These V-Groove insert CNC router bits are specially designed specifically for applications including mitre folds, sign making and lettering. These cutters are innovatively designed with a high grade solid carbide insert knife, which can be rotated as the knife shows signs of wear, to benefit from a new cutting edge. The advantages of using insert tools include: extended tool life, easy replacement of dull knifes, and the use of harder grades of carbide. A secure knife locking system ensures maximum safety and maintains cutting accuracy. These cutters are excellent for cutting the following materials: Aluminum, Brass, Bronze, Copper, Gold, Silver & Carbon Fiber (Engraving Only) Acrylic/Plastic Composites Composite Decking Epoxy (Epoxy Resins) Foam High Density Polyethylene (HDPE) Laminate Melamine MDF/HDF PVC Sign Board Solid Surface Veneered Plywood Wood Xanita® Board 20lbs High Density Urethane Suitable for use with CNC Routers and shouldn't be used with a handheld router.-bg