Thread guide
Find the right nipple for your hydraulic hoses.
There are many different types of threads. The 2 most used are metric and BSP (British Standard Pipe)
It is important to know the correct thread type and size. In this guide you can find out how to
can identify the size and type of your fitting/nipple, coupling or hose.
1. Identify whether the thread is he or she.
This can be easily identified by a visual inspection. Check if the thread is inside the fitting/nipple or outside. If the thread is on the outside, it is a male, and if the thread is on the inside, it is a female.
2. Identify the pitch of the thread.
The pitch of the thread is measured by the number of threads per inch at the BSP and the distance between 2 thread tips if it is a metric thread.
NOTE: We always recommend that you use a thread counter to identify the thread pitch.
3. Identify the thread size
You use a caliper to measure the thread diameter. In the case of an internal thread, it is the internal diameter that must be measured. In the case of an external thread, it is the outer diameter that must be measured.
4. Identify thread types
Now you have gathered the information needed to determine the type of thread. An example might be whether it is either BSP or metric thread.
In the table below you can determine which thread you have on your fitting/nipple, coupling or hose via the above information.
BSP thread
| BSP – Thread Size |
BSP – Bottle tops per inch | Udv. diameter [mm] | Indv. diameter [mm] |
| 1/4″ | 19 | 12,9-13,2 | 11,4-11,9 |
| 3/8″ | 19 | 16,3-16,7 | 14,9-15,4 |
| 1/2″ | 14 | 20,5-21,0 | 18,6-19,0 |
| 3/4″ | 14 | 26,1-26,5 | 24,1-24,5 |
| 1” | 11 | 33,1-33,5 | 30,2-30,8 |
Metric thread
| Metric – Thread Size |
Metric – Distance between 2 threaded peaks [mm] | Diameter measured in [mm] |
| 10L (16×1.5 mm) | 1,0 | 16 ± 0,5 |
| 12L (18×1.5 mm) | 1,5 | 18 ± 0,5 |
| 15L (22×1.5 mm) | 1,5 | 22 ± 0,5 |
| 18L (26×1.5 mm) | 1,5 | 26 ± 0,5 |
