Heavy-deburring brushes have a double stem and abrasive nylon single spiral bristles to remove excess material and smooth cross holes on all metals. Double-stem, single-spiral tube brushes have moderate bristle density and rigidity. Abrasive nylon bristles are embedded with a coarse material along the entire length that continuously exposes fresh abrasive for a consistent surface finish. Nylon bristles are flexible and suited for plastic, aluminum, brass, and copper. They also offer improved safety compared to wire filament bristles, which are sharp and may fall off during operation.