[City, Country] – [Date] – As global infrastructure demands grow more complex, geotechnical engineers are increasingly turning to advanced reinforcement solutions that combine high load capacity with installation efficiency. SupAnchor, recognized as Asia's No.1 manufacturer and exporter of self-drilling anchors, has responded with the new Grade 75 self-drilling hollow anchor. This high-strength variant of the company's proven self drilling anchor system is designed to meet the rigorous demands of heavy-load applications, offering a reliable alternative where standard ground anchors may fall short.
The Grade 75 hollow bar anchor leverages the well-established 3-in-1 principle: a sacrificial drilling rod, injection tube, and reinforcing bar in a single component. This integration eliminates the need for temporary casing and separate drilling operations, making it particularly effective in unconsolidated or cohesive soils where traditional methods are inefficient and risky. With its superior tensile and yield strength, the anchor opens new possibilities for deep foundation reinforcement, heavy-duty tunnel support, and large-scale slope stabilization.
Consider the challenge of constructing a high-rise tower in a dense urban environment underlain by soft clay and high groundwater. Conventional anchoring methods require multiple steps, increase project duration, and risk borehole collapse. In a recent project involving a 40-story residential complex in a coastal city, engineers needed an anchoring solution that could withstand significant uplift and lateral forces while minimizing disturbance to adjacent structures. SupAnchor supplied its Grade 75 self drilling anchor bolt for the foundation pit support and permanent basement walls. The hollow core allowed simultaneous drilling and grouting, ensuring a strong bond with the surrounding soil and providing immediate load-bearing capacity without the need for casing. This not only accelerated the construction schedule but also enhanced safety by reducing open-hole time.
Similarly, in a highway tunnel project traversing fractured rock and variable ground conditions, the Grade 75 anchors served as forepoling and radial support. The high-strength steel resisted the high bending and shear stresses encountered during excavation, while the 45° ribbed profile minimized splitting forces on the rock mass. The result was a stable tunnel face and reduced overbreak, demonstrating the anchor's adaptability to challenging geological environments.
The Grade 75 self-drilling hollow anchor is built on a ribbed hollow steel bar manufactured from high-strength Grade 75 steel. This material delivers ultimate load capacities significantly higher than standard carbon steel anchors. For the R32 diameter, the anchor achieves an ultimate load of at least 380–420 kN and a yield load of 300–340 kN, while the R38 model offers ultimate loads of 550–600 kN and yield loads of 440–480 kN. These figures represent a substantial increase over conventional R-thread anchors of similar size, enabling engineers to reduce anchor quantities or achieve higher safety factors in critical structures.
The thread profile complies with ISO 10208, ensuring compatibility with standard accessories such as nuts, couplers, and bearing plates. The optimized relative rib area (fR = 0.21–0.33) maximizes bond with cementitious grout, while the 45° inclined ribs transfer load efficiently and reduce splitting forces on the surrounding ground. At maximum load, crack widths remain below 0.1 mm, which is crucial for long-term durability in permanent applications.
Key technical parameters for the initial Grade 75 models are summarized below:
| Parameter | Grade 75 R32 | Grade 75 R38 |
|---|---|---|
| Outside Diameter | 32 mm | 38 mm |
| Internal Diameter | 18–20 mm | 19–21 mm |
| Cross Sectional Area | 400–450 mm² | 600–650 mm² |
| Ultimate Load | ≥380–420 kN | ≥550–600 kN |
| Yield Load | ≥300–340 kN | ≥440–480 kN |
| Weight | 3.2–3.6 kg/m | 4.7–5.1 kg/m |
| Thread Type | ISO 10208 - R32 | ISO 10208 - R38 |
| Steel Grade | Grade 75 high-strength steel | Grade 75 high-strength steel |
| Elongation | A100mm ≥6% / Agt ≥5% / A200mm ≥6% | A100mm ≥6% / Agt ≥5% / A200mm ≥6% |
| Standard Lengths | 2–8 m (in 1 m increments) | 2–8 m (in 1 m increments) |
| Anchor Nut | SW46/L65 | SW55/L70 |
| Anchor Coupler | D42/L190 | D50/L210 |
| Anchor Plate | 200×200×12 mm | 250×250×16 mm |
In addition to strength, the anchor can be supplied with hot-dip galvanizing or SupCoating for corrosion protection, making it suitable for moderately aggressive environments such as damp soils, marine atmospheres, or industrial sites. The standardized lengths (2–8 m in 1-m increments) and compatible accessories ensure rapid on-site assembly, reducing labor intensity and construction delays. The hollow bar design allows for post-grouting if needed, further enhancing bond strength in weak ground.
The Grade 75 anchor is positioned to address a wide range of heavy-load geotechnical applications. In deep foundation engineering, it provides reliable tensile capacity for high-rise buildings, large-span bridges, and industrial machinery foundations. For tunneling and mining, it serves as a robust forepoling and rock reinforcement element in squeezing ground or high-stress environments. Slope stabilization projects benefit from its high yield strength, which resists soil pressure and prevents progressive failure. Permanent anchoring of critical structures—such as nuclear power plant auxiliary buildings, large workshop foundations, and high-pressure pipeline supports—relies on the anchor's long-term structural integrity and low crack width.
The global push for infrastructure renewal and expansion, particularly in North America and Europe, is driving demand for efficient and reliable geotechnical reinforcement systems. Traditional methods often involve multiple specialized components and heavy equipment, leading to high costs and extended schedules. The drill-and-grout bolt approach of the self drilling anchor system simplifies logistics and reduces installation time by up to 50% compared with conventional casing systems. This efficiency, combined with the high load capacity of Grade 75 steel, offers a compelling value proposition for contractors and project owners.
SupAnchor's reputation as a soil nail system manufacturer and ground anchor bolt factory is built on over two decades of innovation and export success. The company holds ISO 9001, ISO 14001, and ISO 45001 certifications, underscoring its commitment to quality, environmental stewardship, and occupational safety. Its manufacturing base in Asia allows cost-effective production without compromising performance, making high-strength anchors accessible to projects worldwide.
The Grade 75 variant complements SupAnchor's existing range, which includes R-thread, T-thread, and stainless steel anchors. By offering a complete portfolio of hollow bar anchors, SupAnchor enables engineers to select the optimal solution for each project's load, corrosion, and installation requirements. The company's global engineering team provides technical support from design to installation, embodying a professional, innovative, and collaborative approach that has earned the trust of contractors and consultants across more than 50 countries.
As infrastructure projects become more ambitious, the need for high-performance geotechnical reinforcement will only grow. SupAnchor's Grade 75 self-drilling hollow anchor represents a strategic advancement, delivering the strength and reliability required for the most demanding applications while maintaining the efficiency and simplicity that define the self drilling anchor bolt concept. With this launch, SupAnchor reaffirms its leadership in the global ground anchor market and its dedication to building a safer, more resilient built environment.
A recent infrastructure project utilized SupAnchor's self drilling anchor system to overcome difficult geology. The hollow bar anchor technology provided efficient ground stabilization, highlighting the company's role in geotechnical reinforcement.
SupAnchor's new Grade 75 self-drilling hollow anchor delivers high tensile strength and yield capacity for heavy-load geotechnical reinforcement, with standardized threads and corrosion protection.
A large-scale highway expansion in the Alps is using SupAnchor's self-drilling anchor system to tackle complex geology, ensuring slope stability and project efficiency.
SupAnchor's Grade 75 self-drilling hollow anchor bars, with continuous T-thread and ASTM A615 compliance, provide reliable geotechnical reinforcement for a hydropower station slope stabilization project.
A recent infrastructure project demonstrates advanced geotechnical reinforcement using SupAnchor's self drilling anchor system in challenging slope conditions, improving safety and efficiency.
