We manufacture light fixtures from 20 ga. stainless steel. We very much like the appearance of the glass bead blast finish. However we are having trouble with the material warping from the blasting. We tried turning down the pressure, but that just make it take longer to get the desired finish and it still warps. Do you have any suggestions short of using heavier material.

What size of bead are you using? You might try a smaller glass bead size or ceramic bead.

Are you peening the fixture all over, or just on one side? If you are only peening one side, then peening the opposite side may cause shape recovery.