PPA Tube — IDs, ODs, Wall Thicknesses & Lengths
PPA tube is hollow extruded stock produced from Polyphthalamide (PPA). As the high-performance member of the nylon family available from Ready Plastics, PPA tube provides elevated thermal resistance, high stiffness, and excellent dimensional stability compared to PA6, PA66, or PA12 tube. It is specified for sleeve bearings, wear liners, and precision cylindrical components in hot, chemically demanding, or high-load operating environments where standard nylon tube grades would be inadequate.
At a glance:
- OD range: 0.5" to 4.0" (common stocked sizes)
- Wall thickness: typically 0.125" to 0.500"
- Standard lengths: 4 ft
- ID tolerance: ±0.010" (typical)
- Material: Polyphthalamide (PPA) — extruded
- Color: Natural (off-white/light tan)
Standard Size Table
PPA tube is stocked in precision sizes for high-performance machined applications:
| OD | ID | Wall | Standard Length | Notes |
|---|---|---|---|---|
| 0.75" | 0.375" | 0.188" | 4 ft | Precision high-temp bushings |
| 1.00" | 0.50" | 0.25" | 4 ft | High-performance sleeve bearings |
| 1.50" | 0.875" | 0.313" | 4 ft | Thermal-resistant bearing liners |
| 2.00" | 1.25" | 0.375" | 4 ft | Medium-bore sleeves in hot environments |
| 2.50" | 1.75" | 0.375" | 4 ft | Fluid-handling and industrial sleeves |
| 3.00" | 2.25" | 0.375" | 4 ft | Large-bore high-temperature liners |
| 4.00" | 3.00" | 0.50" | 4 ft | Maximum stocked OD |
Custom OD/ID combinations and cut-to-length service are available from Ready Plastics.
Mechanical & Thermal Properties
PPA tube provides a meaningful performance upgrade over standard nylon tube grades:
| Property | Notes |
|---|---|
| Tensile strength | High — superior to PA6, PA66, PA12 tube |
| Stiffness | High modulus — resists bore deformation under radial loading better than standard nylons |
| Heat resistance | Elevated continuous service temperature — operates where PA66 begins to soften |
| Dimensional stability | Excellent — low moisture absorption maintains bore dimensions |
| Chemical resistance | Resists oils, fuels, and many industrial process fluids |
| Flammability (UL 94) | HB |
Full numeric specifications are available in the PPA material datasheet.
For comparison: PA66 tube serves well at moderate temperatures; PPA tube is the correct choice where continuous high-temperature operation, greater stiffness, or more demanding chemical exposure is involved.
Typical Applications
PPA tube is used for the highest-demand sleeve and liner applications in the nylon family:
- High-temperature sleeve bearings — operates reliably in environments that would deform or soften PA66 bearings
- Under-hood automotive bearing components — thermal and chemical resistance suits proximity to hot fluids and surfaces
- Fluid handling pump sleeves — chemical resistance and thermal stability in process pump components
- Precision electrical insulating sleeves — dielectric properties plus thermal resistance for electrical assemblies
- High-load wear liners — high stiffness reduces elastic deformation under radial loading vs. standard nylons
Machining PPA Tube
PPA tube machines cleanly on a lathe with sharp carbide tooling. Its higher hardness requires controlled feed rates for fine bore and OD finishes — avoid aggressive cuts that can introduce heat at the cutting edge. Low moisture absorption means bore dimensions after machining closely reflect in-service dimensions; interference fit calculations are more predictable than with PA6 or PA66 tube. Parting and cutting to length with a bandsaw produces clean, consistent cuts.
Related
- PPA Material Line Card
- PPA Rod — solid bar for high-temperature precision machined components
- PPA Sheet — flat plate for high-temperature structural panels and wear pads