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R38 Self Drilling Hollow Anchor Bar System
R38 Self Drilling Anchor Bar for Foundation Pit Support
R38 Self Drilling Hollow Anchor Bar for Metro Tunnel
R38 Self Drilling Hollow Anchor Bar System
R38 Self Drilling Anchor Bar for Foundation Pit Support
R38 Self Drilling Hollow Anchor Bar for Metro Tunnel

R38 Self-Drilling Hollow Anchor Bar | Hollow Grouting Anchor Bolt for Tunnel and Mining Support

R38 self-drilling hollow anchor bar is a kind of high strength hollow type threaded anchor used for tunnel support, mine reinforcement, slope control and geo-technical construction etc. Hollow anchor bar combines drilling, grouting and anchoring operation into one step drilling. It is applied in fractured rock, loose rock mass, soft layer and underground engineering.

R38 hollow anchor bar adopts 38 mm outer diameter thread design and it is divided into R38N/21 and R38N/19 two kinds of type. Due to its hollow middle, it can be used as grouting channel, fill the hole by grouting, cemented with the surrounding rock to enhance the support effect.
  • Self-drilling anchor bar with hollow center section for fast, efficient installation.
  • Used with pressure grouting through hollow center.
  • Applied in tunneling, mining and geotechnical projects.
  • High ultimate load value and yield load capacity.
  • Threaded profile creates better bond with grout and ground.
  • Controls ground deformation; stabilizes rock mass.
  • Available with various nuts, couplers, plates, centralizers and drill bit adapter.
  • Offer left-hand thread or right-hand thread option.
  • Optional corrosion protection available.
  • Suitable for temporary support and permanent reinforcement applications.
Product Description

1.Technical Specifications

 

Item R38N/21 R38N/19
Outer Diameter mm 38 38
Inner Diameter mm 22 19
Cross Section Area mm2 611 700
Ultimate Load kN 500 500
Yield Load kN 400 400
Weight kg/m 4.8 5.5
Thread Type ISO10208 ISO10208
Steel Grade EN10083-1 EN10083-1
Thread Direction Left or right Left or right
Length m 1, 2, 3, 4, 5, 6, 7, 8, 9 1, 2, 3, 4, 5, 6, 7, 8, 9
Corrosion Protection Optional Optional

 

 

2. Accessories

 

Accessory Main Specification
Nut Size 50 mm, length 60 mm, hardness HRC 25-30, steel CK45, ISO10208 thread, weight 0.25 kg
Coupler Outer diameter 52 mm, length 40 mm, hardness HRC 23-30, steel EN10083-1, ISO10208 thread, weight 1.8 kg
Bearing Plate 200 x 200 mm, thickness 12 mm, hole diameter 41 mm, weight 3.6 kg
Centralizer Outer diameter 72 mm, length 41 mm, hole diameter 50 mm, steel CK45, weight 0.3 kg
Drill Bit Adapter Anchor thread R38, drill bit thread R51 / T52 / T73 / T76, length 50 mm, weight 0.1 kg

 

 

3. Applications

Common uses include:

  • Tunnel support
  • Coal mine roadways
  • Rock bolt support
  • Slope reinforcement
  • Foundation anchorage
  • Metro tunnels and railway tunnels
  • Hydropower projects
  • Underground caverns
  • Broken rock reinforcement
  • Temporary ground support and permanent ground support.

 

4. Advantages

The self-drilling anchor system eliminates this problem.

 

 

5. Corrosion Protection Options

Options include:

* Hot-dip galvanized per ISO 14 61

* Impact tested per ASTM D27 94
* Adhesion tested to ISO 24 09:2007

 

 

6. Custom Options


Custom Options Include
√ Anchor bar length
√ Threaded surface:left/right
√ Nut
√ Coupler length
√ Bearing plate size
√ Drill bit adapter
√ Corrosion protection options
√ Packaging method

 

 

7. FAQ




A: Yes! 


Q: Does rust preventions options are available?
A: Yes. 

Hollow anchor rod 1
Hollow anchor rod 2
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End-to-End Ground Support Solutions

We deliver complete support for underground reinforcement applications, covering: Mining roof and sidewall support systems Tunnel reinforcement solutions Slope stabilization engineering support Foundation anchoring systems Underground safety structural systems From early-stage project planning to on-site application, we help customers build safer and more stable underground environments.

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Product Supply & System Integration

Wanfeng provides a fully integrated product supply system, enabling customers to source all ground support materials from one supplier: Rock bolt systems (resin / FRP / threaded) Cable bolts & anchoring systems Steel arches & I-steel support systems Wire mesh & reinforcement mesh Plates, nuts, bolts & fastening components Resin & cement anchoring materials Mining tools & consumable accessories Our one-stop supply capability reduces procurement complexity and improves project efficiency.

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Manufacturing & Quality Assurance Services

We ensure stable and reliable product performance through strict manufacturing and quality control systems: Standardized production processes Raw material inspection and control Mechanical performance testing Load-bearing and tensile strength verification Batch consistency inspection Final quality inspection before shipment Every product is engineered to meet demanding underground safety requirements.

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Custom Engineering & OEM Services

We also support customized solutions for different mining and engineering projects: Customized rock bolt specifications Non-standard steel support design Special mesh and reinforcement structures Project-based product configuration OEM / private label cooperation We work closely with global partners to develop tailored solutions for complex underground environments.

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Global Supply & Logistics Support

With strong export experience, we provide efficient global delivery and supply chain support: International export packaging standards Container loading optimization Multi-region shipping support Fast production scheduling for urgent projects Stable long-term supply agreements We ensure reliable delivery to mining projects across different countries and regions.

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We support customers throughout the entire project lifecycle: Technical documentation support Installation guidance assistance Product replacement support Long-term supply continuity Engineering consultation for project expansion Our goal is to build long-term partnerships, not just single transactions.

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