Insert, or partial tooling, is a concept that allows our customers to get into an injection molded part with minimal tooling expenses. An insert tool consists of just a cavity (or even up to 8 cavities) and a means of ejecting the part from the mold. These partial tools are usually made of mild steel but can be made from harder materials like stainless steel or P-20. These cavities are then  placed in a UPI owned mold base for use in a conventional molding machine.  This process can save THOUSANDS of  $$ when prototyping or for low volume molding.