Ranging in price from $2 to about $200, depending on size and quality, carbide-tipped masonry bits can be expensive. What's more, the cost to the contractor multiplies, as these consumable items wear out and need to be replaced. So before buying another drill bit, masonry contractors should educate themselves on the features and benefits of various types. CHOOSING THE DRILLING TOOL Masonry contractors prefer either hammer drills or rotary hammers. The hammer drill easily bores through brick, block, and soft-aggregate concrete. Rotary hammers can drill through hard stone and concrete, as well as brick and block. SHANK SHAPE VARIATIONS Don't be confused by the strange designations: SDS-plus, TE, spline, and straight-shank. All refer to the shape of the shank that fits into the chuck or nosepiece of the tool; the terms do not indicate special functions or quality levels. ANALYZING QUALITY Three features should be given special attention-the brazing, the steel used in the body of the bit, and the fluting. Masonry drill bits have tungsten carbide tips. In the manufacturing process, a carbide tip is soldered, or brazed, to the bit under high heat. If the brazing is of poor quality, the carbide tip can fall off the bit during drilling. Because bits have to be strong, the best bits are made of high-grade steel, annealed (heated, then cooled) to prevent damage. Very important, a bit's fluting is what removes the dust from the hole. A bit's longevity depends on its size, the degree of use, the hardness of the drilled materials, and how well the bit is maintained.