Interference Fit for Plastics

I think those issues are only resolved empirically as there are too many variables. (there are enough variable just in the molding process). Try to make the design as resistant to tolerances as possible (e.g, spring finger fits rather than just interferrence)
Injection molding tools should be made in a metal off (metal safe condition) and then adjustments made to suit.
Bear in mind that accelerated life testing of some sort will be in order as dimensions may change due to moisture absorption.

Del
(the above is based on limited experience of this subject, so pencil in the usual disclaimers)

There are three rules in injection molding; temperature, temperature, and temperature.

...and cycle time...and pressure, oh and don't forget temperature

ASK YOUR MATERIAL SUPPLIER!

The CTE of Nylon vs whatever metal you are using will determine the tolerances you will need.

If you have a 1/4" dia metal pin surrounded by plastic and cool it off too much you will probably crack the plastic.

ASK YOUR MATERIAL SUPPLIER!

Hmm...so such are to be solved locally eh, depending on the particular application etc. True, many variables. I was only hoping to avoid bending my back :P

And yes, I am trying to contact DuPont reg. this, if they have any such docs with them.

I did not expect suggestions this quick, thanks guys.

DuPont has excellent resources and design manuals, probably some of the best in the world. If you will be molding PA (nylon), remember that sharp inside corners are to be avoided as much as possible. Nylon's strength changes very much with its moisture content. If it dries out (desert use) it will shrink, adding stress as metal inserts will not shrink, and it will become more brittle. This is a bad combination. As it absorbs moisture, it becomes more ductile and expands. The electrical connectors may become loose. DuPont technical people have had a lot of experience with electrical connectors, so they should be able to help very much with your designs. You still will need to do testing to make sure the connectors will work in all service conditions.

GA...
Fillers like glass may improve the mechanical properties, although glass filled nylon doesn't have such a nice finish.
Del

Google, "Snap fit Guide," and you will have plenty to do.