The Microplane® Flexible Rasp Blade is best for smoothing convex surfaces and rounding sharp edges. If it is stretched tight in a hacksaw frame, it is flat and fast cutting. If the frame tension is decreased, the blade will bend slightly around a convex surface for a smooth blended cutting action. These highly effective and long-lasting blades, designed to fit into a standard 300mm hacksaw frame, are made in the USA from high grade stainless steel.