Need help with material selection - injection moulding nylon

[Wing Commander]

Hi all

I need some help please with material selection for a part, which I need multiple tens of thousands made.

The part can be described as a peg which attaches to a chain, within a machine. We have 3D printed some prototypes in PA12 Nylon but, despite my understanding of the material being relatively resistant to fracture, we are noticing the 3D printed versions are fracturing when impacted.

The 3D printing is the cheap prototype stage before we invest in tooling for injection moulding the parts, from the same PA12 Nylon material.

What I am unsure on is:

Would an injection moulded part using the same material be less prone to fracture? Or have we got the wrong material here?

Ideally looking for someone with materials experience to guide us on this - happy to pay for this service if anyone can recommend a suitable consultant etc

Thanks

[Wing Commander]

As is typically the way, once you put something out to the world for their help, all gets sorted.

We've seemingly solved the issue by locking in the design, and agreeing with tooling manufacturer that we can test multiple material types on the same tooling

[zbc]

If it helps at all I would expect you to get fewer cracks from a manufactured part rather than a 3D printed one dependent on specific design.

[wilksy61]

Don't forget that different materials may have different shrink rate characteristics which could alter final dimensions.