A spiral drill bit is a specialized drilling tool for rotary drilling rigs. It is also commonly used as a long spiral drill bit on rotary drilling rigs, or mounted on excavators for use as a modified spiral drill.
Different types of spiral drill bits are required depending on the geological conditions. Conical double-ended double-spiral drill bits are suitable for hard bedrock. Double-ended single-spiral drill bits are suitable for weathered bedrock, pebbles, and permafrost layers. Straight spiral drill bits (such as bucket-tooth straight spiral drill bits) are suitable for sandy soil and poorly cemented small-diameter gravel layers. Cutting-tooth straight spiral drill bits are suitable for hard bedrock or gravel layers.
In the construction of inclined anchor holes in foundation pits, spiral drill bits (twist drills) are a commonly used technique. In a real estate infrastructure project in Chizhou, Anhui, a Kongshan KS800 multi-functional anchor drilling rig equipped with a spiral drill bit was used for inclined anchor drilling. The construction parameters were: hole diameter 150mm, hole depth 14m, rock layer: soil, drilling angle 45°, and a construction efficiency of approximately 45m/h.