Drill Hulk carbide-tipped masonry drill bits are made from hardened steel body and carbide tipped head. 3/16-inch carbide-tipped masonry drill bits are designed for pilot hole in concrete, block and brick, then installing 1/4-inch concrete screws. Made in China You Will Get: 6 pieces of 3/16-inch x 5-1/2-inch carbide-tipped masonry drill bits with case. Notice: Check for reinforced concrete. Check for piping and cable routing. Grease the shank & remove residual materials. Warning: Drill bits can shatter during use. Always wear safety goggles and safety items when drilling.