usually, also in first-rate mold solution co, ltd, our designer use integral embedded cavity design, that is to use high quality materials ( high-carbon steel or alloy tool steel) which are slightly than the external shape of the plastic parts ( wall thickness of sufficient intensity must be ensured) to make the cavity parts and embed them into the molding plate thereafter. The advantage is that the service life of the cavity parts can be ensured and meanwhile the material cost is reduced. Furthermore, it is easy and convenient to repair and replace the cavity parts if they are damaged. Actually, in core side, mold maker also can do like this.