The type of diamond drill bit (expander), the hardness of the matrix, the quality, hardness, and concentration of the diamond, and the structural characteristics of the drill bit (including the shape of cracks at the bottom of the drill bit such as rectangular, circular, semicircular, stepped, etc.) are physical and mechanical properties of rocks.

　　Currently, with the increasing number of newly developed high-speed rail, subway, and railway lines, drill bits are becoming more prominent in daily life, particularly in the auxiliary area of drill bits.Diamond drill bit(Expander) selection and use are key factors in improving effectiveness and lifespan.

　　

　　(1) Accurate and reasonable selection of diamond drill bits (reamers).

　　The type of diamond drill bit (expander), body hardness, diamond quality, hardness and concentration, as well as the structural characteristics of the drill bit (including bottom crack shapes such as rectangular, circular, semicircular, stepped, etc.) are related to the physical and mechanical properties of the rock.

　　The principle for selecting diamond drill bits is: for rock layers that are dense in structure, fine in particles, high in hardness, and strong in compressive strength, soft-bodied, low-water-content, low-concentration diamond drill bits (expanders) should be chosen to ensure exposure of diamonds during drilling and prevent them from falling off. Conversely, for highly abrasive but not hard rock layers, the quantity and concentration of diamond drill bits should be increased accordingly to enhance the hardness of the diamond drill bit (expander) body.

　　(2) Accurate and reasonable use of diamond drill bits (reamers).

       

　　The principle for using diamond drill bits (expanders) is 'first large outer diameter with small inner diameter; then small outer diameter with large inner diameter', while also grouping and alternating their use.

　　Diamond composite drill bits are mainly used for drilling existing rock layers such as limestone, shale, and low-hardness coarse sandstone. Compared to diamond composite drill bits, this type has a faster foot speed and higher wear resistance. It is an ideal choice for drilling in soft rock layers. It should be noted that what the market needs are products with high drilling efficiency and cost-effectiveness. No manufacturer can rely solely on price to establish a foothold in the market. The drilling efficiency of a bit—its particle efficiency—is an important indicator reflecting drilling levels. The hardness of a diamond bit—whether its body hardness is compatible with the rock layer—is key to determining particle efficiency. Before drilling holes, it is necessary to select a bit with appropriate base hardness.

　　The development of diamond drill bit technology has a history of over 20 years; however, currently the pace of design improvements for diamond drill bits is faster than ever before. As the application range of diamond drill bits expands further, people's expectations for them also increase; thus designers need to continuously strive for innovation to optimize designs and develop new drills. Currently, research on diamond drills has shifted from treatment-oriented to prevention-oriented.

　　From both domestic and international drilling trends perspective under existing drilling technology conditions it has become very difficult to significantly increase drilling speed using roller cone bits. Especially in special formations like slopes where mechanical drilling speed is affected by parameters leading to lower rates which greatly impacts construction cycles.Diamond drill bitWith advantages such as high mechanical drilling speed, multiple feet design longevity significantly improved rates for deep well usage among others. The use of diamond drills shows a trend towards accelerating exploration development.