Dimensional stability or brute strength? We break down when and why to choose PA12 or PA6 for your next 3D print.
What Is Nylon 12 (PA12)?
Nylon 12, or PA12, is a high-performance polymer known for its dimensional stability, low moisture absorption, and ease of printing. It features longer molecular chains compared to Nylon 6, which results in less warping and more accurate prints, even without special enclosures or supports.
Nylon 6 vs Nylon 12: Key Differences
- Water Absorption: PA6 can absorb up to 3% of its volume in water. PA12 absorbs only around 0.5%.
- Warping: PA6 warps significantly unless well-dried and enclosed. PA12 prints dimensionally stable parts with fewer headaches.
- Flexibility: PA12 is more flexible; PA6 is more rigid and impact resistant.
- Temperature Resistance: PA6 has a slightly higher usable temperature (~190°C) vs PA12 (~175°C).
- Cost: PA12 is more expensive, but offers reliability for large or long-duration prints.
Real-World Use Case: Automotive Brake Cooling Ducts
PA12 was used to 3D print brake cooling ducts for a Nissan 350Z. These parts didn’t need to withstand high-impact stress but needed dimensional accuracy and heat resistance—making Nylon 12 an ideal candidate. They printed easily, required minimal support, and showed zero warping.
Why McLaren F1 Uses Nylon 12
In Formula 1, adaptability and speed matter. McLaren 3D prints trackside using both PA12 and PA6 for ducting, aero parts, cooling equipment, and tooling. The low warping and high repeatability of PA12 allows for on-demand customization—helping them iterate fast and reduce turnaround time.
When Should You Use Nylon 12?
Choose Nylon 12 when you need:
- Low warping and high dimensional accuracy
- Moisture resistance for long prints or storage
- Flexibility without sacrificing strength
- Better layer adhesion in open or partially enclosed printers
PA6 is still your go-to for high-temperature, impact-prone applications.
Mechanical Testing: Strength, Flexibility, and More
UTM (Universal Testing Machine) tests showed:
- XY-axis strength: ~3200 N average
- Z-axis (layer adhesion): ~1100–1400 N
- Torsion resistance: Consistent break at 9.6 Nm
Flammability Test: Not Fire-Safe
Under direct flame, PA12 burns steadily, drips molten plastic, and emits toxic smoke. It behaves similarly to PETG. For aerospace and cockpit applications, a self-extinguishing material like ULTEM 9085 is preferred.
Conclusion: Nylon 12 is Your Friend for Big, Complex Prints
If you’re printing large, intricate parts, Nylon 12 is a solid choice. It’s more forgiving, prints reliably without warping, and saves time on part failure and retries. While PA6 remains better for rugged, high-heat jobs, Nylon 12 is a superior material for consumer products, automotive parts, and anything requiring tight tolerances.
Need a machine that handles PA12 with ease? Check out the 22 IDEX, a powerhouse printer used to create all test samples in this breakdown.