Sandvik Tapered Drill Rod Series: Specifications, Performance, and Selection Guide
Sandvik Tapered Drill Rod Series
Sandvik tapered drill rods are core drilling tools for top-hammer applications in mining, tunnel excavation, quarrying, and related rock-drilling projects. The series covers a wide range of specifications and can be matched with compatible Sandvik tapered bits for different geological and equipment conditions.
Product Structure and Equipment Compatibility
The rods use an integrated forged shank structure that provides stable and uniform load transfer with strong resistance to impact loads.
The rod body is available in two widely used hexagonal cross-sections: Hex 22 and Hex 25. These configurations can be matched with different low-pressure and high-pressure rock drills, supporting equipment installation, power transmission, and drilling operations across multiple job sites.
Taper Angles and Length Range
The product series includes common connection tapers of 4.46°, 7°, 11°, and 12°. Rod lengths range from 0.4 m to 9.6 m.
Short rods can be used for conventional shallow-hole drilling within 2 m, while longer rods are suitable for deep-hole and long-distance development work. The range can be adapted to soft rock, medium-hard rock, hard rock, and other complex geological conditions.
Selection should consider the matching bit taper, drilling depth, rock-drill model, pressure level, and actual rock conditions.
Carburizing Heat Treatment
Sandvik tapered drill rods use a mature carburizing heat-treatment process. The resulting structure provides adequate overall rigidity, relatively high surface hardness, lower core hardness, good wear resistance, and balanced toughness.
This surface-hard and core-tough structure improves load-bearing performance and drilling stability under repeated impact, rotational torque, and difficult rock conditions.
Shot Peening and Fatigue Resistance
All rods undergo shot-peening treatment. The process helps relieve residual stress, reduce cracking and deformation, and create beneficial compressive stress on the surface.
Improved surface stress conditions increase fatigue resistance and slow structural wear caused by long-term high-frequency impact drilling. This can extend the rod’s circulation life and reduce downtime caused by frequent consumable replacement.
Forged Shank Design and Corrosion Protection
The shank is a critical load-bearing area. The series uses a full forged-boss design with high coaxiality on both sides of the shank. Compared with some commonly used tapered rod shank designs, this structure improves impact and torsional resistance and helps distribute operating loads more evenly.
The rods also receive SR corrosion-protection treatment for outdoor, underground, humid, and dusty environments. They are manufactured from specialized low-carbon, high-nickel steel with high material purity and suitable toughness.
Straightening and Drilling Accuracy
Before shipment, every rod is manually checked for straightness after individual straightening. Strict control of rod straightness helps improve borehole alignment, drilling accuracy, and overall operating stability.
Better straightness can also reduce the total drilling cost per meter by lowering deviation, rework, and premature tool replacement.
Advantages and Selection Limits
Carburized Sandvik tapered drill rods offer strong impact resistance, torsional resistance, wear resistance, fatigue performance, and environmental adaptability. Their advantages are more apparent in hard rock and when used with high-power rock drills.
However, the rods have certain selection limits. They place relatively high requirements on the quality of the rock-drill shank bushing. Compared with commonly used tapered rods in China and Epiroc tapered rods, their purchase price and cost-effectiveness may be less attractive in some applications.
Under ordinary rock conditions or with low-power rock drills, the performance advantage may not be as noticeable. Buyers should therefore compare rock hardness, drill power, shank-bushing condition, hole depth, required service life, and total consumable cost instead of selecting solely by brand or individual performance index.
