About Us  Keystone Constructors, Inc., headquartered in Gaffney, South Carolina and provides construction services throughout the southeast. Keystone is a full  service company of professionals who serve industry through construction application and construction management. Our business focus is on the Mechanical and Electrical construction, upgrades and maintenance of companies that have heavy process requirements. Industries served include chemical, automotive, food, textiles, power and industries with process application needs. Our Mission To create value for our clients by constructing cost efficient projects which meet or exceed expectations for quality, schedule and performance.   experience commitment solutions