Coi Rubber Products

Coi Rubber Products, Inc. is a U.S.-based rubber manufacturing and distribution company headquartered in Diamond Bar, California, with operations and production capabilities extending into Asia, including China. Founded on a vision of engineering precision and service excellence, the company specializes in custom rubber molding, extrusion, and sealing solutions for the automotive, industrial, and OEM sectors.
With over a decade of steady growth, Coi Rubber has evolved from a niche importer into a vertically integrated manufacturer offering full-spectrum rubber product design, prototyping, tooling, and mass production. The company’s strengths lie in its ability to combine domestic engineering expertise with global manufacturing efficiency, enabling competitive pricing without compromising quality or lead time.
Coi Rubber’s product range includes:
Automotive rubber components (gaskets, seals, mounts, bushings)
Custom extrusions for doors, windows, and weatherproofing applications
Industrial vibration and noise isolation parts
Custom OEM components developed to customer specifications
The company’s facilities maintain rigorous IATF 16949 certification standards, ensuring compliance with global automotive quality systems. Its strategic partnerships across Asia and North America enable robust supply chain resilience, JIT (Just-In-Time) logistics, and technical support tailored to customer needs.
Under the leadership of David Chao, President & CEO, Coi Rubber has built a reputation for reliability, engineering integrity, and customer-centric service. With continued expansion — including the acquisition of its new Pomona, CA headquarters and warehouse — the company is positioning itself for the next phase of growth: deeper automation, enhanced domestic capabilities, and a legacy of innovation-driven sustainability.