Nylon Filaments Guide: PA6, PA12, PA11, CF Variants & More

Nylon filaments guide showcases different types like PA6, PA12, PA11, and carbon fiber variants for 3D printing.

Nylon filament is not one single material. In FDM printing, nylon usually means a family of polyamides: PA6, PA12, PA11, PA-CF, PA-GF, PAHT-CF and several modified blends. They share the same broad character — toughness, wear resistance, fatigue resistance and chemical resistance — but their printing behavior can be very different. PA6 absorbs more moisture, PA12 tends to be more dimensionally stable, PA11 often brings a balanced mix of toughness and heat behavior, while carbon fiber variants trade some ductility for stiffness and lower warp.

Nylon filament types compared by typical printing behavior, moisture response, stiffness and common technical use.
Nylon Type	Polyamide Base	Typical Nozzle Range	Typical Bed Range	Moisture Behavior	Main Strength Area	Common Use
PA6	Polyamide 6	250–290°C	70–100°C	Higher moisture uptake than PA12	High toughness, strong layer bonding	Gears, hinges, clips, wear parts
PA12	Polyamide 12	240–280°C	70–100°C	Lower moisture sensitivity than PA6	Dimensional stability, chemical resistance	Jigs, fixtures, housings, snap-fit parts
PA11	Polyamide 11	270–295°C	90–115°C	Moderate moisture uptake, varies by blend	Toughness, impact behavior, heat resistance	Functional prototypes, brackets, durable end-use parts
PA6-CF	PA6 with carbon fiber	280–300°C	25–50°C on some engineered grades	Still moisture-sensitive	High stiffness and heat deflection	Rigid tooling, brackets, fixtures, loaded parts
PA12-CF	PA12 with carbon fiber	260–300°C	25–60°C on some engineered grades	Lower moisture uptake than PA6-CF	Stable rigid parts with cleaner geometry	Manufacturing tools, mounts, low-warp parts
PA11-CF	PA11 with carbon fiber	Around 285°C	Around 110°C	Low short-term moisture uptake in some datasheets	Heat resistance and balanced strength	Heat-exposed brackets, stiff mechanical parts
PAHT-CF	High-temperature polyamide with carbon fiber	270–300°C	90–110°C	Usually formulated for lower moisture effect	Heat resistance, stiffness, controlled shrinkage	Engineering fixtures, ESD-safe variants, warm-service parts

Datasheet values for nylon filaments are best read as trend data, not universal promises. A PA6-CF spool from one maker may show a different modulus, heat deflection temperature or drying response than another PA6-CF spool because fiber loading, base resin, annealing, print orientation and moisture state all change the final part.

What Nylon Means in FDM Printing

Nylon is the common printing name for polyamide. The “PA” code tells you the polymer family, while the number hints at the molecular structure. PA6, PA11 and PA12 are not just marketing labels. They behave differently during extrusion, cooling, storage and real use.

The main reason nylon feels different from PLA, PETG or ABS is its chain structure. Polyamides form strong intermolecular attraction, which helps with toughness, abrasion behavior and fatigue resistance. That same chemistry also attracts water. Dry nylon prints smoother, bonds better and keeps dimensions more predictably. Wet nylon can hiss, foam, string and lose surface quality.

Not all nylon is equally thirsty. PA6 absorbs moisture faster than PA12 in typical printing use, while PA12 is often selected when lower moisture sensitivity and cleaner dimensional control matter more than maximum toughness.

PA6 Nylon Filament

PA6, also called Nylon 6, is one of the classic engineering nylons. In 3D printing, it is valued for toughness, wear behavior and strong interlayer bonding. It can make parts that survive bending and repeated stress better than many rigid commodity filaments.

The tradeoff is moisture management. PA6 absorbs water readily, and print quality changes fast when the spool is not dry. The material may still extrude, but bubbles, rough walls and weaker part consistency often appear. For PA6, drying is not a small detail. It is part of the material.

PA6 Printing Character

Layer bonding: often very good when the filament is dry and the chamber is warm.
Impact behavior: well suited to flexible-tough mechanical parts.
Warp tendency: higher than PA12, especially on wide flat parts.
Moisture effect: strong; surface finish and strength can shift quickly.
Bed adhesion: usually needs the correct surface and release layer to avoid either lifting or over-bonding.

PA6 fits moving parts, clips, living-hinge style geometry, sliding elements and mechanical items where toughness matters more than sharp cosmetic detail.

PA12 Nylon Filament

PA12, or Nylon 12, is usually the calmer nylon in desktop and professional FDM printing. It absorbs moisture more slowly than PA6 and often prints with less warp. That makes it attractive for fixtures, housings, clean mechanical prototypes and parts where dimensions must stay close to the CAD model.

PA12 does not replace PA6 in every role. It usually has a different balance: more stable, less moisture-sensitive, often less tough in extreme flex than PA6. For many printed parts, that balance is useful. Clean fit matters.

PA12 Printing Character

Dimensional stability: usually better than PA6 on large or flat parts.
Moisture behavior: lower uptake, but still benefits from dry storage.
Chemical resistance: often a strong reason to choose PA12 for technical parts.
Surface finish: tends to be cleaner than wetter or more warp-prone nylon grades.
Use case: excellent for jigs, fixtures, covers, brackets and functional housings.

Polymaker’s PA12-CF technical data sheet lists an estimated equilibrium water absorption around 1.5% for its reinforced PA12-CF material, showing the lower moisture direction often associated with PA12-based nylon blends.[a]

PA11 Nylon Filament

PA11, or Nylon 11, sits between the more common PA6 and PA12 choices in many printer material lineups. It is used when toughness, impact behavior, heat resistance and a lighter moisture profile are wanted in the same material family.

One reason PA11 gets attention is its feedstock story. Industrial PA11 resins are known for castor-oil origin in some product families, including Arkema’s Rilsan PA11 resin line.[b] In filament selection, that origin is secondary to the datasheet. The part still needs the right nozzle, dry material and correct print surface.

Prusament PA11 Carbon Fiber lists polyamide 11 filled with carbon fibers, a 285 ± 5°C nozzle temperature and a 110 ± 10°C heated bed in its technical data sheet.[c] Those numbers place PA11-CF firmly in technical printer territory.

Carbon Fiber Nylon: PA-CF, PA6-CF, PA12-CF and PA11-CF

Carbon fiber filled nylon uses chopped carbon fibers inside the polyamide base. The fibers raise stiffness, reduce shrinkage and give parts a matte technical surface. They also make the filament abrasive. A hardened nozzle is not optional for long use.

The change is easy to feel in the hand: unfilled nylon can bend and spring back, while PA-CF feels more rigid and controlled. That is useful for brackets, tooling, motor mounts and structural fixtures. The printed part is still anisotropic, so layer direction remains important.

PA6-CF

PA6-CF is the stiffer, hotter-running version of PA6 in many filament catalogs. Polymaker’s PA6-CF data sheet lists 1.17 g/cm³ density, 218.5°C melting temperature and heat deflection temperature values of 173°C at 1.8 MPa and 215°C at 0.45 MPa after the stated conditioning and annealing process.[d]

That makes PA6-CF attractive for parts that need stiffness and heat resistance. It still needs dry handling. Carbon fiber does not remove PA6’s moisture sensitivity.

PA12-CF

PA12-CF is usually selected when the printer user wants carbon-fiber stiffness with lower moisture effect and cleaner dimensions. In Polymaker’s PA12-CF sheet, the material is described as carbon fiber reinforced PA12, with a 1.06 g/cm³ density and a 165°C melting temperature.[e]

Its heat deflection temperature is lower than the PA6-CF example above, but the material can be easier to control in prints where geometry accuracy matters. Less drama, cleaner parts.

PA11-CF

PA11-CF has a useful middle character. In Prusament’s published values, PA11-CF lists heat deflection temperature of 192°C at 0.45 MPa and 152°C at 1.80 MPa, with 24-hour moisture absorption reported as 0.20% under the stated test condition.[f]

For users comparing PA11-CF against PA12-CF, the difference is not only strength. The more useful question is whether the part needs heat resistance, lower warp, higher impact behavior, a specific print surface or a cleaner tolerance range.

PAHT-CF

PAHT-CF means high-temperature polyamide with carbon fiber. It is not always PA6, PA11 or PA12 in a simple form; many PAHT filaments are engineered blends. BASF Forward AM’s Ultrafuse PAHT CF15 is presented as a reinforced filament with chemical resistance and ESD-safe behavior in its extended technical documentation.[g]

PAHT-CF is usually chosen for warm-service tooling, fixtures and loaded parts where a standard nylon blend may not hold shape as well. Printer capability matters here: hotend temperature, bed temperature, chamber stability and nozzle material all need to match the filament.

Glass Fiber, Aramid and Other Nylon Variants

Carbon fiber gets most attention, but it is not the only reinforcement used with nylon filament. Glass fiber nylon and aramid-filled nylon serve different mechanical needs.

PA-GF: glass fiber filled nylon. Often stiff, dimensionally stable and less electrically conductive than carbon fiber grades.
PA-CF: carbon fiber filled nylon. Stiff, matte, low-shrink and abrasive to brass nozzles.
PA-Aramid: aramid fiber filled nylon. Often selected for impact behavior, wear behavior and fiber-toughened parts.
Lubricated PA: nylon blends with additives for sliding surfaces, bushings or wear-focused parts.
ESD PA: nylon formulated for controlled surface resistance in electronics handling, fixtures or trays.

The reinforcement changes the part, not just the print settings. Fibers can reduce shrinkage, raise modulus and improve the feel of precision, but they also reduce some of the flexible nature that makes unfilled nylon useful.

Moisture: The Detail That Changes Nylon Prints

Nylon is hygroscopic. That means it takes in moisture from the air. The effect is visible during extrusion: wet nylon may pop at the nozzle, leave a rough surface, form strings and weaken the clean flow needed for consistent layer bonding.

This is why two users can print the same nylon and report different results. One spool may be fresh and dry; another may have sat open for a few days in a humid room. Same material name. Different print.

Moisture Behavior by Nylon Type

Relative moisture behavior of common nylon filament families used in FDM printing.
Material	Moisture Sensitivity	Typical Print Effect When Wet	Storage Priority
PA6	High	Popping, stringing, rough walls, variable strength	Very high
PA12	Moderate to lower	Stringing and surface dullness after longer exposure	High
PA11	Moderate, blend-dependent	Surface texture change and flow inconsistency	High
PA6-CF	High	Rough surface, weaker consistency, brittle feel in thin details	Very high
PA12-CF	Moderate to lower	Cleaner than PA6-CF, but still affected by moisture	High
PAHT-CF	Blend-dependent	Flow and surface quality changes	High

Drying temperatures depend on the filament maker. Many nylon products use drying ranges around 70–90°C, but the safe value should come from the spool’s own documentation. Some spools, RFID cores or plastic reels do not tolerate high drying temperatures. The filament may be heat-ready while the spool is not.

Printing Requirements for Nylon Filaments

Nylon rewards a controlled printer setup. It does not always need an industrial machine, but it needs more attention than PLA. The main areas are hotend temperature, bed surface, chamber control, nozzle type and dry feeding.

Hotend and Nozzle

Unfilled PA12 may print at lower temperatures than PA6-CF or PA11-CF. Carbon fiber nylon often needs a hotend capable of 280–300°C. PTFE-lined hotends are not the right match for many nylon grades at these temperatures; all-metal hotends are the normal choice.

For CF and GF variants, use a hardened steel, tungsten carbide, ruby or similar wear-resistant nozzle. Polymaker’s PA6-CF and PA12-CF documentation notes frequent abrasion of brass nozzles and recommends wear-resistant nozzles for these materials.[h]

Build Surface

Nylon bed adhesion can move in two directions: not enough grip, or too much grip. Some surfaces need glue as an adhesive; others need glue as a release layer. This is why the correct sheet matters. PA can bond too strongly to certain surfaces and damage them during removal.

Chamber Temperature

A warm, stable chamber helps reduce warp on PA6, PA11 and many unfilled nylon grades. PA12 and PA-CF blends often behave better, but large parts still benefit from slower cooling. Drafts are not friendly to nylon.

Cooling Fan

Many nylon profiles use little or no part cooling. Too much cooling can reduce layer bonding and increase curl. Small overhangs may need limited airflow, but the material usually prefers heat retention over aggressive cooling.

Mechanical Behavior: Toughness, Stiffness and Layer Direction

Nylon is often chosen for functional parts because it handles real motion well. It can flex, absorb impact and resist wear. Carbon fiber nylon changes that behavior: it raises stiffness, improves dimensional control and reduces the rubbery feel, but the part becomes less flexible.

Printed nylon parts are direction-sensitive. A tensile bar printed flat will not behave the same as one loaded across layer lines. This matters more with nylon than many people expect because nylon can be very strong in one direction and less reliable in another if the print is wet, underheated or poorly oriented.

Typical mechanical direction of nylon filament choices for functional printed parts.
Part Requirement	Better Nylon Direction	Reason
Flexible clip or snap feature	Unfilled PA6, PA11 or PA12	More ductile behavior than fiber-filled grades
Rigid bracket	PA6-CF, PA12-CF, PA11-CF or PAHT-CF	Higher modulus and lower shrinkage
Wear surface	Unfilled PA or lubricated PA blend	Good abrasion and sliding behavior
Heat-exposed fixture	PA6-CF, PA11-CF or PAHT-CF	Better heat deflection in suitable grades
Dimension-sensitive tooling	PA12-CF or PAHT-CF	Lower warp and more controlled shrinkage

ISO 527 is often used for tensile testing of plastics and plastic composites under defined conditions, which is why many filament data sheets list tensile strength and tensile modulus using ISO 527 methods.[i] The values are useful for comparison, but print settings and part geometry still decide the real part.

PA6 vs PA12 vs PA11

The easiest way to understand nylon families is to separate toughness, moisture behavior and dimensional control.

PA6, PA12 and PA11 compared as base nylon families before reinforcement.
Property Direction	PA6	PA12	PA11
Toughness	Very strong area	Good, often more controlled	Good balance of toughness and heat behavior
Moisture Sensitivity	Higher	Lower than PA6	Moderate, formulation-dependent
Warp Control	Needs more care	Usually easier	Moderate, depends on blend and filler
Heat Resistance	Strong in reinforced grades	Moderate to strong in reinforced grades	Strong in some CF grades
Best Fit	Tough, wear-resistant parts	Stable engineering parts	Balanced functional and heat-aware parts

PA6 is the more demanding choice, but it brings excellent toughness. PA12 is often the cleaner and more predictable choice. PA11 is a strong technical option when the filament maker has tuned the blend for heat, impact behavior and print control.

Unfilled Nylon vs Carbon Fiber Nylon

Unfilled nylon and carbon fiber nylon should not be treated as small variations of the same spool. They serve different part designs.

Use unfilled nylon when the part needs bend, snap, impact absorption or wear resistance.
Use PA-CF when the part needs stiffness, flatness, low shrinkage and a more precise mechanical feel.
Use PA12-CF when lower moisture sensitivity and cleaner print geometry matter.
Use PA6-CF when stiffness and heat resistance are more important than easy handling.
Use PA11-CF when heat behavior, impact resistance and controlled stiffness are all part of the target.

Carbon fiber also changes machining and finishing. The matte surface hides layer lines well, but it can be harder on tools. Thin carbon-filled sections may feel rigid, yet they are not always the best choice for springy clips. The fiber does its job. It stiffens.

Annealing Nylon Parts

Some nylon and PA-CF data sheets include annealing steps. Annealing can improve heat resistance and crystallinity, but it can also change dimensions. Polymaker’s PA6-CF sheet recommends annealing printed models at 80–100°C for 6 hours after printing, while its PA12-CF sheet lists 80°C for 6 hours.[j]

Annealing is most useful when the printed part must work near elevated temperatures. It is less attractive for parts where tight dimensions matter and no test print has been measured after heat treatment.

Support Materials and Multi-Material Printing

Nylon can be difficult with supports because layer bonding is strong and moisture changes separation behavior. Some nylon prints use breakaway supports made from the same material; others use dedicated support materials, depending on the printer and filament system.

For PA-CF, support removal should be planned early. Reinforced nylon is less forgiving when a support scar lands on a functional bearing surface or sealing face. Clean design beats heavy support cleanup.

Common Nylon Filament Selection Mistakes

The most common nylon mistake is choosing only by the word “nylon” on the label. PA6, PA12 and PA11 do not print the same. The second mistake is printing from an open spool and blaming the material for wet-spool behavior.

Ignoring the base polymer: PA6 and PA12 have different moisture and warp patterns.
Using brass nozzles with filled nylon: CF and GF grades wear brass quickly.
Skipping dry storage: nylon can change print behavior after air exposure.
Overcooling the print: too much fan can reduce layer bonding.
Reading datasheets without test conditions: annealed, dry, conditioned and printed values may not match a fresh part from a different printer.

Best Nylon Filament by Part Type

Nylon filament choice by functional part requirement.
Part Type	Suitable Nylon Family	Why It Fits
Living hinge or flexible clip	Unfilled PA6, PA11 or PA12	Better ductility than fiber-filled nylon
Gear or sliding part	PA6, PA12 or lubricated PA	Wear resistance and lower friction behavior
Flat bracket	PA12-CF or PAHT-CF	Lower shrinkage and higher stiffness
Heat-exposed mount	PA6-CF, PA11-CF or PAHT-CF	Higher heat deflection in suitable grades
Chemical-contact fixture	PA12 or PA12-CF	Good chemical resistance in many environments
Impact-ready prototype	PA11 or PA6	Toughness and energy absorption

For real parts, the best nylon is the one that matches the load path. A rigid CF bracket and a flexible snap clip are both “nylon parts,” but they need different material behavior.

Datasheet Numbers Worth Reading

Nylon datasheets can look dense, but only a few values decide most filament choices.

Tensile modulus: higher values mean a stiffer part.
Tensile strength: useful for load comparison, but print direction matters.
Elongation at break: helps judge ductility and flex behavior.
Charpy impact: useful for impact-prone parts.
HDT: heat deflection temperature; important for warm fixtures and brackets.
Water absorption: affects storage, print quality and part conditioning.
Recommended annealing: changes final heat behavior and dimensions.

Fiberlogy’s Nylon PA12+CF15 sheet lists 15% carbon fiber in the material name and reports 120 MPa tensile strength at break, 7300 MPa tensile modulus and HDT values of 170°C at 0.45 MPa and 150°C at 1.8 MPa under its stated test methods.[k] Those numbers show why PA12-CF15 is used for rigid technical parts rather than soft flex features.

Practical Material Matching

For a desktop printer with a standard hotend, PA12 or a lower-temperature nylon blend is usually the most realistic entry point. For a printer with an all-metal hotend, enclosure and dry box, PA6, PA11 and CF variants become more practical.

For the cleanest first nylon experience, PA12 or PA12-CF is often easier to control than PA6. For maximum toughness, PA6 remains very attractive. For a balanced technical print with heat resistance and stiffness, PA11-CF and PAHT-CF are worth comparing by datasheet, not just by name.