Doyle Shamrock Industries was established in 1975 by Michael A. Doyle. Doyle Shamrock Industries is a full service plastic injection molding and tooling corporation that is located in Holland Ohio. We have two manufacturing locations plus an off-site warehouse & distribution facility encompassing 200,000 square feet of space. Our goal at Doyle Shamrock Industries is customer satisfaction! We are ISO/TS 16949:2009 quality certified, and we are ISO 14001:2004 certified (Environmental Management System).