Heavy duty wireline drill rods are specifically designed for deep hole drilling operations reaching up to 3,000 metres. In such demanding environments, standard rods often reach their mechanical limits. Therefore, reinforced solutions become essential for safety, performance, and drilling efficiency.

A deep hole wireline drill rod must withstand extreme torque, high tensile loads, and continuous mechanical stress. Consequently, manufacturers focus on metallurgy, thread design, and structural stability to guarantee reliable core recovery at great depths. According to the Technidrill catalogue, heavy duty wireline rods are engineered precisely for these critical conditions .

Purpose and applications of heavy duty wireline rods

Heavy duty wireline rods are mainly used in deep exploration drilling, including mineral exploration, geothermal projects, and large-scale geotechnical investigations. Because drilling depth increases friction and load, rod failure risks rise sharply.

As a result, these rods are recommended when:

• Drilling exceeds standard depth limitations
• High torque transmission is required
• Borehole deviation must be minimised
• Long rod strings are permanently under tension

Moreover, a deep hole wireline drill rod ensures continuous coring without frequent rod handling. This improves productivity while also enhancing operator safety.

Advanced manufacturing for extreme depths

Cold-drawn seamless steel tubes

The main rod body is produced from cold-drawn seamless steel tubing. This manufacturing process improves dimensional accuracy and internal surface quality. As a result, straightness and hoop stress are tightly controlled throughout the rod length.

Because no longitudinal weld is present, structural weaknesses are eliminated. Therefore, the rod maintains consistent mechanical behaviour even under cyclic loading.

Friction-welded high-strength tool joints

The rod ends are friction welded to specially treated alloy steel tool joints. This process creates a homogeneous metallurgical bond without filler material. Consequently, mechanical resistance is significantly higher than with conventional welding.

In addition:

• Tool joints feature increased wall thickness
• Stress concentration zones are reduced
• Fatigue resistance is improved

These characteristics are essential for deep hole wireline drill rod assemblies, where joint failure is not an option.

Thread design optimised for deep hole drilling

Thread geometry plays a crucial role in deep drilling. Therefore, heavy duty wireline rods use specific thread profiles developed for high torque and tensile resistance.

Key advantages include:

• Improved load distribution along the threads
• Reduced risk of thread deformation
• Stable make-up and break-out operations

Furthermore, surface treatment on the male threads prevents galling. This treatment extends service life and ensures consistent performance over repeated drilling cycles.

Dimensional options: 70 HD and 94 HD deep hole wireline rods

70 HD Heavy Duty Wireline Drill Rods

70 HD rods are designed for deep drilling while maintaining manageable weight. They are commonly selected for medium-diameter deep hole projects.

Typical characteristics include:

• Outer diameter around 69.9 mm
• Inner diameter of approximately 55 mm
• Available lengths in 3 m, 6 m, 10 ft, and 20 ft

Because of their balance between strength and handling, 70 HD rods are frequently used in deep mineral exploration programs .

94 HD Heavy duty deep hole wireline drill rods

94 HD rods are intended for maximum strength and stiffness. They are preferred when drilling conditions are extremely demanding.

Their main features include:

• Larger outer diameter of 94 mm
• Increased internal diameter for improved flushing
• Higher individual rod weight, enhancing stability

As a deep hole wireline drill rod solution, 94 HD models deliver superior resistance to torsion and elongation in very deep boreholes.

Packaging and logistics efficiency

Heavy duty wireline rods are supplied in optimised bundles to ensure safe transport and easy handling. Bundle dimensions and weights are calculated to maximise container capacity while maintaining safe lifting conditions.

For example:

• 70 HD rods are packed in bundles of 19 units
• 94 HD rods are packed in bundles of 10 units
• Full 20-foot containers can be efficiently loaded without wasted space

This logistical optimisation reduces transport costs and simplifies site operations, especially for remote drilling projects .

Why choose a deep hole wireline drill rod solution?

Choosing the right deep hole wireline drill rod directly impacts drilling performance and project profitability. Heavy duty rods reduce downtime, minimise tool failures, and improve core recovery quality.

In summary, they offer:

• Superior mechanical resistance
• Long service life under extreme conditions
• Consistent performance at depths up to 3,000 metres

Therefore, heavy duty wireline rods are not just a component, but a strategic investment for deep drilling success.

Heavy duty wireline drill rods are engineered to meet the toughest deep drilling challenges. Through advanced steel selection, friction-welded tool joints, and specialised thread designs, they provide unmatched reliability at extreme depths. If you’re looking for standard wireline rods, let’s check the whole wireline range here: https://technidrill.com/en/mining-exploration/#CABLE.