HoseFitFinder: ranked by major diameter
Updated 05 September 2026.
168.27 mm
6-8 NPT leads on major diameter
The highest major diameter is 6-8 NPT at 168.27 mm.
| Rank | Model | Major diameter |
|---|---|---|
| 1 | 6-8 NPT | 168.27 mm |
| 2 | 4-1/2-4NH | 146.3 mm |
| 3 | 5-8 NPT | 141.3 mm |
| 4 | 4-8 NPT | 114.3 mm |
| 5 | G4 | 113.03 mm |
| 6 | R4 | 113.03 mm |
| 7 | 3-1/2-6NH | 107.77 mm |
| 8 | 3-1/2-8 NPT | 101.6 mm |
| 9 | 3-6NH | 92.02 mm |
| 10 | 3-8 NPT | 88.9 mm |
| 11 | 3-8NPSH | 88.14 mm |
| 12 | G3 | 87.884 mm |
| 13 | R3 | 87.884 mm |
| 14 | 2-1/2-7.5NH | 77.94 mm |
| 15 | G2-1/2 | 75.184 mm |
| 16 | R2-1/2 | 75.184 mm |
| 17 | 2-1/2-8 NPT | 73.02 mm |
| 18 | 2-1/2-8NPSH | 72.16 mm |
| 19 | 2" Type A / B (A-A-59326) | 63 mm |
| 20 | 2-11.5 NPT | 60.32 mm |
Questions and answers
Which has the highest major diameter?
The highest major diameter is 6-8 NPT at 168.27 mm.