HD Supply Utilities: Specials & What's New - Serving Electrical Utilities & Contractors Since 1978. HD Supply, utility, grafton utility, canada, colborne, electrical, utility, supply, company, distribution of, wire, transformers, arresters, fusing, switching, poleline, streetlighting, poles, connectors, underground, loadbreak, anchors, terminations, splices, line, construction, transmission, hardware, high voltage