PA11 vs PA12 is a choice MJF customers often can’t make on their own, and bureau owners argue about it too. In an r/3Dprinting thread, an operator running PA11 on an HP MJF 5200 called it “superior to the standard Nylon 12 in every way,” while another commenter said a customer’s PA11 parts from a 4200 couldn’t pass a drop test. So when is PA11 worth running instead of PA12?
What do HP’s data sheets say?
From HP’s official technical data sheets for HP 3D High Reusability PA 12 and PA 11 (typical values, not for specification):
- Tensile modulus: PA12 1,700 MPa (XY) / 1,800 MPa (Z); PA11 1,800 MPa (XY and Z).
- Elongation at break: PA12 20% (XY) / 15% (Z); PA11 50% (XY) / 35% (Z).
- Notched Izod impact: PA12 3.5 kJ/m²; PA11 5 kJ/m² (XY) / 4.5 kJ/m² (Z).
- Heat deflection at 0.45 MPa: PA12 175°C; PA11 185°C. At 1.82 MPa: PA12 95°C (XY) / 106°C (Z); PA11 54°C.
- Refresh ratio for stable performance: PA12 20%; PA11 30%.
Stiffness is about the same. The big differences are ductility and impact resistance, where PA11 leads, and heat deflection under heavy load, where PA12 leads.
PA11 vs PA12: when should a customer choose PA11?
- Snap fits, clips and living hinges that flex repeatedly.
- Parts that need to absorb impact.
- Programs that track bio-based content. Arkema, which makes PA11, notes it is derived from castor oil.
When is PA12 the better default?
- Parts that see heat while under significant load, given PA12’s higher 1.82 MPa heat deflection.
- Jobs where powder economics matter, since HP rates PA12 for a lower refresh ratio.
- Parts where switching to PA11 for stiffness won’t help, because HP’s modulus figures are nearly identical.
Does PA11 always survive impact testing?
Not necessarily. The drop-test failure in the thread is one operator’s report, but it’s a good reminder: data sheet values come from standard test bars, not your part. Test the real geometry when impact matters.
How do you guide the choice?
Ask what the part does: flexes, carries load, sees heat, or takes impacts. Put a short material guide on your quote page so customers choose before they upload, and price each material from your own powder cost and refresh ratio.
Related on the Solvi blog: MJF vs SLS Parts: What Should a Bureau Tell Customers?; MJF Watertight Parts: Can PA12 Hold Water Under Pressure?.
Sources: HP 3D High Reusability PA 12 data sheet; HP 3D High Reusability PA 11 data sheet; Arkema PA11 vs PA12 article; r/3Dprinting MJF 5200 PA11 thread.