PA12 (Nylon 12)
A low-water-absorption polyamide
Typical values for the temper in the title
PA12 (nylon 12) is a polyamide with much lower water absorption than PA6 and PA66, so it is more dimensionally stable, and flexible and tough even when cold. It is resistant to oils, fuels and abrasion.
It is used for automotive fuel and air lines, pneumatic tubing, cable insulation, and it is also the most common material in plastic printing by laser sintering (SLS) and MJF.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 50 MPa | |
| Elongation A | 200% | |
| Modulus of elasticity E | 1.4 GPa | |
| Density ρ | 1.02 g/cm³ | |
| Rockwell hardness | R105 | |
| Machinability | 70% | relative rating in the site database |
Structure and family
| Feature | Value | Meaning |
|---|---|---|
| Type | semi-crystalline polyamide | strength and toughness |
| Tm melting | about 178 °C | |
| Water absorption | much lower than PA6 and PA66 | affects dimensions and properties |
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 |
|---|---|---|
| Unfilled | flexible and tough | tubing and parts |
| Printing powder (SLS / MJF) | strong printed parts | prototypes and low-volume production |
| Glass-fiber filled | stiffer | structural parts |
Applications
- Automotive fuel and air lines
- Pneumatic tubing
- Cable insulation
- Printed parts (SLS / MJF)
- Flexible fittings
Fabrication
Water absorption
Polyamides absorb water from the air. Water plasticizes the material, reduces strength and stiffness and increases dimensions. For a precision part, design to the conditioned state, not the dry state.
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.
Joining
Ultrasonic, hot-plate or vibration welding, and mechanical assembly.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| PA6 (Nylon 6) | 75–80 MPa | Ultrasonic | PA6: stronger and stiffer, absorbs water · material page |
| TPU | 25-55 MPa | Ultrasonic / Hot Gas | TPU: more flexible, an elastomer · material page |
| POM (Acetal) | 70 MPa | Ultrasonic | POM: stiff and stable · material page |
Common mistakes
Designing to dry-state properties
Conditioned, strength and stiffness are lower. Design to conditioned data.
Ignoring dimensional change
The part grows slightly as it absorbs water.
Expecting PA6 stiffness
PA12 is more flexible (database modulus about 1.4 GPa).
Equivalents, standards and supply
| ASTM | D6779 |
|---|---|
| Standards | ASTM D6779 |
| Forms | rod · pipe · SLS Print |
| Producers | Evonik Vestamid · Arkema |
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