If you have ever put a drawing out to quote and got back one supplier calling the material nylon and another calling it polyamide, the short version is that they were both quoting the same thing. Polyamide vs nylon is a naming question, not a materials question. The confusion is worth clearing up anyway, because the number that follows the name is where the real engineering differences hide, and that is the part people skip.
Below: why the two names exist, what the digits in PA6, PA11, PA12 and PA66 actually count, how the common grades differ in practice, and where laser sintered PA12 sits with real datasheet numbers attached.
Polyamide vs Nylon: The Short Answer
Polyamide and nylon are the same class of material. A polyamide is any polymer whose repeating units are joined by amide links, and nylon is the name one of those polymer families picked up commercially and never lost. If a datasheet says PA12 and a purchase order says nylon 12, nothing has changed except the vocabulary.
Which word you hear mostly tells you who is talking. Engineering datasheets, ISO standards and European suppliers use polyamide and the PA abbreviation. North American shop floors and purchasing systems tend to say nylon. Textile and apparel labelling uses polyamide almost exclusively, which is why the same word shows up on a jacket tag and on an industrial powder specification.
In an industrial materials context that distinction almost never surfaces. When a supplier, a datasheet or a purchase order says polyamide, they mean the aliphatic nylon grades, and PA12 and nylon 12 are the same powder either way. The wider definition matters in a chemistry lecture. It does not change what arrives on your dock.
Why Two Names Exist at All
Nylon began as a trade name from DuPont and slipped into generic use so thoroughly that it stopped functioning as a brand. Polyamide is simply the accurate chemical description, and it stayed in the technical literature while nylon took over everyday speech.
The practical consequence is that polyamide is the more precise term and nylon is the more common one. Standards bodies went with precision. The designation system for these materials is defined in ISO 16396-1, which sets out how a polyamide moulding or extrusion material is written down, including the grade identifier and the property values used to specify it. No equivalent standard governs the word nylon, which is a fair summary of the difference in status between the two terms.
What Is Polyamide, and What Is Nylon Made Of?
A polyamide is a polymer whose repeating units are joined by amide links, the same bond chemistry that holds proteins together. That single structural feature is what gives every grade in the family its shared character: toughness, wear resistance, and a tolerance for oils and fuels that most commodity plastics do not have.
As for what nylon is made of, the answer for most grades is petrochemical feedstock. Monomers are synthesised, polymerised into long chains, then pelletised for moulding or ground and classified into powder for sintering. PA11 is the notable exception, since its monomer is derived from castor oil, which is why it turns up in specifications where a bio-based content figure has to be reported.
Polyamide as a material is semi-crystalline rather than fully amorphous, meaning the chains pack into ordered regions separated by disordered ones. The ordered regions carry load and resist wear, the disordered regions absorb impact, and the balance between them is what a powder supplier tunes when developing a grade. It is also why polyamide melts over a range rather than at a single sharp temperature, a detail that turns out to decide which grades can be laser sintered at all.
The one weakness worth naming up front is water. Amide links attract it, and absorbed water plasticises the polymer, which means a nylon material can lose stiffness and grow slightly in a humid environment. How much depends entirely on the grade, and that is the difference the naming digits encode.
What the Numbers After PA Actually Mean
The digits count carbon atoms in the monomers the polymer was built from. A single number means the chain was made from one monomer, and the number is how many carbons that monomer contributes. Two numbers mean two monomers, a diamine and a diacid, and each digit counts the carbons in one of them.
That is the whole convention, and once you know it the naming stops being arbitrary. PA6 comes from a single six carbon unit. PA12 comes from a single twelve carbon unit. PA66 comes from a diamine and a diacid that each carry six carbons, which is why it is written as two sixes and not as twelve.
| Designation | Also written as | Built from |
|---|---|---|
| PA6 | Nylon 6 | One monomer contributing six carbon atoms |
| PA11 | Nylon 11 | One monomer contributing eleven carbon atoms |
| PA12 | Nylon 12 | One monomer contributing twelve carbon atoms |
| PA66 | Nylon 6,6 or nylon 66 | Two monomers, each contributing six carbon atoms |
Longer carbon spacing between amide links means fewer of those links per unit of chain length. Amide links are the sites that attract water, so the trend that matters for engineers falls straight out of the naming: the higher the number on a single monomer grade, the less moisture the material tends to take up, and the more dimensionally settled a finished part tends to stay.
The Polyamide Grades You Will Actually Meet
Four grades cover the overwhelming majority of industrial work: PA6, PA66, PA11 and PA12. They split cleanly into two camps. PA6 and PA66 are the high strength, moisture hungry pair that dominate injection moulding. PA11 and PA12 are the dimensionally stable pair that dominate powder bed fusion.
The table below is an orientation map rather than a specification. Each of these pairings deserves its own head to head, and the honest summary is that grade selection is usually decided by moisture, temperature and process rather than by headline tensile numbers.
| Grade | Where you meet it | Moisture behaviour | The trade-off |
|---|---|---|---|
| PA6 | Injection moulded and extruded parts, textiles, bearings and bushings | Absorbs readily | Strong and tough when dry, but strength and dimensions shift as it takes up humidity |
| PA66 | Under-hood automotive parts, electrical housings, high load mouldings | Absorbs readily | Higher stiffness and heat capability than PA6, harder to process and still humidity sensitive |
| PA11 | Fuel and air lines, and as an SLS powder where impact matters | Low | Tougher and more impact tolerant than PA12, and it costs more |
| PA12 | The default powder for industrial laser sintering, plus tubing and moulded parts | Low | Excellent dimensional stability and printability, with moderate stiffness rather than high |
| Filled polyamides | Glass filled, mineral filled and aluminium filled variants of the above | Depends on the base grade | Stiffness and heat resistance go up, ductility and impact tolerance come down |
Where PA12 Sits, and Why Sintering Settled On It
PA12 is the polyamide grade that industrial laser sintering standardised on, and the reason is process behaviour rather than raw strength. It has a wide enough gap between melting and recrystallisation for a powder bed to stay stable through a long build, it takes up very little moisture, and unfused powder survives well enough to be reclaimed and reused across builds.
None of that makes PA12 the strongest polyamide. PA66 will out-stiffen it and PA11 will out-toughen it. What PA12 offers is a combination that holds together in production: parts that come off the machine close to nominal, stay close to nominal in a humid plant, and behave the same way in the tenth build as in the first. For a full treatment of the material itself, our PA12 nylon material guide goes deeper on chemical resistance, finishing and design allowances than this comparison needs to.
Attempts to sinter PA6 and PA66 exist, but the process window is narrow and the results are far less forgiving, which is why they remain moulding materials in practice. If you are choosing between powders rather than between polyamides in general, our guide on how to choose SLS materials lays out the options side by side.
Laser Sintered PA12: The Actual Numbers
Published values for a laser sintering polyamide come from the powder supplier, measured on standard test specimens under named ISO methods. The figures below are for EOS PA 2200, the PA12 powder used across industrial sintering, taken from the EOS PA 2200 material data sheet.
| Property | Value | Test method |
|---|---|---|
| Tensile strength | 48 MPa | EN ISO 527 |
| Tensile modulus | 1700 MPa | EN ISO 527 |
| Elongation at break | 24 percent | EN ISO 527 |
| Flexural modulus | 1500 MPa | EN ISO 178 |
| Shore D hardness | 75 | ISO 868 |
| Density of laser sintered part | 0.93 g per cubic cm | EOS method |
| Melting point | 172 to 180 C | EN ISO 11357-1 |
| Vicat softening temperature B/50 | 163 C | EN ISO 306 |
Read that table with two caveats, because engineers get burned by both. The first is that these are values for one specific powder, not for polyamide as a category and not for every PA12 powder on the market. The second matters more: datasheet numbers come from test bars built and measured under controlled conditions, and your part is not a test bar. Wall thickness, build orientation, position in the build volume and powder refresh history all move real results away from the published figure, and orientation is usually the biggest single factor. Treat the table as the material ceiling and design with margin below it.
Does the Naming Difference Change What You Specify?
No, and that is exactly why the naming matters. Because polyamide and nylon are interchangeable words, neither one tells a supplier anything useful on its own, and a specification that stops at either word has not specified a material.
We are Anubis 3D Industrial Solutions. We manufacture end-of-arm tooling and produce parts by selective laser sintering at our facility in Mississauga, Ontario, and drawings arrive with material called out as nylon far more often than as PA12. When they do, the questions that actually resolve the spec are the same three every time: which grade, filled or unfilled, and by which process. A part called nylon and moulded in PA66 and the same part called polyamide and sintered in PA12 will behave differently in service, and the difference has nothing to do with the noun on the drawing.
If the material line on your print says nylon with no number, treat that as an open question rather than a decision. Our EOAT glossary defines the process and material terms that usually need pinning down alongside it.
Polyamide in Robotic Tooling: Why the Grade Decides
For robot tooling, the polyamide question is settled by dimensional stability rather than by peak strength. A gripper that holds tolerance on a dry morning and drifts by the afternoon is worse than a slightly less stiff one that never moves, which is what pushes tooling toward PA12 and away from the moisture sensitive grades.
Weight is the other reason. Sintered polyamide lets a tool carry its air channels internally and shed the mass a machined metal equivalent would need, which returns payload and acceleration headroom to the robot. That trade is the basis of most of the end-of-arm tooling we design and print, and one worked example is our carton extracting tool, where a metal assembly was replaced with a nylon 12 build.
Filled grades enter the conversation when a wear face or a stiffness target demands them, and they bring brittleness with them. That is a per feature decision rather than a per tool one, and it is usually better solved by adding a wear insert than by changing the whole material.
Polyamide and Nylon Questions
Is polyamide the same as nylon?
Yes. Polyamide is the chemical family name and nylon is the commercial name that entered general use for the same materials. A datasheet reading PA12 and a purchase order reading nylon 12 describe the same polymer.
What does the number in PA12 or nylon 66 mean?
It counts carbon atoms in the monomers. A single number means one monomer contributing that many carbons, so PA12 comes from a twelve carbon unit. Two numbers mean a diamine and a diacid, so PA66 comes from two monomers of six carbons each.
Is polyamide a plastic?
Yes. Polyamide is a thermoplastic polymer, so nylon material in any of its grades is a plastic. The textile use of the word describes fibres drawn from the same polymer family.
Which polyamide grade is best for 3D printed production parts?
PA12 for most industrial laser sintering work, because it prints predictably and holds dimension in humid environments. PA11 is the choice when impact resistance outweighs cost, and filled grades when stiffness or heat resistance matters more than ductility.
Not Sure Which Polyamide Your Part Needs?
Send us the part and the environment it lives in, the temperature, the humidity, the loads and the cycle count, and our team will tell you which grade and process actually fit, including when the answer is not a printed part at all.
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