Product Description
On a drilling site, the last thing you need is a broken string or a deviated hole. At RockHound, we don’t just “make” rods; we engineer them to survive the punishing reality of medium-to-hard rock. Whether you’re in underground mining or surface quarrying, our T45 Extension Round Rods provide the straightness and durability needed to keep your rigs hitting targets shift after shift.
We use ZK22CrNi3Mo (23CrNiMo) alloy steel for a reason: it’s a high-tier case-hardening steel that handles fatigue where others snap. Combined with precision CNC-machined threads and a full-surface carburization process, these rods feature a “hard-shell, tough-core” structure—perfect for absorbing high-impact energy without sacrificing service life.
From sublevel stoping to bench drilling to tunneling, RockHound T45 rods are engineered to reduce hole deviation, extend thread service life, and maximize energy transmission from rig to bit — cycle after cycle, shift after shift.
Key Features
Premium Steel (23CrNiMo): We don’t cut corners on raw materials. This specific alloy is mill-certified for high impact toughness, drastically reducing the risk of expensive down-hole breakages in abrasive or fractured rock.
Dual-Property Heat Treatment: Through full-surface carburization, we create a wear-resistant skin that protects the rod’s surface while the inner core remains ductile enough to absorb continuous percussive shock.
True-Fit T45 Threads: Our CNC lines hold tight tolerances. This means better metal-to-metal contact, less energy loss, and joints that stay tight under dynamic load.
Precision Straightness: Deep-hole accuracy starts with the rod. We maintain strict dimensional limits to prevent “rod bow,” which not only keeps your holes on target but also saves your guide tubes from premature wear.
Efficient Flushing: The internal channels are optimized for high-volume airflow and water, clearing out cuttings fast and keeping the bit cool to prevent balling in clay-heavy ground.
RockHound T45 (1 3/4″) long-hole drilling string: Shank Adapter → Coupling Sleeve → Extension Rod / MF Rod → Guide Tube → Coupling Sleeve → Ballistic Button Bit / Button Bit / Retrac Bit.
Technical Specifications
| Model | Length (mm) | Length (ft) | Diameter (mm) | Diameter (in) | Thread | Product Code | Weight (kg) |
|---|---|---|---|---|---|---|---|
| T45-Round 46-T45 | 1525 | 5′ | 46 | 1 3/4″ | T45 | 280-4615-7777 | 16.2 |
| T45-Round 46-T45 | 1838 | 6′ | 46 | 1 3/4″ | T45 | 280-4618-7777 | 19.5 |
- Core Material: ZK22CrNi3Mo (23CrNiMo) low-alloy steel
- Finish: Anti-rust coating / Phosphating
- Compatibility: Fully interchangeable with Epiroc (Atlas Copco), Sandvik, and Furukawa T45 systems.
Application
RockHound T45 Extension Round Rods are the field-proven choice for long-hole drilling systems,The RockHound T45 series is the field-proven standard for:
- Underground Mining: Essential for sublevel stoping and long-hole production in metalliferous mines.
- Surface Quarrying: High-throughput bench drilling where rod exchange speed and hole straightness dictate profit.
- Tunneling: Reliable performance in fan drilling and heavy-duty reinforcement bolting.
- Civil Engineering: Long-distance grouting and ground support projects.
Maintenance & Care
1. Don’t Skip the Grease
Always apply high-quality thread grease before every connection. It prevents galling and micro-welding—the two biggest killers of T45 threads.
2. Rotate Your Rods
Don’t let one end take all the abuse. Periodically swap the leading (bit-end) and trailing (rig-end) of the rod. It can boost your total rod life by up to 30%.
3. Stop “Blank Firing”
Hammering without rock contact sends destructive shockwaves straight back into the rod. It’s the fastest way to cause fatigue cracks at the thread roots.
4. Watch the Wear
Use a thread gauge. If the threads look flat or chipped, retire the rod. Running a worn rod will eventually destroy your coupling sleeves and shank adapters too.
How to Choose the Right RockHound Extension Rod
Before specifying RockHound T45 Extension Round Rods for your operation, evaluate the following:
- Drilling Depth & String Configuration For hole depths exceeding 30–40m, integrate a RockHound Guide Tube in the string to maintain hole straightness. For faster rod handling and fewer connection points, consider RockHound MF (Male-Female) Rods as an alternative to the standard coupled rod + sleeve configuration.
- Rock Hardness & Abrasivity RockHound’s ZK22CrNi3Mo (23CrNiMo) specification delivers an optimal balance of surface hardness and core toughness for medium-to-hard rock (UCS 80–200 MPa). For formations with extreme abrasivity (e.g., quartzite, granite >200 MPa), contact RockHound’s technical team to confirm the appropriate heat treatment specification.
- Rig Percussion Energy RockHound 46mm round rods are rated for medium-to-high-power hydraulic drifters. Verify that your rig’s percussion energy and feed pressure fall within the operating range recommended for 46mm rods to prevent bending or fatigue under off-axis loading.
- Thread System Compatibility Confirm T45 thread compatibility across all string components (bit, coupling sleeve, shank adapter). Do not mix T38 and T45 components — RockHound advises that thread geometry mismatch is among the most common causes of rapid joint failure in mixed-inventory operations.
- Length Selection Choose the RockHound 1525mm (5′) rod for tighter headings with restricted breakout clearance, or the 1838mm (6′) rod for standard long-hole production drilling where maximizing advance per cycle is the priority.
Why Choose RockHound
- Mill-Direct Supply Chain: RockHound sources ZK22CrNi3Mo billets directly from qualified steel mills, with full material traceability and heat batch documentation available on request.
- In-Process Ultrasonic Flaw Detection: Every RockHound rod undergoes ultrasonic flaw detection before final machining — zero tolerance for internal defects.
- OEM-Compatible Thread Gauging: All RockHound T45 threads are verified against Atlas Copco / Epiroc and Sandvik gauges to guarantee full interchangeability with your existing equipment.
- Flexible MOQ & Responsive Lead Times: RockHound supports both trial procurement and standing supply agreements, with fast global logistics to active mine sites.
Related Production
The T45 threaded button drill bit is a high-strength drilling tool commonly used for hard rock drilling, and is used in conjunction with T45 threaded coupling sleeve. Its diameter typically ranges from 76mm to 89mm, and common designs include flat-faced and Retrac (retractable) types.The button head can be designed with spherical or parabolic teeth to improve drilling efficiency and wear resistance.
This drill bit is widely used in tunnel excavation, large open-pit mines, and underground copper and gold mines, and is characterized by its fast drilling speed, long service life, and stable performance.
The RockHound T45-46mm Speed MF Rod is purpose-engineered for medium-to-deep-hole extension drilling in demanding underground environments. Unlike conventional extension rods that rely on separate coupling sleeves, the MF (Male/Female) integrated design consolidates the connection point directly into the rod body — reducing energy loss at each joint, improving hole straightness, and dramatically accelerating rod assembly and retrieval on automated drill rigs.
RockHound T45 Coupling Sleeves are precision-machined connectors that form the mechanical backbone of your top hammer drill string. Their core function is to transmit percussive shock energy and rotational torque from the shank adapter through each successive drill rod — with minimum energy loss — to the bit face.
FAQ — RockHound T45 Extension Round Rod
RockHound T45 Extension Round Rods are manufactured from ZK22CrNi3Mo (23CrNiMo), a premium low-alloy case-hardening steel recognized in the rock drilling industry for its high fatigue strength, impact toughness, and resistance to down-hole fracture. All billets are sourced from certified mills with full material traceability.
RockHound currently offers the T45-Round 46-T45 rod in two standard lengths:
- 1525mm (5′) — Product Code: 280-4615-7777 | Weight: 16.2 kg
- 1838mm (6′) — Product Code: 280-4618-7777 | Weight: 19.5 kg
Both variants feature a 46mm (1 3/4″) round body with T45 threads on both ends. Contact RockHound for custom length availability.
Yes. RockHound T45 Extension Round Rods are machined to T45 thread standard and fully compatible with T45-spec equipment from Atlas Copco (Epiroc), Sandvik, Furukawa, and other major hydraulic rock drill manufacturers. All thread profiles are verified against OEM gauges before shipment.
A standard Extension Rod uses identical T45 male threads at both ends and requires a separate Coupling Sleeve to connect rods in a string. An MF (Male-Female) Rod integrates both thread genders into a single piece, eliminating one coupling sleeve per connection. RockHound MF Rods reduce the number of joints in long strings, speeding up rod handling and lowering the risk of coupling sleeve failure in deep-hole applications.
Carburization is a case-hardening heat treatment process in which carbon is diffused into the surface layer of the steel at elevated temperature. RockHound applies full-surface carburization to all T45 Extension Rods, creating a hard, wear-resistant outer case (ideal for thread longevity and abrasion resistance) while maintaining a tough, ductile core (critical for absorbing percussive shock without brittle fracture). This dual-property structure is what differentiates a quality drill rod from a generic one.
The three highest-impact practices are:
- Grease threads before every coupling — prevents galling and thread seizure.
- Rotate the leading end periodically — equalizes wear across both T45 joints.
- Eliminate blank firing — unrestricted percussion without rock contact is the leading cause of premature fatigue fracture in all extension rods, including RockHound products.
Full maintenance guidelines are available in the RockHound T45 Maintenance & Care section above.
For holes deeper than approximately 30–40m, RockHound strongly recommends incorporating a Guide Tube in the drill string. The guide tube stabilizes the leading end of the string, constrains lateral movement, and significantly reduces hole deviation — protecting your RockHound rods, bits, and collars from off-axis stress that accelerates wear and can cause string deflection or stuck rod incidents.
RockHound offers flexible procurement options to suit operations of all scales — from initial trial orders to long-term standing supply agreements. Please contact our sales team with your project specifications (hole depth, rig model, monthly consumption estimate) for a tailored quote and lead time confirmation.