Overview of Rock Drilling Tools for Drill Jumbos in China
Overview of Rock Drilling Tools for Drill Jumbos in China
Since hydraulic drill jumbos were introduced into major Chinese tunnel projects in the mid-1980s, demand for matching rock drilling tools has continued to grow. The development of drill-jumbo tools has become an important route for improving the overall capability of domestic drilling-tool manufacturers.
Main Product Categories
China’s drill-jumbo tool market includes four primary categories: underground development drilling tools, underground mining drilling tools, underground anchoring tools, and surface hydraulic drill-jumbo tools.
Underground Mining and Development Tools
Large underground metal mines commonly use fully hydraulic mining rigs with T38 or T45 threaded MF extension rods, mining drill rods, and threaded button bits in common diameters such as 76 mm and 89 mm. These combinations support productive drilling and good hole quality.
For tunnel development, underground power-station works, diversion tunnels, and large mine drifts, hydraulic drill jumbos use development rods in varying lengths with threaded button bits, typically in 45 mm and 48 mm diameters. Coal-mine development operations also increasingly use domestic hydraulic drill jumbos with matching drill rods and six- or seven-button threaded bits.
Surface Drill Jumbo Tools
Surface hydraulic drill jumbos are widely used in hydropower construction, mining, quarrying, excavation, and site preparation. Common tooling includes T38, T45, and T51 threaded MF extension rods, couplings, and threaded button bits in 76 mm, 89 mm, and 102 mm diameters.
Market and Quality Development
Domestic manufacturers produce roughly 300,000 hydraulic drill-jumbo drill rods annually. Development-drilling rods represent about 35% of production, mining extension rods about 15%, and most of the remaining output serves surface drilling. Drill rod exports account for roughly 22% of total production.
China also produces about 2.6 million threaded button bits for hydraulic drill jumbos each year. Development and underground mining bits demand relatively high shell-steel quality, carbide wear resistance, fatigue resistance, and reliable carbide-retention methods. Heat-shrink carbide insertion is widely used for higher-performance products.
Although domestic product quality has improved, further work is needed to improve service life and consistency. Priority areas include hollow-steel quality, thread design and machining accuracy, carburizing and quenching, friction-welding quality, rod straightness, strengthening processes, and corrosion protection.
