The Down-the-Hole (DTH) drill bit is a type of bit designed to be used in conjunction with a DTH hammer; it couples with the hammer via splines to perform drilling operations. Widely utilized in construction sectors such as open-pit mining, water well drilling, tunneling, quarrying, and hydroelectric engineering, these bits offer numerous advantages, including the ability to drill deep, straight holes with large diameters and high efficiency. Based on operating air pressure, DTH bits can be classified into high-pressure and low-pressure types. Their face designs primarily include convex, flat, concave, and drop-center profiles, while the carbide inserts typically feature spherical buttons, ballistic buttons, or a combination of both arrangements. Driven by technological advancements, continuous innovations have been achieved regarding materials, bit body performance, and button retention processes, leading to the application of new materials such as polycrystalline diamond (PCD). In 2019, China issued the national standard GB/T 13344-2019, titled *Down-the-Hole Hammers and Down-the-Hole Bits*.
High-pressure DTH drill bits consist of a bit head and a bit tail tube; the tail tube is housed within the internal bore at the rear of the bit head. This tail tube is composed of a structural skeleton encased in a composite shock-absorbing body. Such bits exhibit excellent resistance to both high and low temperatures, as well as superior resistance to impact, bending, tension, and fatigue, thereby significantly extending their service life. High-pressure DTH bits are primarily employed in blast-hole drilling and water well drilling projects, finding extensive application in construction sectors such as mining, marble quarrying, and general drilling operations.