When a design calls for a plastic that acts like metal, engineers turn to Nylon (Polyamide). In the molding world, PA6 and PA66 are the two heavyweights. Nylon is famous for its “tough-as-nails” reputation—it has high mechanical strength, incredible wear resistance, and a natural slipperiness that makes it perfect for moving parts.
The main difference? PA66 is the high-performance athlete (better heat resistance and lower moisture absorption), while PA6 is the versatile all-rounder (easier to process and slightly more impact-resistant).
| Property | PA6 (Annealed) | PA66 (Annealed) | Why it Matters |
| Tensile Strength | 50 – 70 MPa | 60 – 85 MPa | High load-bearing capacity |
| Melting Point | ~220°C | ~260°C | PA66 handles higher engine-bay temps |
| Molding Shrinkage | 0.7% – 1.5% | 0.7% – 2.0% | Significant shrinkage; needs expert tooling |
| Impact Strength | 5 – 12 kJ/m² | 4 – 10 kJ/m² | Absorbs vibration and shocks |
| Water Absorption | 2.5% – 3.0% | 2.0% – 2.5% | Affects dimensions and strength over time |
The most important thing to know about Nylon is that it is hygroscopic—it loves to drink water. After a part is molded, it will actually absorb moisture from the air, which makes the plastic tougher and more flexible but slightly increases its size.
In Injection Molding, Nylon is the king of “under-the-hood” automotive parts, power tool housings, and industrial gears. It has a natural self-lubricating quality, meaning gears made of Nylon often don’t need external grease to run quietly and smoothly.
Pro Tip: If your part needs to be “rock solid” and never bend, we often add 30% Glass Fiber (GF30). This transforms Nylon into a structural powerhouse that can replace die-cast aluminum in many engine and industrial applications.
Is your part replacing a metal component or working in a high-friction environment? I can help you decide if a glass-filled PA66 or a toughened PA6 is the best choice for your mechanical requirements.
Contact us to evaluate manufacturability, tolerances, and cost for your specific application.
We will contact you within 24 hrs, please pay attention to the email with the suffix “@dewintech.com”. Your privacy is safe, we won’t use your email for any other purposes. Download NDA
