This nylon 6 nylon guide explains practical considerations for material selection, design review, manufacturing, and sourcing decisions.
Nylon 6 vs Nylon 66 is one of the most common engineering plastic comparisons because the best choice depends on moisture exposure, strength targets, heat load, and processing needs.
In short, Nylon 6 is often preferred for toughness, easier processing, and lower cost, while Nylon 66 is usually chosen when higher heat resistance, stiffness, and creep performance matter more. For reinforced grades, see our PA66 GF30 guide and for fluid exposure, compare nylon chemical resistance.
Chemical Structure Differences
The fundamental difference between PA6 (Nylon 6) et PA66 (nylon 66) lies in their molecular structure:
- Nylon 6: Made from caprolactam, has 6 carbon atoms in each repeating unit. Less crystalline structure.
- Nylon 66: Made from hexamethylenediamine and adipic acid, has two 6-carbon chains. More crystalline structure.
Comparaison des propriétés mécaniques
| Propriété | PA6 | PA66 |
|---|---|---|
| Résistance à la traction | 70-85 MPa | 80-100 MPa |
| Module de flexion | 2.5-3.0 GPa | 2.8-3.5 GPa |
| Allongement à la rupture | 30-100% | 15-60% |
| Résistance au choc Izod avec entaille | 50-100 J/m | 40-80 J/m |
| Point de fusion | 220°C | 260 °C |
| HDT à 1,8 MPa | 70°C | 90°C |
Absorption de l'humidité
Moisture absorption is critical for nylon applications:
| Condition | PA6 | PA66 |
|---|---|---|
| At 50% RH | 2.5-3.0% | 2.0-2.5% |
| Saturation | 8-10% | 6-8% |
Processing Characteristics
Nylon 6 Processing
- Point de fusion : 220°C
- Processing Range: 240-280°C
- Température du moule : 40 à 80 °C
Nylon 66 Processing
- Point de fusion : 260 °C
- Processing Range: 280-320°C
- Température du moule : 60-90°C
Applications by Material
Nylon 6 Applications
- Gears and sprockets
- Industrial monofilament
- Film and packaging
- Consumer products
Nylon 66 Applications
- Automotive under-hood components
- Electrical connectors
- High-temperature bearings
- Precision mechanical components
Reinforced Grades
Both materials are commonly reinforced with glass fiber:
| Grade | PA6 + GF30 | PA66 + GF30 |
|---|---|---|
| Résistance à la traction | 140-160 MPa | 170-200 MPa |
| HDT (1,8 MPa) | 205°C+ | 250°C+ |
| Absorption de l'humidité | 1.0-1.5% | 0.8-1.2% |
Selection Summary
Choose Nylon 6 when:
- La résistance aux chocs est essentielle
- La sensibilité au coût est élevée
- Operating temperatures are moderate
Choose Nylon 66 when:
- Higher mechanical strength is required
- Elevated temperatures are expected
- Dimensional stability is critical
FAQ
When is Nylon 6 vs Nylon 66 — Engineering Plastic Selection Guide a good option?
Nylon 6 vs Nylon 66 — Engineering Plastic Selection Guide is a good option when fast iteration, complex geometry, low tooling cost, or low-volume production is more important than molded-part unit cost.
What should be checked before choosing Nylon 6 vs Nylon 66 — Engineering Plastic Selection Guide?
Vérifier la taille de la pièce, les propriétés du matériau, l'état de surface, la tolérance dimensionnelle, l'exposition à la chaleur, la direction de la charge et la nécessité d'un post-traitement.
How does Nylon 6 vs Nylon 66 — Engineering Plastic Selection Guide compare with CNC machining?
L'impression 3D permet de créer rapidement des formes complexes, tandis que l'usinage CNC est souvent plus performant pour les surfaces précises, les tolérances plus étroites et les matériaux de qualité.
What affects the cost of Nylon 6 vs Nylon 66 — Engineering Plastic Selection Guide?
Le coût dépend du matériau, du volume de construction, du temps d'impression, de la hauteur des couches, de l'enlèvement du support, de la finition, de l'inspection et du nombre de pièces dans la construction.
Lire la suite
- Nylon ou polypropylène : guide de choix des matériaux pour les applications techniques
- Acétal POM vs Nylon - Quel plastique technique convient le mieux à votre application ?
- Nylon vs PBT : Comparaison complète des thermoplastiques d'ingénierie
At a Glance
| Decision Point | PA6 | PA66 | Buyer Note |
|---|---|---|---|
| Impact / toughness | Strong | Strong | Compare actual part loading, not just resin family |
| Résistance à la chaleur | Bon | Usually better | PA66 often wins when temperature margin matters |
| Moisture response | Plus élevé | Also high | Conditioning will affect both grades |
| Best use | General engineering parts | Hotter or more demanding parts | Use the part environment to decide the grade |
Why Choose Nylon Plastic
Nylon Plastic can help buyers separate PA6 and PA66 decisions when the part needs a practical balance of heat, toughness and molding cost.
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