The Plastics Industry Association (SPI), now known as the Plastics Industry Association (PIA), classifies molds according to the number of cycles they are expected to run. These classifications indicate the quality of the mold but are not a guarantee of quality as other factors can affect the life of the mold. You may see these referred to as SPI or PIA classes.
Class 101 - These molds have been manufactured in over a million cycles - with extremely high yields. These molds are the most expensive and are manufactured with the highest quality materials. Tool structural parts must have a hardness of 28 Rc and the cavity and core must have a minimum hardness of 48 Rc. Areas that move relative to each other should have a hardness difference of at least 4 Rc. Other mold details such as heels, wedges, wedges and slides should be made of hardened tool steel. There are additional requirements for ejection, sliding, temperature control and parting line locks.
Grade 102 – These molds are capable of up to 1 million cycles – medium to high production. The material hardness requirements of tool structural parts, cavity and core are the same as that of grade 10. Other functional parts shall be made of heat-treated steel. The most notable difference between grade 101 and grade 102 is that, depending on the expected part count, sliding wear plates, guided ejectors, corrosion-resistant plating chambers, and temperature-controlled channels may not be required.
Grade 103 - These dies have a maximum life of 500,000 cycles - Medium production. Formwork bases must have a minimum hardness of 8 Rc and cavities and cores must have a minimum hardness of 28 Rc.
Class 104 - These molds are manufactured in 100,000 cycles or less - Low-volume molds. This mold works best with non-abrasive materials. Formwork and cavities can be made of mild steel or aluminum.
Class 105 – These dies are intended to last no more than 500 shots and are typically used for a limited number of prototypes. They are built in the cheapest way possible and may use cast metal, epoxy, or other materials.
