mm) | Core Hole Diameter (mm) | Thread Count (TPI) | Thread Pitch (mm) |
|---|---|---|---|---|---|
| G 1/8 | 9.73 | 8.85 | 8.80 | 28 | 0.907 |
| G 1/4 | 13.16 | 11.89 | 11.80 | 19 | 1.337 |
| G 3/8 | 16.66 | 15.39 | 15.25 | 19 | 1.337 |
| G 1/2 | 20.95 | 19.17 | 19.00 | 14 | 1.814 |
| G 5/8 | 22.91 | 21.13 | 21.00 | 14 | 1.814 |
| G 3/4 | 26.44 | 24.66 | 24.50 | 14 | 1.814 |
| G 7/8 | 30.20 | 28.42 | 28.25 | 14 | 1.814 |
| G 1 | 33.25 | 30.93 | 30.75 | 11 | 2.309 |
| G 1 1/8 | 37.90 | 35.58 | 35.30 | 11 | 2.309 |
| G 1 1/4 | 41.91 | 39.59 | 39.25 | 11 | 2.309 |
| G 1 3/8 | 44.32 | 42.00 | 41.70 | 11 | 2.309 |
| G 1 1/2 | 47.80 | 45.48 | 45.25 | 11 | 2.309 |
| G 1 3/4 | 53.74 | 51.43 | 51.10 | 11 | 2.309 |
| G 2 | 59.61 | 57.29 | 57.00 | 11 | 2.309 |
| G 2 1/4 | 65.71 | 63.39 | 63.10 | 11 | 2.309 |
| G 2 1/2 | 75.18 | 72.86 | 72.60 | 11 | 2.309 |
| G 2 3/4 | 81.53 | 79.21 | 78.90 | 11 | 2.309 |
| G 3 | 87.88 | 85.56 | 85.30 | 11 | 2.309 |
| G 3 1/4 | 93.98 | 91.66 | 91.50 | 11 | 2.309 |
| G 3 1/2 | 100.33 | 98.01 | 97.70 | 11 | 2.309 |
| G 3 3/4 | 106.68 | 104.30 | 104.00 | 11 | 2.309 |
| G 4 | 113.03 | 110.71 | 110.40 | 11 | 2.309 |
- TPI stands for Threads Per Inch and is a count of the mumber of threads per inch. TPI is used for American fasteners.
- Thread pitch is the distance between the threads and is used for metric fasteners.
- G-threads have a parallel shape in accordance with the DIN-EN-ISO 228-1 standard with flank angle 55o.
- G/R/Rp - Whitworth Pipe Threads (BSPP/BSPT)
- ISO 7-1 Pressure Tight Thread Joints
Example - Typical designation for Thread according ISO 228
- ISO 228 G 3 1/4"
Related Topics
• Dimensions of Pipes and Tubes
Pipe, tube and fittings sizes and dimensions. Inside and outside diameters, weights and more.
• Threads
Thread data - metric, unified, ACME and others.
Related Documents
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EN 10226 - Pipe Threads where pressure tight joints are made on the threads - Dimensions
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ISO 724 - Metric Threads
Dimensions of metric threads according ISO 724.
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Whitworth Pipe Threads
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Taps and drill sizes used for Whitworth - ISO 7 and ISO 228 threads.