Grounding Wires - Wire - The Home Depot View the Southwire Company - Solid Soft Drawn Bare Copper Grounding Wire Assortment $ 18 26 $ 18 26. Free delivery with $45 order. Set your store to see local availability Add to Cart. Compare. More Options Available. Southwire 50 ft. 6-Gauge Stranded SD Bare Copper Grounding Wire[PDF] Wire Size Selection Guide - Steven Engineering Grounding Connectors E4. Permanent Identification Wire Size Selection Guide To use this guide place your wire or cable in the appropriate circle to determine wire, outside diameter. The charts below indicate the approximate cable outside diameter or various electrical and communication cables.