Steel Drilling Anchor System
Hollow Bar Anchor System
Introduction:
The core of the Onton Self-Drilling Anchor Bolt is a hollow, thick-walled, central drilling rod with a drill bit at the top. The system is modular, meaning that the most appropriate configuration can be put together to suit on-site circumstances and the forces that apply.
T Thread Self-Drilling Anchor
The self-drilling anchor bolts are available in the steel grade S460NH and other common types. All of steel materials are produced according to EN 10210-1 "Hot finished structural hollow sections of non-alloy and none grain steels" and have excellent capacity to the short time simultaneously dynamic loads (torque, frequent percussion impact, bending moments) during drilling as long-term load and durability.
Good Ductility ensures No Sudden Fracture while drilling
Working Process:
The system is used to create anchors in soft or unstable ground. Drilling, positioning of the reinforcement and injection are carried out in a single operation, thereby avoiding the difficult task of drilling a casing hole.
A disposable drill bit is screwed onto the first rod. The steel hollow bar is then connected directly to the drill rig (if necessary using an injection swivel).
Drilling starts with simultaneous injection via the central hole in the bar. As the drill bit features a hole, the cement grout spreads into the ground as the drill moves forward.
When the first bar is fully inserted in the ground, injection and drilling are stopped, and the bar is unscrewed from the drill rig.
The second bar can then be coupled to the first bar and the machine, and operation can be resumed.
Rock Bolts: mining, tunneling
Micropiles and Soil Nails: Construction
Features:
Fast drilling and grouting installation
Similar installation methods for all ground conditions
Ability to work with small drill rigs without casing in restricted headroom conditions
High standard of quality control from production stage to installation of the Self-Drilling Hollow Bar Anchor Bolt ensures consistent quality
High yield strength
Good impact strength
Good ductility
Excellent weldability
Balance of Strength & Ductility
Our Onton Steel Drilling anchor Systems comply with the requirements of design following the US standards:
ASTM A615
ASTM F432
AASHTO M 31
FHWA-NHI-14-007(2015)
The Steel Hollow Bar Anchor Bolts can be customized to fulfill different requirements in different areas. And we offer a full-scale stock of all necessary components such as couplings, nuts, drill bits (for various soil conditions), centralizers, and plates.
Components:
Threaded hollow bars (all lengths)
Hollow Bars have a continuous external thread with an R (rope thread) or T (trapezoidal thread) profile.
Technical data serie S460NH High Standard:
| Unit | R25N | R32N | R38N | R51N | T30N | T40N | T52N | T76N | |
| External diameter | mm | 25 | 32 | 38 | 51 | 30 | 40 | 52 | 76 |
| Internal diameter | mm | 14 | 18.5 | 19 | 30.2 | 11 | 16 | 26 | 51 |
| Cross sectional area | mm2 | 300 | 430 | 750 | 1070 | 420 | 879 | 1250 | 1990 |
| Load at 0.2% Yield Fy0.2 | KN | 150 | 230 | 400 | 630 | 260 | 525 | 730 | 1200 |
| Yield Strength Rp0.2 | N/mm2 | 500 | 530 | 530 | 590 | 620 | 590 | 580 | 600 |
| Ultimate load Ful | KN | 200 | 280 | 500 | 800 | 320 | 660 | 930 | 1600 |
| Elongation Agt | % | > 5 | > 5 | > 5 | > 5 | > 5 | > 5 | > 5 | > 5 |
| Weight m | Kg/m | 2.3 | 3.2 | 5.8 | 8.4 | 3.3 | 6.9 | 9.9 | 15.6 |
Couplers
Flexibility in length by using couples. A specially designed stopping system ensures that the coupler is correctly positioned on the bars to be coupled.
Nuts and plates
The plates and nuts are used to create the anchor head. There are straight nuts and spherical nuts, each with their appropriate plates.
Drill bits
Choice of drill bits for different ground conditions.
