Mining Rock Bolts Self Drilling Anchor System Drilling Tools For Reinforcement
Mining Rock Bolts Self Drilling Anchor System Drilling Tools For Reinforcement
The self-drilling hollow bar anchor system consists of a hollow threaded bar with an attached drill bit that can perform drilling, anchoring and grouting in a single operation. The hollow bar allows air and water to freely pass through the bar during drilling to remove debris and then allow grout to be injected immediately after drilling is completed. Grout fills the hollow bar and completely covers the entire bolt. Couplings can be used to join hollow bars and extend the bolt length while nuts and plates are used to provide the required tension.
Self-drilling hollow bar anchor system is the most common used system for rock mass stabilization, especially in tunneling, underground mining and ground engineering industry. It is mainly used for the supporting engineering in the loose and broken rock stratal with difficult to drilling hole. It provides the optimal solution for soil nailing, lock bolting, micro-piling.
Self-drilling hollow bar anchor system fulfills current and increasing demands of the tunneling, mining industry and ground engineering for safer and faster production. The system provides advantages for all areas of its applications, where boreholes would require the time consuming drilling with casing systems in unconsolidated or cohesive soil.
Features and Advantages
- Particularly suitable for difficult ground conditions.
- An efficient installation since drilling, placing and grouting can be performed in a single operation, saving both time and money.
- Self-drilling system eliminates the requirement for a cased borehole in collapsing soils.
- Fast, single-step anchoring system with simple equipment able to work with standard track drill (top hammer) or hand-held drilling equipment, eliminating the need for larger casing rigs.
- Installation with simultaneous drilling and grouting possible, and post grouting system is simple.
- Continuously drilling and grouting under high pressure causes the grout to permeate into looser soils and creates a bulb-effect for increased bond capacity.
- Easy installation in all directions, also upwards, and similar installation methods for all ground conditions.
- Suitable for working in limited space, height and in areas of difficult access.
- Galvanizing for enhanced corrosion protection is available if necessary.
- Multiple ranges of drill bits suitable for different ground conditions.
- Continuously threaded bar pattern can be cut and coupled anywhere along its length to achieve all lengths.
Specification
Anchor bolt
| Item | R25N | R32N | R32S | R38N | R51L | R51N | T76N | T76S |
| Outside Diameter (mm) | 25 | 32 | 32 | 38 | 51 | 51 | 76 | 76 |
| Internal Diameter (mm) | 14 | 19 | 16 | 19 | 36 | 33 | 52 | 45 |
| Ultimate Load Capacity (kN) | 200 | 280 | 360 | 500 | 550 | 800 | 1600 | 1900 |
| Yield Load Capacity (kN) | 150 | 230 | 280 | 400 | 450 | 630 | 1200 | 1500 |
| Tensile Strength, Rm (N/mm2) | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 |
| Yield Strength, Rp0.2 (N/mm2) | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 |
| Weight (Kg/m) | 2.3 | 3.2 | 3.6 | 5.5 | 6.5 | 8.0 | 16.0 | 19.7 |
| Thread Type (left-hand) | ISO10208 | ISO1720 | MAI T76 Standard | |||||
| Steel Grade | EN10083-1 (Alloy Structure Steel) | |||||||
| Compared to carbon steel, alloy structure steel has high anti-corrosion capacity and high mechanical. | ||||||||
Anchor Plate
| Item | R25N | R32N | R32S | R38N | R51L | R51N | T76N | T76S |
| Dimention(mm) | 150*150 | 200*200 | 200*200 | 200*200 | 200*200 | 250*250 | 250*250 | 250*250 |
| Thickness(mm) | 8 | 10 | 12 | 12 | 20 | 40 | 40 | 40 |
| Hole diameter(mm) | 30 | 35 | 35 | 41 | 60 | 60 | 80 | 80 |
| Weight(KG/PC) | 1.4 | 3 | 3.7 | 3.6 | 8.8 | 18.5 | 18 | 18 |
| Cold deformed with geometry | ||||||||
Anchor Coupling
| Item | R25N | R32N | R32S | R38N | R51L | R51N | T76N | T76S |
| Outside diameter(mm) | 35 | 42 | 42 | 52 | 63 | 63 | 95 | 95 |
| Length(mm) | 120 | 145 | 160or190 | 180 | 180 | 200 | 200 | 200 |
| Weight | 0.45 | 0.7 | 0.75 | 1.4 | 1.7 | 1.9 | 6.4 | 6.4 |
| Machined steel coupling middle stop | ||||||||
Drill Bit
| Item | R25N | R32N | R32S | R38N | R51L | R51N | T76N | T76S |
| diameter(mm) | 41,51 | 51,76,90 | 90,100,110,115,130 | 130,150,160,180,200 | ||||
|
Hardened cross bit (EX) |
Hardened cross bit for loose to medium dense condition with small boulders. | |||||||
|
Tungsten cross bit (EXX) |
TC cross bit for soft to medium rock for mations | |||||||
|
Hardened button bit (ES) |
Hardened buuton bit for unconsolidated rock with boulders. | |||||||
|
Tungsten carbon button bit (ESS) |
Button bit with TC inserts for medium rock for formations. | |||||||
|
Hardened arch bit (EC) |
Hardened drill bit with optimized geometry for unconsoliddated soil with small boulders. |
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|
Tungsten carbon arch bit (ECC) |
TC drill bit with optimized geometry for soft to medium rock formations. | |||||||
|
Hardened drop center bit (EY) |
Hardened cross bit for loose to medium dense ground conditions | |||||||
|
TC drop center bit (EY) |
TC drill bit for soft to medium rock formations. | |||||||
|
Casting clay bit (EW) |
Casting clay bit with optimized geometry for very soft to soft caly. | |||||||
| Machined steel bit or Casring steel bit | ||||||||
Anchor Nut
| R25N | R32N | R32S | R38N | R51L | R51N | T76N | T76S | |
| Key size(mm) | 41 | 46 | 46 | 50 | 75 | 75 | 100 | 100 |
| Length(mm) | 135 | 45 | 45 | 55 | 70 | 70 | 80 | 80 |
| Weight(kg/pc) | 0.25 | 0.35 | 0.35 | 0.5 | 1.55 | 1.55 | 3.6 | 3.6 |
| Machined steel nut or casting steel nut | ||||||||
About us
MIROC® Rock Drilling Tools are Rock Drilling Tools Brand by KSQ Tecnologies (Beijing) Co. Ltd.
KSQ Technologies (Beijing) Co. Ltd. provides exceptional technical know-how in development, production, and application. The company has adopted advanced manufacturing processes to ensure high quality steels and tungsten carbide inserts for its rock drilling accessories. Its personnel understand clients’ drilling needs, and have the service skills to recommend the right drilling tools for the job. Its experienced product developers can also create custom tools. Furthermore, the company’s development team introduces innovative products each year – tools that are rigorously tested in the field and proven
to perform beyond industry expectations.
MIROC® Rock Drilling and Ground Support Tools include:
Integral Rods
Plug Hole Rods
Tapered Drilling Tools
Extension Drilling Tools
Drifting and Tunneling Tools
Reaming Tools
Shank Rods
Shank Adapters (Striking Bars)
Down-the-hole (DTH) Bits
Down-the-hole (DTH) Hammers
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.

