Dremel 9936 Cutter-Tungsten Whl 3/4In Fast-cutting, sharp teeth for greater material removal. Use on fiberglass, wood, plastic, epoxy, rubber, laminates, particleboard and ceramic tile. For best results, insert the accessory bit all the way into the tool and then back it out slightly before tightening down. This provides plenty of shank for the collet or chuck to hold onto the bit. Secure objects to a stable surface while working. Use the sides of the cutter (rather than the tip) for effective cutting. The tip cuts poorly and can break under pressure. Use higher speeds for hard woods, slower speeds for metals and very slow speeds for plastics (to avoid melting at the point of contact).