In geotechnical engineering operations, the efficiency and cost of drilling directly impact the overall project timeline. Particularly in medium‑hard rock formations, conventional drill bits often suffer from slow penetration rates and short service lives. To address these challenges, Luoyang Jinlu has introduced its PDC coreless drill bit, which, backed by a suite of proprietary technological advantages, has become an ideal solution for enhancing the overall performance of drilling operations.

01 Product Overview: High-Efficiency, Durable Coreless Drilling Tool

The PDC non‑core‑bit is an integral drill bit that uses a polycrystalline diamond compact (PDC) composite insert as its primary cutting material, primarily intended for full‑hole drilling operations where core recovery is not required. When paired with hydraulic or pneumatic drilling rigs, it can efficiently perform drilling for gas drainage holes, water‑discharge holes, geological exploration boreholes, and various other engineering applications.

Figure 1: Product image of a centerless drill bit

These drill bits typically use alloy steel as the matrix material for the bit body, with wear‑resistant gauge pads brazed to the exterior to protect the bit body from abrasion caused by the formation and to maintain a consistent bore diameter. During operation, PDC cutters fracture the rock through shear action. This combination gives the drill bit significant advantages, such as high penetration rates and extended service life.

02 Diverse Product Design: Meeting Varied Geological Drilling Requirements

For varying geological conditions, Luoyang Jinlu’s PDC core bits offer a range of cutter‑crown geometries and composite‑insert types for customers to choose from. Engineering personnel can select the most suitable bit type based on the specific characteristics of the rock formation—such as soft to medium‑hard formations and the presence of abrasive constituents—to achieve optimal drilling performance.

Characteristics of different crown shapes:

Figure 2: Crown shapes of centerless drill bits (from left to right: flat top, rounded corner, and concave)

Characteristics of different composite insert types:

Figure 3: Types of composite tiles (from left to right: Mercedes tile, chamfered tile, flat tile, and ridge tile)

03 Core Product Advantages: A Breakthrough in the Synergy of Long Lifespan and High Efficiency

Figure 4: Test screen from a mine in Guizhou Province

Taking the underground application at a coal mine in Guizhou as an example, the Luoyang Jinlu φ94 four-wing arc‑shaped centerless drill bit has drilled a cumulative total of 27 holes in sandstone, coal seams, and limestone, with individual hole depths ranging from 16 to 48 meters, for a combined drilling length of 886 meters. Meanwhile, other products still maintain a service life of approximately 400 meters.

On the market, another brand’s individual product has accumulated 10 boreholes, with each hole ranging from 19 to 46 meters in depth, totaling 293 to 370 meters of drilling, during which composite inserts were observed to fracture and crumble.

Figure 5: Coreless drill bits after drilling operations (left: Luoyang Jinlu; right: other brands)

In this operational test, Luoyang Jinlu’s products demonstrated an average service life more than twice that of competing brands. With their exceptional wear resistance, high drilling efficiency, and broad compatibility across various rock formations, Luoyang Jinlu’s PDC core bits are increasingly becoming the trusted choice for numerous mining and engineering companies seeking to enhance the productivity and cost-effectiveness of their drilling operations.