A drag bit is a drill bit usually designed for use in soft formations such as sand, clay, or some soft rock. However, they will not work well in coarse gravel or hard rock formations. Uses include drilling water wells, mining, geothermal, environmental and exploration drilling. Whenever possible, they should be used to drill pilot holes because they produce cuttings that are easiest to log.
Step-type drag bits come in a variety of wing counts, steps, and sizes to accommodate drilling in a variety of formations, from sand and clay to shale, limestone, gravel, and more.
Regular quantity of wings:
3, 4, 5
3 7/8 to 26
2 3/8 reg pin, 2 7/8 reg pin, 3 1/2 reg pin , 4 1/2 reg pin, 6 5/8 reg pin, 7 5/8 reg pin.