PPA
A semi-aromatic polyamide for heat
Typical values for the temper in the title
PPA is a semi-aromatic polyamide: aromatic rings in the chain raise the melting point (about 310–325 °C by grade) and thermal stability, and lower water absorption compared with ordinary polyamides such as PA66.
It is almost always glass-fiber filled, and is used for hot automotive parts (cooling, fuel and engine systems), connectors and electronic components that undergo soldering, and pump housings. In ASTM it is classified per D5336.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Max continuous service temperature | ≈150–180°C | |
| Machinability | 60% | relative rating in the site database |
Structure and family
| Feature | Value | Meaning |
|---|---|---|
| Family | semi-aromatic polyamide | |
| Tm | about 310–325 °C | by grade |
| Water absorption | lower than PA66 | dimensional stability |
Typical values per producer data sheets.
Grades and versions
In engineering polymers, the choice is between an unfilled grade, filled grades (glass or carbon fiber) and special grades (bearing, medical, food). Filler strongly changes strength, stiffness and expansion.
| Version | Properties | When to choose it |
|---|---|---|
| GF30 / GF45 | stiff and strong | hot structural parts |
| Electrical grade | flame retardant | connectors |
Applications
- Cooling and fuel system parts
- Engine parts
- Electrical connectors
- Pump housings
- Solderable components
Fabrication
Machining
Use very sharp tools, a feed that does not overheat the material, and good support (the material is flexible and deforms under clamping). For precision parts, stress-relief annealing before final machining is sometimes performed.
Thermal expansion
The expansion coefficient of an unfilled polymer is several times that of a metal. In a precision part or an assembly with metal, design clearances accordingly.
Molding
Requires a high mold temperature to fully crystallize the material.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| PA66 (Nylon 66) | 70-85 MPa | Ultrasonic | PA66: cheaper, absorbs more water · material page |
| PA46 | — | Ultrasonic / hot plate | PA46: low friction, absorbs water · material page |
| PPS | 165 MPa | Ultrasonic | PPS: more chemically resistant · material page |
Common mistakes
Molding in a cold mold
Crystallization is incomplete, and properties suffer.
Expecting unfilled properties
Most grades are filled, and properties are directional.
Ignoring water absorption
It is lower than PA66, but present.
Equivalents, standards and supply
| ISO | PPA |
|---|---|
| ASTM | D5336 |
| Standards | ASTM D5336 |
| Forms | sheet · rod · pellets |
| Producers | Solvay (Amodel) · EMS (Grivory HT) |
Learn more
Values are typical for an unfilled grade (unless stated otherwise) and for comparison only. In polymers, properties depend on grade, filler, temperature, moisture and load duration. For design, rely on the producer data sheet for the specific grade. Sources: ASTM classification standards (D8033, D5205, D5204, D6394, D4067 and others), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026