The bearing surface of mold and the boss: the whole bottom of plastic parts as support is not reasonable, because the plastic parts slightly warped or variant will make the bottom. Usually used in projecting frame support or sole supporting.
  When the plastic bottom is provided with the reinforcing rib, should make the reinforced rib and the supporting surface is 0.5mm height.
  The boss is used to enhance the protruding part, holes or assembly. General speaking, the boss should be located in or near the edge of the side wall of the workpiece, the height should not exceed two times of the diameter, and should need to draft enough, to avoid the thin and high boss should consider strengthening reinforcement. When the assembly of parts when the boss, boss should have sufficient strength, should avoid boss turning point mutations and small size.