LittleMachineShop.com Ball and Radius Turning Tool - Designed to cut round shapes or curves in brass, aluminum, steel or plastic on your own small lathe (2569) - - Amazon.com
Radius tools
radius rod builder tool — Walker Racing Development
Kraft 6" x 4" 3/4" Radius Inside Curb Tool - White Cap
Eagle Rock - 1/2, 13 and Up Inch Lathe Swing, Rocker Tool Post Compatible, Concave Lathe Radius Cutter - 08657355 - MSC Industrial Supply
Clay Radius Shaping Tool Set - Silica Systems Inc.
Bon Tool 6 in. x 5 in. Curb Tool Edger with 3 in. Radius and Wood Handle 12-414 - The Home Depot
LATHE TOOL BIT CARBIDE TIPPED RADIUS POINT RIGHT SIDE 1/2" x 1/2" x 3.1/2" SHANK | eBay
Bon Tool 9 in. Ornamental Tool Radius Shaping 83-163 - The Home Depot