High-pressure plastic tubing: the short answer
For plastic tubing, working pressure is set by three things together: the material, the outer diameter and the wall thickness. In our PA6, PA12 and composite ranges the highest listed working pressure is 41 bar, on the smallest PA6 size (YN-PA6 0425, 4 mm OD × 2.5 mm ID). The same size in PA12 is rated 29 bar and in high-pressure composite tubing 16 bar. Pressure generally falls as the outer diameter grows and as the wall gets thinner.
The composite tube is built for flexibility with a PU or polyether TPU outer layer over a PA12 inner layer, so choose it for bend radius, not for the highest pressure. Pick the size from the table below, then confirm temperature, fittings and medium before you order.
Working pressure by size: PA6, PA12 and composite
The table lines up tubes with the same outer and inner diameter, taken from the data sheets of our PA6 nylon tubing, PA12 nylon tubing and high-pressure composite tubing. Pressures are working pressure in bar at 23 °C. The two composite constructions (V8 with a PU outer layer, V9 with a polyether TPU outer layer) list the same working pressure at these sizes.
| OD × ID (mm) | PA6 (bar) | PA12 (bar) | Composite V8 / V9 (bar) |
|---|---|---|---|
| 4 × 2.5 | 41 | 29 | 16 |
| 6 × 4 | 35 | 27 | 14 |
| 8 × 5 | 28 | 29 | 15 |
| 8 × 6 | 23 | 17 | 12 |
| 10 × 6.5 | 31 | 24 | 19 |
| 10 × 8 | 18 | 14 | 12 |
| 12 × 8 | 22 | 16 | 17 |
| 16 × 12 | 22 | 14 | 15 |
Three patterns are worth reading from the table. PA6 carries the highest working pressure at nearly every size. PA12 matches or passes PA6 only at 8 × 5. And the composite tube passes PA12 at 12 × 8 and 16 × 12, and it keeps a much tighter bend radius than either nylon at those sizes.
Wall thickness matters as much as material
At a fixed outer diameter, a thicker wall (smaller inner diameter) carries more pressure. For 8 mm OD tubing the data sheets list:
| 8 mm OD size | Wall (mm) | PA6 (bar) | PA12 (bar) | Composite (bar) |
|---|---|---|---|---|
| 8 × 5 | 1.5 | 28 | 29 | 15 |
| 8 × 5.5 | 1.25 | 28 | 19 | 12 |
| 8 × 6 | 1.0 | 23 | 17 | 12 |
The tubing at 8 × 5 and 8 × 6 has the same outside diameter and fits the same push-in fitting, yet the rated pressure differs. When a line needs more pressure, move to a thicker wall at the same OD before you change material. Our guide to matching tubing to fittings explains why the OD is the dimension that has to match.
How to choose a high-pressure tube, step by step
- Set the maximum working pressure of the line, including peaks from valves and pumps, and compare it with the working pressure in the table, not the burst pressure.
- Check the temperature. The ratings above are at 23 °C. Pressure capacity drops as the tube warms; see the pressure and temperature guide for the derating factors.
- Choose the OD for your fittings, then the wall for your pressure. Use the tubing size chart to find every size and wall we list.
- Check the bend radius. A stiff, high-pressure wall needs a larger radius; see the bend radius guide. Composite tubing bends tighter than PA6 at the same size.
- Match the medium. Nylon and polyurethane handle different fluids; the chemical resistance guide shows the published ratings.
- Confirm the size on the data sheet for your model before ordering.
PA6, PA12 or composite: which fits which job
- PA6 is the choice when pressure is the priority and routing is simple. It has the highest rating in the table and a larger bend radius. See the PA6 vs PA12 comparison.
- PA12 is generally the more flexible of the two and is used where routing and flexing matter as well as pressure; compare the bend radius for your size.
- Composite (PU or polyether TPU over PA12) suits moving machinery where the tube has to bend tightly, with pressure ratings in the 12–19 bar range across the metric sizes.
Plastic tubing covers the pressures in the table. Lines that run well above them, such as hydraulic and ultra-high-pressure systems, are specified in metal tubing or reinforced hose.
Applications
For the application view, see high-pressure equipment tubing and the pneumatic tubing guide.
Frequently asked questions
What is the highest working pressure you list for plastic tubing?
Among PA6, PA12 and composite tubing, the highest listed working pressure is 41 bar, for YN-PA6 0425 (4 mm OD × 2.5 mm ID) at 23 °C. Every size and its rating is on the product page.
Is PA12 or PA6 better for high pressure?
At most sizes PA6 is rated higher. PA12 is generally the more flexible of the two, so it is chosen when the line has to bend as well as hold pressure. Compare your exact OD and wall in the table above.
Is composite tubing the high-pressure option?
It is the flexible option. Its working pressure sits between 12 and 19 bar across the metric sizes, lower than PA6 at small sizes and close to PA12 at larger ones. Choose it for tight bends and moving machinery.
Does a thicker wall increase the pressure rating?
Yes. At the same outer diameter, a smaller inner diameter gives a thicker wall and a higher rating. For 8 mm OD PA12 the listed working pressure is 29 bar at 8 × 5 and 17 bar at 8 × 6.
Do the pressures change with temperature?
Yes. The values here are working pressures at 23 °C. Use the derating factors in the pressure and temperature guide for warmer lines.
Confirm your specification
Send the working pressure, temperature, medium, dimensions and fitting details, and we will check them against the data sheet of the matching tubing. Send your requirements or browse the full product range.
Sources and scope
- PA6 Nylon Tubing — English data sheet (v4-20261020)
- PA12 Nylon Tubing — English data sheet (v5-20261020)
- High-Pressure Composite Tubing — English data sheet (20261020)
Use these documents for the identified product models and stated test conditions. General material comparisons and selection checklists do not establish a different grade’s rating, fitting compatibility or project approval. Confirm the exact model, medium, temperature, pressure and required evidence before ordering.
Content review: zhangkexin · Marketing
Review scope: market information and document references.
