ATD Tools (8320 20-Piece Twisted Wire Tube Brush Set All brushes have 1/4 inches hex shaped quick-disconnect shanks for easy and quick changes Stainless steel brushes are stiff and aggressive and can be used in tough spots for heavy duty cleaning Brass brushes are less abrasive and will not scratch harder metals Nylon brushes are perfect for light duty cleaning Includes 6 brush sizes each in stainless steel, brass and nylon bristles for different jobs