T51 Coupling Sleeve: High-Torque Connector for Top-Hammer Rock Drilling
T51 coupling sleeves are core connecting components in top-hammer rock drilling tools, used to connect T51 specification drill rods and shanks. They are engineered for heavy-duty operations including open-pit mining and tunnel excavation, delivering high torque transmission, exceptional durability, and precise power transfer.
Mainstream Types and Applications
Semi-Bridge Type
- Structure: Features a non-threaded isolation bridge in the middle that prevents drill pipe threads from passing through
- Advantages: High torque resistance, prevents thread slippage, ideal for heavy-duty drilling rigs
- Applications: High-torque downhole operations, deep hole drilling, and frequent impact conditions
Full-Bridge Type
- Structure: Continuous threading without isolation bridge, eliminating connection creep risk
- Advantages: Easy disassembly, strong joint sealing, low drill pipe jamming rate
- Applications: Open-pit mining, quarries, and large-diameter shallow hole operations
Crossover Type
- Structure: Different threads at both ends (e.g., T45-T51) for connecting various drilling tool specifications
- Advantages: Compatible with multiple drill pipe and bit models, reduces equipment adaptation costs
- Applications: Mixed specification drilling tool usage, equipment upgrade and modification projects
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Coupling sleeves
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Length
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Outer dia.
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Thread
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Weight (kg)
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HengLongDRLL P/N
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mm
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foot
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mm
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inch
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|

|
225
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8 7/8
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71
|
2 51/64
|
T51
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4.6
|
31-T51-71-225-23
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|
225
|
8 7/8
|
76
|
3
|
T51
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4.8
|
31-T51-76-225-23
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|
235
|
9 1/4
|
72
|
2 7/8
|
T51
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4.7
|
31-T51-72-235-23
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|
235
|
9 1/4
|
77
|
3 1/32
|
T51
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4.9
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31-T51-77-235-23
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Technical Features and Performance Benefits
- High Torque and Fatigue Resistance: Carburizing and quenching process enhances surface hardness and core toughness, withstanding high-frequency impacts and rotational torque for extended service life
- Precise Power Transmission: Semi-bridge type uses isolation bridge positioning while full-bridge type features continuous threading, ensuring efficient power transfer and reducing thread loosening risks
- Superior Compatibility: Works with mainstream top hammer drilling rigs (Atlas Copco, Sandvik) and supports custom lengths, surface treatments, and diameter specifications
- Reduced Maintenance: Full-bridge type offers easy disassembly while semi-bridge type provides excellent anti-fouling capabilities, lowering on-site maintenance costs