The vast majority of SLS parts are printed in nylon, and two grades dominate the field above all others: PA12 and PA11. Both are tough, versatile engineering plastics that perform far better than the everyday materials people associate with hobby 3D printing, and both produce parts you can genuinely put to work. They do, however, have distinct strengths that make each one better suited to particular kinds of job.
Choosing the right nylon up front means the finished part behaves exactly as you expect once it is in service, rather than surprising you later. Our team can guide the choice for you as part of a MJF & SLS printing quote, but it genuinely helps to understand the basics so you can describe what your part has to do, how hard it will be worked and where it will live.
PA12, the reliable all rounder
PA12 is the most common SLS material by a wide margin, and for good reason. It is strong, dimensionally stable and resistant to moisture and many chemicals, which together make it a dependable choice for housings, brackets, clips, enclosures and general functional parts. If you are not sure what to specify, PA12 is almost always a safe and sensible starting point that will not let you down.
A key advantage is that PA12 absorbs very little water, so it holds its size and shape well over time even in humid conditions. That stability is one of the main reasons it has become the default nylon for both prototypes and production parts, because a part you measure today will still measure the same in a month. It also takes a clean dye and a smooth seal well, so it presents nicely when appearance counts.
PA11, the tougher cousin
PA11 is derived from renewable castor oil and offers noticeably higher impact strength and greater flexibility than PA12. That extra toughness makes it the better choice for parts that have to flex, absorb shocks or survive repeated drops without cracking, where the stiffer PA12 might eventually fail. It is the nylon to reach for when resilience matters more than outright rigidity.
Typical applications include living hinges, snap fits, sporting goods, wearables and protective components. PA11 trades a small amount of stiffness for a large gain in ductility, and the fact that it comes from a renewable source is a welcome bonus for customers thinking about the environmental footprint of their parts. It costs a little more than PA12, so we usually specify it only where the extra toughness earns its place.
Filled and specialist grades
Beyond the two standard nylons, filled grades widen the range further. Glass filled nylon adds stiffness and heat resistance for parts that must hold their shape under load or near warm components, at the cost of a little toughness and a heavier part. Aluminium filled and carbon loaded grades exist for specific stiffness and appearance needs, though they are less commonly required for everyday work.
These specialist powders suit brackets, fixtures and jigs that have to resist deflection rather than flex. If you think your part needs more than a standard nylon can give, describe the loads and temperatures it will see and we will tell you whether a filled grade is worth it for your job.
Matching material to use
The right nylon really comes down to what the part has to endure in service, so it pays to think about the loads it will carry, the impacts it might take and the environment it will live in before printing. Tell us those details and we will steer you to the grade that fits.
- Choose PA12 for stable, accurate housings and general functional parts.
- Choose PA11 for high impact, flexing or shock loaded components.
- Both resist moisture far better than typical filament nylons.
- Glass filled grades are available where extra stiffness is required.
- PA11 comes from a renewable castor oil source.