Grav Co, LLC mass finishing industry leader and innovator in compounds, media and equipment since 1948. Grav Co LLC offers the industry's most complete line of mass finishing supplies. From ceramic, steel and plastic medias, powder and liquid compounds, to dry finishing medias such as treated cob meal and walnut shells. Grav Co offers a free process sampling in our fully stocked lab in Sturgis, Michigan. Send us your parts, we will process them in our lab and send back the finished parts, along with a written test report. You can then compare your current process with Grav Co's recommended equipment, media and compounds. Let Grav Co assist you with the best possible processing solutions at the most economical price.