The suitable geological conditions for spiral drill bits vary depending on the type and structure of the bit. Soil spiral drill bits are suitable for soil layers above the groundwater level, sandy soil layers, dense sand layers containing a small amount of clay, and gravel layers with small particle sizes. Rock spiral drill bits are suitable for weathered bedrock, well-cemented gravel and pebble strata, and permafrost.
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. Among straight spiral drill bits, the bucket tooth type is suitable for sandy soil and poorly cemented small-diameter gravel layers; the double-ended single-spiral type is suitable for sandy soil and soil layers; the single-ended single-spiral type is suitable for poorly cemented large-diameter pebbles, clayey soil, and hard clay. Cutting tooth straight spiral drill bits are suitable for hard bedrock or gravel.
