PA 11 vs PA 12: A Practical Guide to Choosing the Right Nylon

Choosing between PA 11 and PA 12 is one of the more common questions we hear from customers working with SLS. Both materials are nylon. Both work beautifully with SLS. And at a chemical level, they differ by a single carbon atom. Yet that one atom changes quite a lot about how the finished part behaves, which matters when you’re choosing a material for a functional application.

Here’s what you need to know.

The Basics: What Are PA 11 and PA 12?

PA 11 and PA 12 are both polyamides, the family of materials most people know as nylon. The number refers to how many carbon atoms sit in the monomer chain. PA 11 has eleven; PA 12 has twelve.

The chemistry sounds trivial, but it affects how the polymer chains pack together, and that changes the mechanical behaviour of the finished part.

There’s another notable difference in how the two materials are made. PA 12 is derived from petroleum. PA 11, by contrast, is a bio-based material produced from castor oil, which gives it a notably lower environmental footprint. In fact, PA 11 is one of the few engineering-grade thermoplastics with a genuinely renewable origin.

Both materials are available in powder form and are well suited to powder bed fusion processes like SLS and MJF.

Where PA 11 Has the Edge

• Flexibility and Impact Resistance – PA 11 is significantly more ductile than PA 12. It stretches further before breaking and absorbs more energy under impact. If a part needs to flex, bend, or take a knock without snapping, PA 11 is the stronger choice. This is why PA 11 is the material people reach for when designing living hinges, snap-fit clips, buckles, and other features that depend on repeated elastic deformation. With high elongation at break as its standout property, our EOS PA 11 is specifically recommended for these applications.
• Thinner Walls, Less Material – Because PA 11 is more ductile, it can hold its integrity at thinner wall sections than PA 12. For complex lattice structures or fine-walled ductwork, that flexibility is a genuine advantage.
• Surface Finish – PA 11 generally produces a slightly smoother as-printed surface than PA 12. In applications where aesthetics or surface friction are important, this can be a relevant consideration.
• Sustainability – If environmental credentials are part of your material selection criteria, PA 11 is the better option. Its bio-based origin means lower embodied carbon compared to petroleum-derived PA 12.

Where PA 12 Has the Edge

• Stiffness and Dimensional Stability – PA 12 is stiffer. It resists deformation under load and maintains its shape reliably over time. For parts that need to hold tight tolerances or carry consistent structural loads in service, this rigidity is an advantage rather than a limitation.
• Heat and Chemical Resistance – PA 12 performs better at elevated temperatures and holds up well against a broader range of aggressive chemicals, including oils, hydraulic fluids, fuels, and solvents. Where regular exposure to these substances is expected, PA 12 is the more dependable choice.
• Low-Temperature Performance – PA 12 also maintains its mechanical properties further below freezing than PA 11. Sub-zero conditions are where PA 12 earns its reputation, making it the safer selection for outdoor or cold-environment applications.
• Noise and Vibration Damping – A less-discussed property: PA 12 is a good damper of noise and vibration. In assemblies where components are in contact and movement or rattling is a concern, this characteristic can be genuinely useful.

The Practical Guide: Which One Do You Need?

What Formero Offers

EOS PA 11 is our bio-based PA 11 option. It offers outstanding toughness, excellent impact resistance, and high elongation at break. It is the right choice for functional parts that need to flex or absorb impact. The white colour and smooth surface make it a good candidate for visible or aesthetic parts too.

DuraForm PA 12 is our primary PA 12 material and the most commonly used SLS material we offer. It suits a wide range of functional prototypes and low-to-mid volume production parts where rigidity, heat resistance, and consistent mechanical performance are needed.

HP PA 12 (MJF) is our Multi Jet Fusion option for PA 12. It delivers the same core material properties with a smoother surface finish straight off the machine and consistent mechanical performance in all directions.

Ordering PA Parts from Formero

There is one operational difference between the two materials that is worth knowing. SLS PA 12 parts are processed on a large-format SLS printer set up exclusively for that material. Because it processes PA 12 orders continuously, turnaround times are typically faster and the cost per part is slightly lower.

PA 11 and our other SLS materials are processed on two separate printers, with builds scheduled as orders accumulate. That means PA 11 parts generally carry a slightly longer lead time than an equivalent PA 12 order. For most projects that is not a problem, but if a deadline is tight, it is a useful factor to weigh alongside the material properties themselves.

Still Not Sure Which Material Is Right for Your Application?

We’ve helped customers work through this decision many times, and often the right answer isn’t obvious from a spec sheet alone. If you’d like to talk it through with someone from our team, get in touch at sales@formero.com.au, call +61 3 8899 7280 or complete the form below.

3D Printing, Knowledge Hub