Nylon vs Polycarbonate Strength: Which Engineering Filament is Stronger?

The Core Tradeoff: Toughness vs Stiffness

Nylon (PA) and polycarbonate (PC) are both engineering-grade filaments that outperform PLA, PETG, and ABS in demanding applications. But they occupy different mechanical niches. Nylon is a tough, somewhat flexible material that absorbs energy before breaking. Polycarbonate is stiffer, more dimensionally stable, and handles higher temperatures — but it sacrifices ductility for that rigidity.

The right choice depends on what kind of "strong" you need. A hinge that flexes thousands of times needs toughness. A structural bracket holding a fixed load needs stiffness and high HDT. Understanding which mechanical property governs your use case is the key to choosing correctly.

Tensile Strength: Raw Pull Force

Tensile strength (MPa) tells you how much axial force a material withstands before fracturing. For parts under sustained tension — hooks, brackets, structural ties — this is the headline number.

Across the Filabase database, standard unfilled nylon grades cluster between 43 and 80 MPa:

• 3DXTech AmideX Nylon 6-66: 55 MPa tensile, 100% elongation
• 3DXTech WearX Nylon: 62 MPa tensile, 18% elongation
• Polymaker PolyMide CoPA: 66.2 MPa tensile, 9.9% elongation
• Sunlu Easy PA: 75 MPa tensile, 32% elongation
• Overture Easy Nylon: 71.3 MPa tensile, 8.4% elongation

Standard PC grades span a similar range — 40 to 74.6 MPa — but with much lower elongation at break:

• Bambu Lab PC: 55 MPa tensile, 3.8% elongation
• 3DXTech 3DXMAX PC: 62 MPa tensile, 7% elongation
• Overture PC Professional: 70.2 MPa tensile, 6.7% elongation
• Polymaker PolyLite PC: 69.1 MPa tensile, 4.8% elongation
• Polymaker PolyCore PC-7413: 74.6 MPa tensile, 2.39% elongation

At the top end, PC pulls slightly ahead on tensile numbers. But this comparison is incomplete without elongation. The 3DXTech AmideX Nylon 6-66 at 55 MPa and 100% elongation will absorb far more energy before fracture than any standard PC at 62 MPa and 5% elongation.

Practical takeaway: On raw tensile numbers, PC and nylon are competitive — roughly 50–75 MPa for both material families. But tensile strength alone doesn't capture how a material behaves at failure. Nylon stretches and deforms; PC snaps.

Flexural Strength and Modulus: Stiffness Under Bending

Flexural strength (MPa) measures resistance to bending before breaking. Flexural modulus (MPa) measures stiffness — how much a material resists bending deformation before any failure occurs. High modulus = stiffer part.

This is where PC clearly separates itself from standard nylon. PC has a meaningfully higher flexural modulus:

• Anycubic PC: 105 MPa flexural strength, 2,900 MPa flexural modulus
• Bambu Lab PC: 108 MPa flexural strength, 2,310 MPa flexural modulus
• Elegoo PC: 109 MPa flexural strength, 2,615 MPa flexural modulus
• 3DXTech 3DXMAX PC: 78 MPa flexural strength, 2,200 MPa flexural modulus

Standard unfilled nylon grades typically deliver lower flexural modulus:

• 3DXTech AmideX Nylon 6-66: 76 MPa flexural strength, 2,050 MPa flexural modulus
• Sunlu Easy PA: 98 MPa flexural strength, 2,350 MPa flexural modulus
• MatterHackers PRO Series Nylon: 91.7 MPa flexural strength, 2,523 MPa flexural modulus
• Fillamentum Porthcurno: 70 MPa flexural strength, 2,100 MPa flexural modulus

Some premium nylon grades close the gap substantially. The 3DXTech WearX Nylon (2,215 MPa flexural modulus) and Spectrum PA6 Low Warp (2,800 MPa flexural modulus) compete with standard PC on stiffness. But for most commodity grades, PC delivers 10–30% higher flexural modulus than equivalent nylon.

Practical takeaway: PC is the stiffer material. For dimensionally stable, rigid parts that must not flex under load — machine components, structural housings, optical mounts — PC's higher flexural modulus is a real advantage.

Impact Resistance: Which Survives Drops and Shock?

Polycarbonate is famously tough in injection-molded form — it's used for bullet-resistant glass and safety helmets. In FDM printing, however, layer adhesion limits impact resistance significantly, and this reputation often leads users to expect better impact performance than they actually get.

The elongation data tells a clear story about which material will absorb more energy before catastrophic fracture. Nylon's high elongation values — 3DXTech AmideX Nylon 6-66 at 100%, eSUN PA at 164.88%, MatterHackers MH Build Series Nylon at 175.32% — means the material deforms substantially before breaking, absorbing significant energy in the process.

PC elongation across the database ranges mostly from 2.4% to 14%:

• Bambu Lab PC FR: 2.4% elongation
• Polymaker PolyCore PC-7413: 2.39% elongation
• Bambu Lab PC: 3.8% elongation
• 3DXTech ezPC: 14% elongation (near the top of standard PC grades)
• Sunlu PC: 25% elongation (notably flexible for a PC grade)

In FDM printing specifically, layer bonds are the weakest link for both materials. Nylon's natural flexibility and moisture resistance help maintain some ductility across layer interfaces. PC's high processing temperature requirements (260–295°C nozzle, 100–140°C bed) help layer adhesion but don't recover the intrinsic toughness of injection-molded PC.

Practical takeaway: For parts that must survive drops, vibration, or repeated shock, nylon's toughness profile (high elongation, energy absorption) makes it the better choice. PC's impact reputation is largely from injection molding — in FDM, nylon edges it out for shock resistance.

Heat Deflection Temperature: Thermal Strength

Both materials significantly outperform PLA and PETG on heat resistance, but the ranges are quite different.

Standard nylon grades vary widely depending on the PA type:

• PA12 grades typically deflect at 50–55°C (softer) — Fiberlogy Nylon PA12: HDT 55°C
• PA6 grades run much hotter — 3DXTech AmideX Nylon 6-66: HDT 140°C
• PA612 and PA6 glass-filled grades reach 157–215°C — Fiberon PA612-ESD: HDT 157°C

PC grades cluster more consistently in the 99–141°C range:

• IEMAI PC: HDT 99.3°C
• Bambu Lab PC: HDT 117°C
• 3DXTech 3DXMAX PC: HDT 135°C
• Polymaker PolyCore PC-7413: HDT 139°C
• Prusament PC Space Grade: HDT 137°C

The key distinction: PA6-based nylons overlap directly with PC on HDT, while PA12-based nylons fall significantly below. When someone says "nylon has poor heat resistance," they're usually thinking of PA12. PA6 grades (which print at 250–280°C) are thermally competitive with mid-range PC.

Practical takeaway: If thermal stability is the primary concern, choose PA6 or a high-temperature PA grade rather than PA12, or use PC. PA12 is not a heat-resistant material despite being a "nylon."

Printability: Which Is Easier to Work With?

Both materials are significantly harder to print than PLA or PETG, but they fail in different ways.

Nylon Printability

Nylon's primary challenge is moisture absorption. PA is hygroscopic — it absorbs moisture from the air rapidly, causing stringing, bubbling, and poor layer adhesion. Filament must be dried before printing (typically 70–80°C for 4–8 hours) and ideally printed from a dry box. Print temperatures for standard PA grades range from 240–290°C. Bed temperatures: 60–100°C with PEI or garolite surfaces recommended. Warping is moderate compared to ABS but still requires bed preparation.

Print temperature ranges from the database:

• 3DXTech AmideX Nylon 6-66: 270°C nozzle, 80°C bed
• Polymaker PolyMide CoPA: 250°C nozzle, 60–80°C bed
• Sunlu Easy PA: 250–280°C nozzle, 60–80°C bed
• Overture Easy Nylon: 245–260°C nozzle

Polycarbonate Printability

PC requires higher temperatures than most desktop printers can deliver at stock settings. Nozzle temperatures of 260–295°C are standard, and bed temperatures of 90–140°C are required to prevent warping. PC also warps severely — an enclosure is essentially mandatory. Many entry-level printers cannot reliably print PC without hotend upgrades.

Print temperature ranges from the database:

• Bambu Lab PC: 260–280°C nozzle, 90–110°C bed
• 3DXTech 3DXMAX PC: 275–295°C nozzle, 110–120°C bed
• Prusament PC Space Grade: 290°C nozzle, 110°C bed
• FormFutura Kratos PC CF10: 270–310°C nozzle, 100–130°C bed

PC blends (PC/ABS, PC/ASA) reduce printing difficulty significantly while preserving most of the thermal performance. The 3DXTech 3DXMAX PC/ABS prints at 275°C with HDT of 126°C — more accessible than pure PC while maintaining most of the engineering advantage.

Practical takeaway: Nylon is easier to print if you manage moisture properly. PC requires higher temperatures and an enclosure but doesn't have the moisture-sensitivity issue. "Easy" PC blends offer a middle ground.

Reinforced Grades: CF and GF Push Both Materials Higher

Both PA and PC are commonly available in carbon fiber (CF) and glass fiber (GF) reinforced variants that dramatically increase stiffness and sometimes tensile strength. These are worth considering if raw polymer properties aren't enough.

Top PA-CF grades from the database:

• Bambu Lab PA6-CF: 102 MPa tensile, 151 MPa flexural, 5,460 MPa flexural modulus, HDT 164°C
• Fiberon PA6-CF20: 109.3 MPa tensile, 161 MPa flexural, 7,037.6 MPa flexural modulus, HDT 215°C
• 3DXTech CarbonX HTN+CF: 87 MPa tensile, 95 MPa flexural, 7,895 MPa flexural modulus, HDT 240°C

Top PC-CF grades from the database:

• 3DXTech CarbonX PC+CF: 70 MPa tensile, 90 MPa flexural, 5,890 MPa flexural modulus, HDT 135°C
• 3DXTech CarbonX ezPC+CF: 73 MPa tensile, 85 MPa flexural, 6,540 MPa flexural modulus, HDT 119°C

The reinforced PA grades substantially outperform reinforced PC grades on flexural modulus and thermal performance when comparing CF variants. PA6-CF at 7,000+ MPa flexural modulus and 215°C HDT versus PC-CF at 5,890 MPa and 135°C is a decisive difference for high-performance parts.

Practical takeaway: If you're considering CF filaments, PA-CF typically outperforms PC-CF on both stiffness and thermal resistance. PA-CF is the stronger choice in the reinforced category.

Head-to-Head Summary Table

Which Should You Choose?

Choose Nylon (PA) When:

• The part experiences repeated flexing, snap fits, or living hinges
• Impact resistance and shock absorption matter (enclosures, protective covers, tooling)
• You need wear resistance (gears, sliding parts, bushings)
• You want high-temperature PA6 performance without PC's printing difficulty
• You're using CF reinforcement — PA-CF outperforms PC-CF on stiffness and HDT

Choose Polycarbonate (PC) When:

• The part needs to be rigid and dimensionally stable under load
• You need reliable 110–140°C heat deflection with consistent geometry
• Optical clarity matters (PC can be printed semi-transparent)
• You need flame-retardant properties — several PC grades offer UL94 ratings
• You can't manage moisture-sensitive filament storage requirements

Consider PC Blends (PC/ABS, PC/ASA) When:

• Pure PC's print requirements are too demanding for your setup
• 3DXTech 3DXMAX PC/ABS (59 MPa tensile, 126°C HDT) prints at 275°C and provides most of PC's engineering value at lower difficulty
• BASF Ultrafuse PC/ABS FR adds flame retardancy at 260–280°C print temperature

The Bottom Line

There's no single winner between nylon and polycarbonate — it depends entirely on the type of strength your application requires. Polycarbonate is stiffer and more dimensionally stable, with consistent heat resistance in the 100–140°C range. Nylon is tougher, more ductile, and in PA6/PA-CF form can match or exceed PC on both thermal performance and reinforced stiffness.

For most functional printing applications — gears, brackets, snap fits, mechanical components — nylon's combination of toughness and printability makes it the more practical choice. Polycarbonate earns its place in rigid structural housings, high-temperature enclosures, and applications where stiffness matters more than energy absorption.

If you've used both materials and find the numbers don't match your experience, the most likely explanation is moisture: wet nylon performs dramatically worse than dried nylon, and it's easy to attribute the difference to the material rather than the process.