One of our biggest EDM distributors for North America is Single Source Technologies (SST). When it comes to EDM technologies and supplies, they are an excellent resource for consultation and consumable inventory. We highly recommend you check them out.
SST offers a full line of graphite materials for any EDM need, including flat plates, rounds, and also roto-bore electrodes for large diameter EDM hole machining. The company provides inventory of multiple material grades from POCO Graphite, and also its own performance/economy grade VersaGraph.
The VersaGraph200 is a medium-grade, general-purpose material that is suited for large detail machining, or burns that require high amperage.
The VersaGraph3 is a fine-grade graphite material that is well suited for small details that require higher accuracy and less electrode wear.