Since 1915, Diamond Manufacturing has been providing original equipment manufacturers (OEM's), job shops, and architectural f ... irms with quality perforated material. Diamond Manufacturing is North America's leading and largest perforator. Headquartered out of Wyoming, Pennsylvania they have been offering tight tolerance perforation, fabrication, and finishing for decades from eight locations throughout the United States. Diamond is now apart of the Reliance Steel family since 2010. Reliance Steel & Aluminum Co. is a Fortune 500 company and has been named to the Fortune list of “The World’s Most Admired Companies”. read more