Short answer is 3 degrees draft is pretty safe most of the time, assuming you have some texturing. A shallower texture means you can get away with a bit less dr

Short answer is 3 degrees draft is pretty safe most of the time, assuming you have some texturing. A shallower texture means you can get away with a bit less draft and vice versa. The reason is that you want the tool to release the piece and not get bound up. Shape and cooling also factor in, but for simple box type shapes with no large cutouts, this is usually predictable.