SM-4 Pointed Cone Shape - Premium Double Cut Tungsten Carbide Burr 1/4" ShankCategory: Flame Shape Carbide BurrCarbide Rotary Burrs are used for cutting, shaping, grinding and for the removal of sharp edges, burrs and excess material (deburring). Tungsten Carbide burrs can be used on most hard materials: metals including steel, aluminum and cast iron, all types of stone, ceramic, porcelain, hard wood, acrylics, fiberglass and reinforced plastics. Ideally carbide burrs are used in Air Tools i.e Die Grinders, Pneumatic rotary tools and high speed engravers. Carbide burrs commonly come in three cuts; single cut, double cut & diamond cut; we offer DOUBLE CUT. Double cut or cross cut carbide burrs tend to be used on ferrous and non ferrous metals, aluminum, soft steel and also for all non-metal materials such as stone, plastics, hard wood and ceramic. Double cut or cross cut (2 flutes cut across each other) will leave a slightly smoother finish than single cut due to producing smaller chips as they cut away the material. Use for medium stock removal, deburring, finishing and cleaning. A double cut carbide burr is the most popular cut and will see you through most applications. Making a decision on what shape to use will depend on the profile or cut you are looking to achieve. These different shaped burs will get into many a nook and cranny and produce some interesting profiles. The shape if the burr is in the product name i.e. SD, SC SE. POINTED CONE SHAPE (SM) - Good for rounded edges and surface finishing in difficult to reach areas or tight and narrow angles and contours. The speed at which you use your carbide bur in your rotary tool will depend on the material you're using it on and the contour being produced but it's safe to say you do not need to exceed speeds of 35,000 RPM. If the burs are chipping easily this could be due to the speed being too slow. However, it's ideal to start the bur off slow, increasing the speed as you go along. High speeds will prevent clogging in the flutes of your burs. As with all drill bits and burrs, let the burr do the work and apply only a little pressure otherwise the cutting edges of the flutes will chip away or become smooth too quickly, reducing the life of your burr. When using your carbide burr try not to keep it still for too long as this will prevent the burr from digging and jabbing into your material causing unsightly marks and roughness. End on an 'up' stroke for a smoother finish to your work. Helpful note: Using a carbide burr on Soft Cast iron is a great way to de-clog them.