Nylon 6 vs. Nylon 66: What's the Difference?

Find out which material makes the most sense in your application

You’re considering nylon for metal replacement because it can create parts that are durable, strong, yet also lightweight. But do you know which type to use? The two most popular grades of polyamide, also known as nylon, are type 6 and type 66 (sometimes seen as PA6 and PA66). Overall, they are fairly similar, but each has distinct benefits in specific applications. Nylon 6 processes at a lower temperature and has a lower mold shrinkage. The material itself is lightweight, has a lustrous finish, and is ideal for applications in which toughness, impact resistance, and surface finish are important. Some common applications of nylon 6 include:

  • Automotive components
  • Firearm components
  • Circuit Breakers
  • Pulleys and gears







Conversely, nylon 66 has a higher melting point, making it suitable for higher temperature applications. This material has improved stiffness, as well as higher tensile and flexural modulus, so it’s a good choice for applications in which wear and short-term heat resistance are important.

Due to its high melting point and durability, common applications of nylon 66 include:

  • Battery modules
  • Bolts and fasteners
  • Recreational equipment
  • General purpose housings







Nylon is a great option for metal replacement. The automotive industry relies on it, especially in under-hood components, to improve fuel efficiency, increase design freedom and reduce costs. Need proof? See how Avient helped one manufacturer switch from steel to nylon.


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Nylon 6 vs. Nylon 66:What's the Difference?

Whether you're looking to learn more about the history, performance or processability of the two most popular forms of nylon, Avient has you covered.

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