Material focus
Nylon 66 selection, applications, and sibling resin routing on this page.
Nylon 66
Nylon 66 Injection Molding: Properties, Applications and Design Guide
Nylon 66 (PA66) is the default engineering polyamide for metal replacement in automotive, industrial, and electrical hardware.
Nylon 66
When to specify Nylon 66
How procurement and design teams use Nylon 66 on injection molded programs.
Nylon 66 (PA66) is the default engineering polyamide for metal replacement in automotive, industrial, and electrical hardware. Glass-filled grades dominate when modulus and heat deflection must stay high in thin sections. Like PA6, PA66 must be dried and kept dry before molding to avoid splay and property loss. At NetProto, programs run from first-article validation through production on one hardened steel tool with no minimum order quantity. Upload CAD on the instant quote platform for DFM feedback before tooling release. For gears and sliding parts where moisture uptake is the concern, see Acetal (POM) .
PA66 vs PA6 is the usual split. Choose PA66 when heat and stiffness lead, and PA6 when thin-wall fill matters more. See the Nylon 6 vs Nylon 66 comparison .
Key traits
Why buyers specify Nylon 66
Engineering and sourcing highlights. No NetProto processing numbers on this page.
Sourcing
Grade and compliance context travels with CAD on the instant quote platform.
Program fit
First articles through production on one steel tool, no MOQ.
NetProto platform
Instant CAD quoting and DFM feedback before tooling release.
Tooling lead time
10 business days on qualified programs, depending on part size and complexity.
Common grades
Common Nylon 66 (PA66) grades by use case
Pick one of these on the instant quote, or name any other commercial grade in the RFQ notes.
| Use case | Example grade | Typical parts |
|---|---|---|
| General purpose | Zytel 101F | Connectors, automotive fasteners, machinery and industrial parts |
| Super tough / impact | Zytel ST801 | Sporting goods, furniture, impact-loaded housings |
| 33% glass fiber | Zytel 70G33L | Under-hood auto, electrical components needing high stiffness |
| Flame retardant, 25% GF | Zytel FR50 | Electrical and flame-rated structural parts |
| Heat stabilized | Zytel 103HSL | Continuous-use temperature and wear-resistant parts |
| Mineral filled (low warp) | Minlon 10B40 | Large flat structural parts and stiff housings |
Applications
Where this resin shows up on BOMs
Typical molded parts and what to specify on the purchase order.
| Application | Why this resin | Specify on the PO |
|---|---|---|
| Under-hood brackets | Higher heat than PA6 or PP | GF%, heat, fluid notes |
| Electrical connectors and headers | Flame-rated grades available from suppliers | FR filter + supplier documentation |
| Industrial levers and housings | Stiffness with GF | Wear or impact callouts |
RFQ
Ready to quote? Have this information ready
Not sure whether the BOM should say PA66 or PA6? See the comparison above. Prepare these details, then upload CAD on the instant quote platform.
Confirm PA66 vs PA6 on the BOM.
Specify GF loading and color.
Define drying and packaging if parts are dimensionally critical.
Commercial grade, or the use case to match (33% GF, flame retardant, super tough, heat stabilized)
Expected annual volume (helps cavity and tool planning)
Optional: target piece-price band for sourcing discussions
Next step
Upload CAD for an instant quote
Grade not finalized? Note Nylon 66 on the RFQ and attach environment notes.
Compare and explore
Related guides
Pairwise comparisons and sibling material pages.
Materials library
Browse all resin guides.
Materials library
Glass filled nylon
30% GF guide.
Glass filled nylon
Glass filled vs unfilled
Fill routing.
Glass filled vs unfilled
Reading a material datasheet
What the TDS (Technical Data Sheet) values mean for a molded part.
Reading a material datasheet
Specify resin grade on an RFQ
How to write grade, color, and fillers so the quote matches the part.
Specify resin grade on an RFQFAQ
Nylon 66 injection molding FAQ
Does PA66 always need glass?
No, but many structural BOMs specify GF15 to GF35 for stiffness.
PA66 vs metal?
Good for weight reduction when creep and temperature are within the resin window.
Can I switch from PA6 to PA66 in the same mold?
Only after validation. Shrink and fill differ, and so does the processing window. A mold cut for PA6 is not assumed to run PA66. Those values stay on each supplier datasheet.
What is the minimum order quantity for molded parts at NetProto?
NetProto has no minimum order quantity on molded parts from your production tool. Upload CAD on the instant quote platform to scope tooling and part pricing for your volume.
How do I quote this resin without a final grade selected?
List the resin family on the RFQ, attach environment notes, and upload CAD. Engineers narrow grades during DFM review.
Next step
Quote Nylon 66 parts with your CAD
Upload geometry and list Nylon 66 or the target grade on the instant quote platform.