What Is a Self Drilling Anchor Bolt?
A Self Drilling Anchor Bolt is a hollow threaded steel bar that serves as both a drill rod and an anchor rod. During drilling, grout flows through the hollow core, bonding the anchor directly with the surrounding formation.
The system is widely used together with drilling equipment such as crawler drilling rigs and air compressors
Components of the Self Drilling Anchor System
A complete SDA system consists of:
Hollow Anchor Bar
Available in T30 / T40 / T45 / T52 / T73 / T76.
Drill Bits
Different ground conditions require different bits:
Carbide bits
Clay bits
Cross bits
Wing bits
Couplers & Nuts
Used for bar extension and tensioning.
Bearing Plates
Provides support at the surface.
Grout Injection Accessories
Key Features of Dminingwell Self Drilling Anchor Bolt
① One-Step Construction – No Casing Required
This feature makes it especially suitable for soft or loose ground that collapses easily.
② High Load Capacity
Continuous external threads provide excellent tensile strength, meeting the requirements of foundation reinforcement and rock support.
③ Hollow Core for Grouting
Ensures complete filling and strong bonding.
④ Wide Range of Drill Bits
Suitable for sand, gravel, weathered rock, fractured rock, and mixed formations.
⑤ Optional Anti-Corrosion Protection
Hot dip galvanizing
Epoxy coating
Dual corrosion protection
Technical Parameters (Example Models)
1. Hollow Anchor Bar
| Image | Model | Tensile Strength (kN) | Yield Strength (kN) | Elongation (%) | Notes |
|---|---|---|---|---|---|
| (image) | HER25N | 200 | 150 | 8 | Left-hand or right-hand thread can be customized |
2. Drill Bits
| Image | Type | Model | Diameter (mm) | Suitable Ground Conditions |
|---|---|---|---|---|
| (image) | Cross Steel Bit | HSR25/42 | 42 | Mudstone, gravel soil, chalk, limestone, clay soil, artificial fill, weak concrete |
| (image) | Cross Carbide Bit | HSR25/42 | 42 | Soft–medium rock, gravel with cobbles, fractured rock, unreinforced concrete |
| (image) | Button Steel Bit | HSR25/42 | 42 | Broken formations, soft sandstone, limestone, gravel, soft rock layers |
| (image) | Button Carbide Bit | HSR25/42 | 42 | Soft–medium weathered rock, cobblestone layers, tuff, phyllite, volcanic rock |
3. Nuts
| Image | Type | Model | Across Flats (mm) | Length (mm) | Notes |
|---|---|---|---|---|---|
| (image) | Hex Nut | HER25-L35 | 41 | 35 | Strength-matched with the compatible anchor bar |
| (image) | Spherical Nut | HER25-L40.5 | 41 | 40.5 | Strength-matched with the compatible anchor bar |
4. Anchor Plate
| Image | Type | Model | Side Length (mm) | Thickness (mm) | Notes |
|---|---|---|---|---|---|
| (image) | Square Plate | HER25-L150-T6 | 150 | 6 | Custom sizes available |
5. Drill Bit Adapter
| Image | Model | Compatible Anchor Bar | Compatible Bit | Notes |
|---|---|---|---|---|
| (image) | SSR25/R32 | R25 | R32 | Enables connection between R25 anchor bars and larger R32 drill bits |
6. Other Accessories
| Image | Accessory Name |
|---|---|
| (image) | Guide Sleeve |
| (image) | Rotary Grouting Adapter |
| (image) | Shank Adapter for Pneumatic Rock Drill |
| (image) | Shank Adapter for Hydraulic Rock Drill |
| (image) | Shank Adapter for DTH Hammer |
Applications of Self Drilling Anchor Bolt
-
The system is widely used in:
✔ Tunneling & Underground Construction
For rock support, vault reinforcement, and pre-grouting.
【： Tunnel Drilling Rig】✔ Mining & Caverns
Roof bolts, sidewall reinforcement.
✔ Slope Stabilization & Landslide Prevention
Works effectively in loose soil and fractured slopes.
【 ：Geotechnical Drilling Rig】✔ Foundation Reinforcement & Micropiles
Self Drilling Anchor Bolts often work alongside:
【 ：Rotary Drilling Rig】
【 ：Hydraulic Crawler Rig】
Comparison: SDA Bolt vs Traditional Anchor
| Traditional Method | SDA Bolt |
|---|---|
| Needs casing | No casing required |
| Borehole collapses easily | Stable drilling even in loose soil |
| Slow construction | High installation speed |
| Multi-step process | One-step drilling + grouting + anchoring |
How SDA Bolts Work With Your Other Products
To improve drilling efficiency, an SDA system is often paired with:
✔ Screw Air Compressor
Provides continuous high-pressure airflow for drilling.
【 ：Mobile Screw Air Compressor】
✔ DTH Hammer & DTH Bit
When drilling into harder geological formations.
【 ：DTH Hammer Series】
✔ Water Well Drilling Rig / Crawler Drilling Rig
Used for ground preparation and pre-support drilling.
【 ：Water Well Drilling Rig】
【 ：Crawler Pneumatic Drilling Rig】
Why Choose Dminingwell Self Drilling Anchor Bolt?
High-strength steel anchor bars
Full range from T30–T76
CE/ISO-certified production
Custom lengths, drill bits, coatings, and accessories
Large inventory & fast delivery
Strong engineering support and long-term project experience
与企业品牌类内链自然结合：
【 ：About Dminingwell】
FAQ
Q1: Can Self Drilling Anchor Bolts be used in sandy or collapsing formations?
Yes. SDA bolts are designed for weak, loose, and collapsing ground where traditional anchors fail.
Q2: Can I choose my own drill bit type?
Of course. We offer clay bits, cross bits, carbide bits, and wing bits depending on the rock condition.
Q3: Do you provide full SDA systems?
Yes. Hollow bars, couplers, nuts, plates, bits, and grouting accessories are all available.
Q4: Is anti-corrosion coating available?
Yes, hot-dip galvanizing or epoxy coating can be added for long-term projects.
Q5: Can SDA bolts work with your drilling rigs?
Yes. SDA bolts are fully compatible with Dminingwell drilling machines：
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