GLASS AND TILE BITS Two types of bits are available for glass and tile drilling. Some glass-and-tile bits from have a spear-pointed carbide tip to reduce bit wander and bit walking. The carbide tip prevents bit crack- ing when using with hard materi- als. Available in a range of sizes, these spear bits provide smooth, accurate drilling in ceramic tile, marble, china, mirrors and glass. These are a good choice for drilling fastener holes in bathroom tile or wall mirrors. A second concept for glass and tile, diamond-grit drill bits utilize a circular cutting edge, like a hole saw, to power through class 5 tile, marble, porcelain, granite, slate and glass quickly and cost effec- tively. To use freehand, position the bit at an angle to pilot the hole. Slowly begin the edge of the hole and gradually center the bit directly above, drilling down to eliminate the risk of drill-bit wander. As the bit drills through material, the hol- low barrel of the bit creates a core that helps guide the drill and elimi- nates skating. These “wet drill bits” must be water-cooled when in use. MASONRY BITS Masonry bits are a variation of the twist-bit design and are typical- ly used with a hammer-drill for its high-impact action. They feature a chisel-like tungsten carbide tip to break up stone, brick or concrete, while the flutes pull back the chipped material. Because these bits occasionally get jammed with crushed masonry, it’s best to oper- ate the hammer-drill with a pump- ing action. Masonry bits are excel- lent for installing wiring and plumb- ing in existing structures.
Masonry bits are a variation of the twist-bit-design and are typi- cally used with a hammer-drill for its high-impact action. Photo © Bosch. Bosch Glass & Tile Bits feature a spear point to reduce bit wander and a carbide tip to prevent bit cracking when using with hard materials. Photos © Bosch.