These brushes are designed to fit into the smallest holes to clean out residues, oil, grease, surface rust and oxidation. They are especially useful in plastics machining to deburr parts, and in plastic injection molding operations to clean out plastic residue, resins and gassing. The brushes are a thick stiff durable nylon composite fiber that holds their shape well and can be used for multiple cleanings. The brushes are available in many sizes from .017 " to 1.25" in diameter with lengths up to 4". They have a threaded end that may be screwed into our available handle, or can be used with a drill or fixtured onto a CNC machine. Customers have reported great savings in time and money in deburring operations. In some cases up to 40 hours per job. Price breaks are available for ordering by the dozen. Please note: Warning: This contains a chemical known to the State of California to cause birth defects, reproductive, or other physical harm. Wear gloves or wash hands after handling. For further information go to www.p65warnings.ca.gov.