Wide-face heavy-cleaning brushes have two rows of carbon steel standard twist-knot bristles to remove paint, rust, and deep scratches from contoured carbon steel surfaces. Double-row brushes have an extra line of bristles to address wide surfaces and make additional direct contact with a workpiece. Standard twist-knot wire bristles are flexible and have rope-like, twisted wire along the length for use on irregular surfaces. Carbon steel bristles remove material at a high rate on iron, carbon steel, and wood.