I've been working on a design that requires a plastic snap feature. I've assumed up to this point that the material will be injection molded ABS, with material properties I pulled off of matweb.
After several dozen iterations on the design, I've pushed the geometry of the snap as far as possible give the geometric conditions of the feature and I'm right on the edge of acceptable (Factor of safety of ~1.1). If my loading conditions end up being too conservative or any features of my part come out slightly out of spec I could easily have parts that fail. I'd be much more comfortable with an FOS up above 1.8.
Ideally I'd like to lower the Youngs modulus of my material and I'm wondering if ABS can have its material properties 'toyed' with by using a different formulation of the plastic. Also, how consistent are material properties of injection parts?