Overview of T76 Full Threaded Steel Self Drilling Rock Bolt
Self drilling anchors are special type of rod anchors. Self-drilling anchor consists of a sacrificial drill bit, hollow steel bar of the appropriate outer and inner diameter and coupling nuts. The anchor body is made of a hollow steel tube with an outer round thread. Steel tube has the sacrificial drill bit at one end and the corresponding nut with a steel end plate. Self drilling anchors are used in a way that hollow steel bar (rod) has a corresponding sacrificial drill bit on its top instead of a classic drill bit.
Specification of Self Drilling Anchor Rods
R25N | R32L | R32N | R32/18.5 | R32S | R32SS | R38N | R38/19 | R51L | R51N | T76N | T76S | |
Outside diameter (mm) | 25 | 32 | 32 | 32 | 32 | 32 | 38 | 38 | 51 | 51 | 76 | 76 |
Internal diameter(mm) | 14 | 22 | 21 | 18.5 | 17 | 15.5 | 21 | 19 | 36 | 33 | 52 | 45 |
External diameter, effective(mm) | 22.5 | 29.1 | 29.1 | 29.1 | 29.1 | 29.1 | 35.7 | 35.7 | 47.8 | 47.8 | 71 | 71 |
Ultimate load capacity (kN) | 200 | 260 | 280 | 280 | 360 | 405 | 500 | 500 | 550 | 800 | 1600 | 1900 |
Yield load capacity (kN) | 150 | 200 | 230 | 230 | 280 | 350 | 400 | 400 | 450 | 630 | 1200 | 1500 |
Tensile strength, Rm(N/mm2) | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 | 800 |
Yield strength, Rp0, 2(N/mm2) | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 | 650 |
Weight (kg/m) | 2.3 | 2.8 | 2.9 | 3.4 | 3.4 | 3.6 | 4.8 | 5.5 | 6.0 | 7.6 | 16.5 | 19.0 |
The advantage and application of Self Drilling Anchor Rods
The function of hollow grouting spiral anchor rod is grouting, so it is also called grouting pipe. It can be rotated in the overall planning to achieve primary pressure. Under pressure, the internal slurry flows out, which not only has a fixed effect on itself, but also enters the anchor hole when the slurry overflows, playing a role in consolidating the surrounding rock. It has its own advantages in application and planning, so it can demonstrate its own advantages in application:
1、 It is precisely under this effect that the initial rapid support effect can be achieved and the deformation of the surrounding rock can be well controlled that a good stability effect can be achieved.
2、 It utilizes a hollow approach in planning, integrating anchor rods and grouting pipes. It is precisely this kind of planning that has great advantages. If it is a traditional grouting pipe, it may cause loss due to back-and-forth pulling, which will not present such a phenomenon.
3、 It can greatly improve the quality of the project, which is precisely because it can achieve a great degree of fullness during grouting, and together with grouting, it can achieve the effect of pressure grouting.
4、 Its neutrality is good. With the addition of other accessories during use, it increases its neutrality, allowing the slurry to wrap the entire hollow anchor rod. It is precisely because of this that rust will not appear during use and can truly achieve long-term use.
5、 It is also very convenient on the device, which is also very important. As long as it is convenient on the device, it can shorten the debugging and construction time. Together with the device, no more screws are needed to meet the requirements of the device nut and pad.