Stress on ABS Material

difficult to discern from your post what you are doing, but will make a couple of assumptions -

a) it sounds like you are injection molding your article - you could decrease the amount of molded in stress by increasing the number of injection points (and pay attention to where they are in the short versus long dimensions - shrinkage

b) it doesn't sound like you are annealing the product prior to additional value added activity (chrome plating) - perhaps annealing (raising the temperture above the point where the the material will relax and release molded in stress and then cooling again) will help

Good luck and let us know how you do -

Jim Wilson