PA11 vs PA12: which nylon powder?
Quick answer
Choose PA11 when the part must bend, snap or survive impact — its datasheet elongation at break is 30–40%, versus 11–18% for PA12. Choose PA12 for general-purpose parts: it is the balanced, widely available, usually cheaper default, with essentially the same tensile strength (48–54 MPa) and stiffness. PA11 is also bio-based (castor oil) and melts about 25 °C higher in EOS's data.
The datasheet comparison
Figures below are the manufacturers' own published values for their flagship grades — full tables and test methods are on each material's page. Cross-brand numbers come from different test standards (ISO 527 for EOS, ASTM D638 for Formlabs), so read them as a consistent picture rather than laboratory rankings.
| Grade | Tensile strength (XY) | Tensile modulus | Elongation at break (XY) |
|---|---|---|---|
| EOS PA 1101 (PA11) | 50 MPa | 1650 MPa | 30% |
| Formlabs Nylon 11 Powder (PA11) | 49 MPa | 1600 MPa | 40% |
| EOS PA 2200 (PA12) | 48 MPa | 1650 MPa | 18% |
| Formlabs Nylon 12 Powder (PA12) | 50 MPa | 1850 MPa | 11% |
| HP HR PA 12 (PA12, MJF) | 54 MPa | 2150 MPa | 18% |
The pattern is stable across three manufacturers: strength and stiffness barely move between the two polymers; elongation roughly doubles or triples with PA11. The Z-direction tells the same story — EOS lists PA 1101 at 15% Z elongation versus 4% for PA 2200, the largest single gap in the table set.
Where the difference comes from
PA11's monomer carries one more methylene unit in its chain than PA12's building blocks, spacing the amide groups slightly further apart. The practical consequences: fewer hydrogen bonds per length, a more flexible chain, lower moisture uptake than PA6-type nylons, and a polymer that yields and stretches instead of cracking. PA11's monomer is produced from castor oil, which is why it is marketed as bio-based. PA12 is fully petrochemical.
Decision rules
- Living hinges, clips, snap-fits, buckles: PA11. These parts are elongation-limited; PA12 will crack early.
- Impact-loaded parts — guards, covers, sports and orthotic components: PA11, for its ductility and non-splintering failure.
- Housings, brackets, ducting, jigs, general production: PA12. Balanced properties, the widest machine/material availability, typically the lowest powder cost.
- Stiffness-critical parts: neither — look at filled grades (glass-filled PA12 at 3200 MPa modulus, or PA6 at 3700 MPa dry) rather than choosing between two ~1650 MPa materials.
- Heat under load: check the specific datasheet, not the polymer name — Formlabs lists PA11 HDT at 1.8 MPa as just 46 °C, while its PA12 reaches 87 °C at the same load.
Cost and availability
PA12 is the volume material of powder-bed printing: every SLS/MJF platform offers it, and service bureaus stock it as the default. PA11 is a qualified second material on major platforms, typically at a price premium, and not every bureau runs it continuously. If a design depends on PA11's ductility, confirm availability with your bureau before committing — or design the part so PA12's elongation suffices.
Frequently asked questions
Is PA11 stronger than PA12?
No — they are in the same strength class (roughly 48-54 MPa tensile across the datasheets on this site). PA11's advantage is ductility and impact resistance: elongation at break of 30-40% versus 11-18% for PA12 grades. Choose by failure mode, not by strength.
Why is PA11 called bio-based?
PA11 is polymerised from a monomer derived from castor oil rather than petroleum. It is still a durable engineering nylon in service — bio-based describes the feedstock, not biodegradability.
Can PA11 and PA12 be printed on the same machine?
Generally yes on open powder systems, with each material's own parameter set — their melting points differ (EOS lists 201 °C for PA 1101 vs 176 °C for PA 2200). Closed systems offer whichever grades the manufacturer has qualified.
Which is better for living hinges?
PA11, clearly. Living hinges live or die on elongation and fatigue behaviour; PA11's 30-40% elongation at break (datasheet) makes it the standard hinge choice in both SLS and MJF.
Sources
Last updated: November 2026