Curve Cutter. Thanks to its unique saucerlike shape, the 7-inch Contoured Masonry Blade by Arcus can cut arcs with a radius as small as 15 inches. It can be used in circular saws and in tile saws with tilting heads, and its segmented diamond edge can be used wet or dry. An optional compass arm is recommended for use with a circular saw. The company also makes blades for cutting curves in wood and metal. The masonry blade costs $60 from the maker. Arcus, 502/495-2959. www.arcusblade.com