PETG vs Nylon for 3D Printed Parts: Which Should You Specify?
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PETG and nylon both get called tough plastics, and on a spec sheet their tensile numbers can look close. In production they behave very differently. PETG is the easy, stable, low-cost material you reach for by default; nylon is the engineering workhorse you reach for when a part has to survive wear, repeated flex, heat, or aggressive chemicals.
This comparison is for engineers choosing a material for functional parts — brackets, housings, gears, bushings, guides, and wear components.
The Short Answer
PETG for cost-effective, dimensionally stable, easy-to-produce general-purpose parts — especially in humidity or food contact. Nylon when the part has to take wear, repeated flex, heat, or fuels and solvents. If the part just needs to hold a shape and take light duty, PETG; if it has a hard life, nylon.
Side-by-Side
| Property | PETG | Nylon (PA6 / PA12) |
|---|---|---|
| Toughness & fatigue | Good, but can crack under repeated flex | Excellent — repeated flex, living hinges, impact |
| Wear / abrasion | Moderate | Excellent — self-lubricating; gears, bushings, wear parts |
| Heat resistance | ~70°C | Much higher — grades for continuous use well past 100°C, filled grades to ~150°C+ |
| Chemical resistance | Good (water, dilute acids) | Excellent — fuels, oils, many solvents |
| Moisture behavior | Low absorption — dimensionally stable in humidity | Hygroscopic — absorbs moisture, swells and softens unless dried and managed |
| Dimensional stability | Excellent, predictable | Good once conditioned, but moisture-sensitive |
| Tensile strength | ~45–50 MPa | ~45–70 MPa (higher, especially filled grades) |
| Food-contact grades | Available | Limited |
| Printing in production | Easy, forgiving | Demanding — must be dried, enclosed; warps |
| Relative cost | Lower | Higher |
Typical values for production FDM grades — datasheets available on request.
Where PETG Wins
- Cost-sensitive general-purpose parts — enclosures, brackets, panels, and housings that take light to moderate duty.
- Humid or wet environments — this is the big one. PETG barely absorbs moisture, so parts hold their dimensions where nylon would swell. If a part has to stay dimensionally stable in damp service, PETG often wins outright.
- Food-contact parts — food-safe grades are available (final food-contact safety also depends on the part's process and use).
- Clear or translucent parts — PETG runs translucent grades.
- Fast, reliable production — PETG is forgiving to print, so runs are predictable and quick.
Where Nylon Wins
- Moving and wearing parts — gears, bushings, cams, latches, and living hinges. Nylon is self-lubricating and shrugs off abrasion and repeated flex that would fatigue PETG.
- Heat — parts near motors, engines, and warm equipment, well above PETG's ~70°C ceiling.
- Fuels, oils, and solvents — nylon's chemical resistance is in a different class.
- Impact and fatigue under repeated load — parts that get hit, flexed, or cycled.
When a nylon part also needs metal-like stiffness, the filled grades are the answer: glass filled nylon for dimensional stability and stiffness, or carbon fiber nylon for maximum stiffness-to-weight and metal replacement.
The Nylon Moisture Caveat
Nylon pulls water out of the air. As it does, it changes dimensions and softens — which is why unmanaged nylon parts drift out of spec in humid service. We dry nylon before and during printing and account for it in production, but it is a real engineering constraint: for a dimensionally critical part that will live somewhere damp, PETG or a stabilized filled nylon is often the better call than unfilled nylon. It is exactly the kind of trade-off we will flag when you send a part.
When Neither Is Right
- Permanent outdoor / UV exposure — step to ASA, the material engineered for sun.
- Flexible or sealing parts — that's TPU.
- Sustained high heat plus high impact in a rigid part — polycarbonate.
How Chatelet Runs These Materials
We print PETG and nylon in production quantities on our 85+ printer fleet in Orlando, Florida. PETG is forgiving and runs fast; nylon is dried and printed in an enclosed, temperature-controlled process so parts come out strong and dimensionally correct instead of warped and weak. That process control is the difference between a nylon datasheet number and a nylon part that actually performs. Turnaround can be as soon as one week depending on part complexity and volume.
Full material details: PETG | Nylon. Related reading: Carbon Fiber Nylon vs Aluminum.
FAQ
Is nylon stronger than PETG?
Nylon is tougher and far more resistant to wear, fatigue, heat, and chemicals; tensile strength ranges from comparable to higher, especially in filled grades. The meaningful difference is durability under stress, not the headline tensile number.
Which is better in wet or humid conditions, PETG or nylon?
PETG. It absorbs very little moisture and holds its dimensions, while nylon is hygroscopic and will swell and soften in humidity unless it is dried and managed. For dimensionally critical parts in damp service, PETG is often the safer choice.
Does nylon really absorb water?
Yes — nylon pulls moisture from the air, which changes its dimensions and softens it. We dry it before and during printing to control this, but it remains a genuine design consideration for humid environments.
Which should I use for gears or moving parts?
Nylon. It is self-lubricating and resists abrasion and repeated flex, which makes it the standard choice for gears, bushings, and wear surfaces where PETG would wear or fatigue.
Which is cheaper and easier to produce?
PETG. It costs less and is much more forgiving to print, so production runs are faster and more predictable. Nylon costs more and demands a controlled, dried printing process.
Get Your Part Quoted
Not sure which material fits your part? Send us your CAD file with the load case and environment — wear, heat, chemicals, humidity — and we'll recommend the right material and production path, even if it isn't the one you asked about.
Chatelet Manufacturing is a US-based contract manufacturer in Orlando, Florida, operating 85+ FDM production printers. We produce PETG, nylon, carbon fiber nylon, glass filled nylon, ASA, polycarbonate, and TPU parts from prototype through low-volume production, with turnaround as soon as one week depending on part complexity and volume.