LMT Belin - 13040J 4mm Cut Diameter Upcut Router BitBelin Upcut Router Bits are designed to deliver an excellent cut finish to most types of rigid plastic materials such as acrylic, polycarbonate, PVC, nylon, etc. They are also very effective for use on woods and foams. Cut Diameter: 4mm Shank: 6mm Cut Length: 22mm Overall Length: 60mm Flute Type: Upcut The upward spiral geometry ejects swarf and dust toward the top of the cutter, making waste material removal easy with a quality extraction system.