Kenella drifter rods are built for precision in high-impact drilling

In underground drilling, the rod is more than just a connector between the rock drill and the bit. It is a critical load-bearing component that transfers impact energy, rotation, and flushing air or water directly into the rock. Drifter rods, also known as drifter drill rods, club rods, or drifting rods, are designed specifically for top hammer percussive drilling systems used in tunnelling, drifting, underground mining, and rock bolting.

Kenella Drifter Rods

Understanding the Design and Functionality of Drifter Rods

A drifter rod is typically a single-piece, hollow steel rod manufactured from high-strength alloy steel and heat-treated to withstand severe shock loading. In operation, it must handle repeated impact from hydraulic or pneumatic drifters, while also resisting vibration, torsion, bending, and misalignment in fractured or abrasive ground conditions.

Most drifter rods are produced with a hexagonal cross-section, which improves torque transmission and rigidity. Round rods are also available, depending on the application and rig requirements. One end connects to the shank adapter, either directly or through a coupling sleeve, while the opposite end threads directly into the drill bit.

Common thread types include: R25, R28, R32, T38, T45, and T51. The R-series is typically used for smaller diameter and shorter-hole applications, while the T-series is suited to heavier-duty drilling. Drifter rods are generally shorter than extension rods, often ranging from around 1.5 m to 4.3 m, making them ideal for short to medium holes where accuracy, stability, and durability are essential.

Durability and Flexibility: Key Attributes of Drill Rods in Harsh Environments

These rods work in some of the harshest drilling environments. They need the stiffness to resist bending in hard rock, but enough flexibility to survive constant vibration and occasional alignment issues. Poor metallurgy or incorrect heat treatment can lead to fatigue, twisting, or sudden failure — causing costly downtime underground.

Kenella Range: Reliable Drifter and Tunnelling Rods by Harlen Supplies

Harlen Supplies offers their Kenella range of drifter and tunnelling rods, including R25, R28, and R32 options for underground and surface mining applications. Available in hex and round profiles, the range is engineered for reliable performance, strong compatibility, and a competitive price-to-performance ratio against established industry favourites.