HELIVIQ Industrial · Tools
Hydraulic thread identifier
Measure the thread's outside diameter with a vernier caliper and count the threads per inch with a thread gauge. Enter both to see the closest standard threads.
Reference table
| Family | Designation | Size / dash | OD mm | TPI | Pitch mm |
|---|---|---|---|---|---|
| BSPP | G 1/8 | 1/8" | 9.73 | 28.00 | 0.91 |
| BSPP | G 1/4 | 1/4" | 13.16 | 19.00 | 1.34 |
| BSPP | G 3/8 | 3/8" | 16.66 | 19.00 | 1.34 |
| BSPP | G 1/2 | 1/2" | 20.96 | 14.00 | 1.81 |
| BSPP | G 5/8 | 5/8" | 22.91 | 14.00 | 1.81 |
| BSPP | G 3/4 | 3/4" | 26.44 | 14.00 | 1.81 |
| BSPP | G 1 | 1" | 33.25 | 11.00 | 2.31 |
| BSPP | G 1-1/4 | 1-1/4" | 41.91 | 11.00 | 2.31 |
| BSPP | G 1-1/2 | 1-1/2" | 47.80 | 11.00 | 2.31 |
| BSPP | G 2 | 2" | 59.61 | 11.00 | 2.31 |
| NPT | 1/8 NPT | 1/8" | 10.29 | 27.00 | 0.94 |
| NPT | 1/4 NPT | 1/4" | 13.72 | 18.00 | 1.41 |
| NPT | 3/8 NPT | 3/8" | 17.15 | 18.00 | 1.41 |
| NPT | 1/2 NPT | 1/2" | 21.34 | 14.00 | 1.81 |
| NPT | 3/4 NPT | 3/4" | 26.67 | 14.00 | 1.81 |
| NPT | 1 NPT | 1" | 33.40 | 11.50 | 2.21 |
| NPT | 1-1/4 NPT | 1-1/4" | 42.16 | 11.50 | 2.21 |
| NPT | 1-1/2 NPT | 1-1/2" | 48.26 | 11.50 | 2.21 |
| NPT | 2 NPT | 2" | 60.33 | 11.50 | 2.21 |
| JIC | 7/16-20 UNF | -4 | 11.11 | 20.00 | 1.27 |
| JIC | 1/2-20 UNF | -5 | 12.70 | 20.00 | 1.27 |
| JIC | 9/16-18 UNF | -6 | 14.29 | 18.00 | 1.41 |
| JIC | 3/4-16 UNF | -8 | 19.05 | 16.00 | 1.59 |
| JIC | 7/8-14 UNF | -10 | 22.23 | 14.00 | 1.81 |
| JIC | 1-1/16-12 UNF | -12 | 26.99 | 12.00 | 2.12 |
| JIC | 1-3/16-12 UNF | -14 | 30.16 | 12.00 | 2.12 |
| JIC | 1-5/16-12 UNF | -16 | 33.34 | 12.00 | 2.12 |
| JIC | 1-5/8-12 UNF | -20 | 41.28 | 12.00 | 2.12 |
| JIC | 1-7/8-12 UNF | -24 | 47.63 | 12.00 | 2.12 |
| JIC | 2-1/2-12 UNF | -32 | 63.50 | 12.00 | 2.12 |
| ORFS | 9/16-18 UN | -4 | 14.29 | 18.00 | 1.41 |
| ORFS | 11/16-16 UN | -6 | 17.46 | 16.00 | 1.59 |
| ORFS | 13/16-16 UN | -8 | 20.64 | 16.00 | 1.59 |
| ORFS | 1-14 UN | -10 | 25.40 | 14.00 | 1.81 |
| ORFS | 1-3/16-12 UN | -12 | 30.16 | 12.00 | 2.12 |
| ORFS | 1-7/16-12 UN | -16 | 36.51 | 12.00 | 2.12 |
| ORFS | 1-11/16-12 UN | -20 | 42.86 | 12.00 | 2.12 |
| ORFS | 2-12 UN | -24 | 50.80 | 12.00 | 2.12 |
| METRIC | M12x1.5 | M12x1.5 | 12.00 | 16.93 | 1.50 |
| METRIC | M14x1.5 | M14x1.5 | 14.00 | 16.93 | 1.50 |
| METRIC | M16x1.5 | M16x1.5 | 16.00 | 16.93 | 1.50 |
| METRIC | M18x1.5 | M18x1.5 | 18.00 | 16.93 | 1.50 |
| METRIC | M20x1.5 | M20x1.5 | 20.00 | 16.93 | 1.50 |
| METRIC | M22x1.5 | M22x1.5 | 22.00 | 16.93 | 1.50 |
| METRIC | M24x1.5 | M24x1.5 | 24.00 | 16.93 | 1.50 |
| METRIC | M26x1.5 | M26x1.5 | 26.00 | 16.93 | 1.50 |
| METRIC | M30x2 | M30x2 | 30.00 | 12.70 | 2.00 |
| METRIC | M36x2 | M36x2 | 36.00 | 12.70 | 2.00 |
| METRIC | M42x2 | M42x2 | 42.00 | 12.70 | 2.00 |
| METRIC | M45x2 | M45x2 | 45.00 | 12.70 | 2.00 |
| METRIC | M52x2 | M52x2 | 52.00 | 12.70 | 2.00 |
Reference values for identification only. Confirm critical connections against the manufacturer's data before fitting.
Hose dash sizes
Hose dash sizes
| Dash | Inch ID | mm ID | DN |
|---|---|---|---|
| -4 | 1/4" | 6.4 | DN6 |
| -5 | 5/16" | 7.9 | DN8 |
| -6 | 3/8" | 9.5 | DN10 |
| -8 | 1/2" | 12.7 | DN12 |
| -10 | 5/8" | 15.9 | DN16 |
| -12 | 3/4" | 19.1 | DN19 |
| -16 | 1" | 25.4 | DN25 |
| -20 | 1-1/4" | 31.8 | DN31 |
| -24 | 1-1/2" | 38.1 | DN38 |
| -32 | 2" | 50.8 | DN51 |
Questions buyers ask
Questions buyers ask
How do I measure a hydraulic thread?
Measure the outside diameter across the thread crests with a vernier caliper, then use a thread pitch gauge to count threads per inch or read the pitch in millimetres. For female threads, measure the inside diameter and compare it with the male size it accepts.
How can I tell BSP from NPT?
NPT threads are tapered, so the diameter changes along the length and the thread angle is 60°. BSPP is parallel with a 55° angle. Some sizes share the same threads per inch, so check for taper and the seal type as well.
What does a hose dash size mean?
The dash number is the hose inside diameter in sixteenths of an inch. A -8 hose has a 8/16, or 1/2 inch, inside diameter.
Next step
Send the thread, get the part
Share your measurements or a photo with a ruler. We identify the connection and quote the matching item.