Four Process Ltd.

Four Process is a precision plastic injection molder that supports customers from concept through prototype, production, and inventory management. We specialize in tight-tolerance parts for critical applications and work with manufacturers that depend on consistent quality, reliable delivery, and clear communication.

Our ISO 9001:2015 certified, new, modern facility in St. Louis includes clean room capability, a full quality lab, robotics, automated material handling, 85- to 500-ton presses, and has room to grow. We provide insert molding, over molding, hot and cold runner systems, sonic welding, adhesive and solvent bonding, testing, and tooling support. Our team also handles assembly, component sourcing, specialized packaging, custom inventory programs, and transfer or reshoring projects.

For more than 50 years, our work has been guided by the four principles that gave Four Process its name: Communication, Honesty, Value, and Reliability. Veteran founded, woman owned, and family run, we have been recognized in Plastics News and Plastics Business Magazine. We are a partner for manufacturers who need precision and consistent performance.