A brush block, or back, is manufactured through the drilling of holes and insertion of fill tufts into those holes. Commonly made out of plastic, metal, or wood, block brushes can be manufactured with any type of filament. Brush fills may range from hard to soft in stiffness, and large to fine in diameter. The uses for block brushes are virtually limitless. The fill material used in the brush can come from natural, synthetic, or metal sources. General applications for any Block brushes are: Applying, Pushing, Removing, Cleaning, Spreading, or acting as a Barrier. The large flat scrub brushes in this category are very effective at reworking large printed circuit boards, or for general cleaning over larger surfaces, and for cleaning and deburring metal parts, as well as removing residue, metal fillings, paint, and coatings.