After the body of the barrel has been formed, then the heads, or barrel-ends, must be made and fitted. Five or six head staves are fitted together with wooden dowels or stainless steel gudgeons (headless nails). Some cooperagess are now using a tongue and groove system. Then the head is cut to size, usually round but sometimes slightly oval in shape. Near each end of the body of the barrel, a groove, called the croze, is cut into the inside of the barrel. The head is cut at the edges so that it will fit into the croze.