Product Description
RockHound T38-H35-T38 MF Drill Rod is specifically engineered for medium to heavy-duty drifting and tunneling applications. By integrating the coupling sleeve directly into the rod as a female end, this MF(Male-Female) design ensures tighter connections, higher energy transmission efficiency, and reduced thread wear.
Crafted from premium ZK22CrNiMo high-strength alloy steel, our rods are designed to withstand the extreme impact energy of modern hydraulic drifters, significantly reducing the risk of rod breakage and downtime.
Key Features
Premium Material: Manufactured from ZK22CrNiMo alloy steel, providing superior fatigue strength and excellent wear resistance.
MF Design: The Male-Female thread design eliminates the need for separate coupling sleeves, ensuring straighter holes and faster rod changes.
Advanced Heat Treatment: Full-body carburization and surface hardening treatments maximize the service life of the T38 threads.
Optimized Flushing: Large flushing holes ensure efficient cuttings removal, preventing regrinding and increasing drilling speed.
Hexagonal Stability: The H35 hex section provides better rigidity and reduces bending during high-torque operations compared to round rods.
Technical Specifications
| Product Code | Rod Section | Thread (Both Ends) | Length (mm) | Length (ft/in) | Weight (kg) |
|---|---|---|---|---|---|
| 296-3537-7654 | H35 Hex | T38 – T38 | 3700 | 12′ 1 1/2″ | 29.4 |
| 296-3543-7654 | H35 Hex | T38 – T38 | 4305 | 14′ 3/64″ | 34.4 |
| 296-3549-7654 | H35 Hex | T38 – T38 | 4915 | 16′ 1 1/2″ | 38.9 |
| 296-3555-7654 | H35 Hex | T38 – T38 | 5525 | 18′ 33/64″ | 43.8 |
Note: Custom lengths and specific thread configurations (like the R32 end shown in some diagrams) are available upon OEM & ODM request.
Applications
This T38 MF rod is the industry standard for:
- Tunneling: High-speed development in civil engineering.
- Drifting: Precision horizontal drilling in underground mining.
- Bench Drilling: Small to medium-sized benching operations.
- Bolting: Deep hole reinforcement in unstable rock formations.
Maintenance Tips
To maximize the ROI of your ZK22CrNiMo drill rods, follow these maintenance steps:
Thread Lubrication: Always apply high-quality thread grease before coupling to prevent galling and heat buildup.
Visual Inspection: Regularly check for cracks, nicks, or excessive thread wear. Replace rods if threads become “sharp.”
Straightness Check: Avoid using bent rods, as they increase vibration and accelerate wear on the drifter’s shank adapter.
Proper Storage: Store rods in a dry environment and avoid direct metal-to-metal impact during transport.
Field Test Report:T38-H35 MF Rods
Specification: 23CrNi3Mo H35×4305-T38/R32 (Hex 35mm, Length 4305mm)
Quantity: 8 Pieces
| Serial No. | Service Life / Footage (m) | Failure Mode |
|---|---|---|
| 1# | 3529 | Breakage at Small End Thread (Bit End) |
| 2# | 3753 | Breakage at Small End Thread (Bit End) |
| 3# | 3478 | Breakage at Small End Thread (Bit End) |
| 4# | 3389 | Breakage at Small End Thread (Bit End) |
| 5# | 3645 | Breakage at Small End Thread (Bit End) |
| 6# | 3725 | Breakage at Small End Thread (Bit End) |
| 7# | 3712 | Breakage at Small End Thread (Bit End) |
| 8# | 3549 | Breakage at Small End Thread (Bit End) |
| Average | 3597.5 m | Breakage at Small End Thread (Bit End) – 100% of samples |
How to Choose the Right MF Drill Rod?
Choosing the correct rod depends on three factors:
Rock Hardness: For hard, abrasive rock, the ZK22CrNiMo material of our T38 rods offers the best fatigue resistance.
Drill Rig Power: T38 threads are ideal for medium-sized hydraulic rock drills (18kW – 25kW).
Hole Depth: MF rods are preferred for deeper drifting as they provide better alignment and easier uncoupling than traditional rod-and-coupling systems.
Related Production
FAQ
The MF design integrates the coupling sleeve directly into the female end of the rod. This offers three major benefits:
Higher Energy Transfer: Fewer joints mean less energy loss from the drifter to the bit.
Straighter Holes: The integrated connection is more rigid, reducing hole deviation in long-hole drifting.
Increased Efficiency: Eliminates the need for separate coupling sleeves, making rod handling faster and reducing the risk of lost or stuck couplings.
ZK22CrNiMo is a high-grade chromium-nickel-molybdenum alloy steel specifically developed for high-impact rock drilling.
It offers an exceptional balance of core toughness and surface hardness.
Compared to standard carbon steel, it provides significantly higher fatigue strength, ensuring the T38 threads can withstand millions of high-frequency impacts without premature fracturing.
RockHound T38-H35 MF rods are designed to industry-standard specifications and are fully compatible with top-tier hydraulic drifters, including models from:
Epiroc (Atlas Copco): COP series.
Sandvik: HL series.
Montabert & Furukawa: Various medium-to-heavy drifter models.
Any drifter equipped with a T38 shank adapter.
The H35 Hexagonal section is the preferred choice for drifting and tunneling because:
Higher Rigidity: It resists bending better than round rods of similar weight.
Better Flushing: The hex shape allows for more clearance between the rod and the hole wall, improving the removal of rock cuttings (flushing) and preventing the rod from getting stuck.
To maximize thread life:
Always use thread grease: Apply a lead-free or copper-based lubricant to every joint.
Proper Torque: Ensure the drifter's feed pressure and rotation torque are balanced to prevent excessive heat buildup.
Replace Worn Bits: Never use a dull drill bit, as it sends excessive vibration back through the threads of the MF rod.
RockHound standard stock includes lengths ranging from 3700mm (12') to 5525mm (18'). These lengths are optimized for standard tunneling jumbo feed beams. We also offer custom lengths upon request to match your specific drifting requirements.


