These Carbide Burs Straight Fissures heads are made with high quality fine-grain tungsten carbide, which produces a blade that is sharper and wears longer compared to less expensive coarse grain tungsten carbide. Blades made of fine grain tungsten carbide, retain shape even as they wear. Less expensive, large particle tungsten carbide dulls quickly as the large particles break from the blade or cutting edge. Many carbide manufacturers use inexpensive tool steel for the carbide bur shank material. For shank construction, SS White uses surgical grade stainless steel, which resists corrosion during sterilization processes used in the dental office.