In the rugged terrain of a trans‑European highway project, engineers faced a daunting task: stabilizing a 120‑meter‑high slope composed of fractured shale and soft clay layers. Traditional drilling and anchoring methods proved slow and unreliable, with casing systems frequently jamming in the loose overburden. The project demanded a geotechnical reinforcement system that could combine rapid installation with exceptional load‑bearing capacity—exactly what the new Grade 75 self‑drilling hollow anchor from SupAnchor delivers.
SupAnchor, recognized as Asia’s No. 1 manufacturer and exporter of self‑drilling anchors, has expanded its product line with this high‑strength variant. The Grade 75 anchor retains the proven “3‑in‑1 principle” – sacrificial drill rod, injection tube, and reinforcing bar all in one – while elevating tensile and yield strengths to meet the demands of heavy‑duty infrastructure, deep tunnels, and critical permanent support structures.
The heart of the Grade 75 self‑drilling anchor system is a ribbed hollow steel bar made from high‑strength Grade 75 steel. This material choice pushes ultimate and yield loads significantly beyond standard carbon steel grades, making it a premier hollow bar anchor solution. Based on SupAnchor’s established threading and rib design, two common diameter models – R32 and R38 – illustrate the performance leap:
| Parameter | Grade 75 R32 Model | Grade 75 R38 Model |
|---|---|---|
| Outside Diameter (mm) | 32 | 38 |
| Internal Diameter (mm) | 18–20 | 19–21 |
| Cross Sectional Area (mm²) | 400–450 | 600–650 |
| Ultimate Load (kN) | ≥380–420 | ≥550–600 |
| Yield Load (kN) | ≥300–340 | ≥440–480 |
| Weight (kg/m) | 3.2–3.6 | 4.7–5.1 |
| Thread Type | ISO 10208 – R32 | ISO 10208 – R38 |
| Elongation (%) | A100mm ≥6% / Agt ≥5% | A100mm ≥6% / Agt ≥5% |
| Standard Lengths (m) | x2, x3, x4, x5, x6, x7, x8 | x2, x3, x4, x5, x6, x7, x8 |
These self drilling anchor bolt specifications translate directly into site‑ready value. The optimized rib area (fR = 0.21–0.33) maximizes grout bond, while 45° angled ribs minimize splitting forces on the surrounding ground. At maximum load, crack widths remain below 0.1 mm, ensuring structural integrity. The anchors are compatible with standard accessories – nuts, couplers, and plates – allowing crews to quickly connect and install the drill-and-grout bolt without specialized tooling, a crucial advantage in remote or logistically constrained sites.
The Grade 75 self‑drilling anchor system is tailored for the most demanding geotechnical challenges:
In all these contexts, the Grade 75 anchor eliminates the need for casing recovery or separate injection tubes, slashing installation time by up to 50% compared to conventional methods. For a hollow bar anchor system, this speed is matched by the confidence of pushing ultimate loads past 400 kN in a 32‑mm bar – previously achievable only with larger diameters.
The global geotechnical engineering market is projected to grow at 6.8% CAGR through 2030, driven by urbanization, transport network expansion, and renewable energy foundations. Engineers and contractors are increasingly seeking integrated solutions that reduce risk and accelerate programs. The Grade 75 self‑drilling anchor answers this need by offering self drilling anchor system that marries high strength with on‑site versatility.
Its compliance with ISO 10208 thread standards ensures interchangeability with existing R‑thread accessories, while the use of high‑strength steel aligns with Eurocode 7 and North American LRFD design methodologies. This makes adoption seamless for design consultants and allows owners to specify a geotechnical reinforcement system that fits within existing QA/QC frameworks. The anchor’s ribbed geometry also improves grout‑ground interface, reducing the number of anchors required and lowering overall material costs – a compelling value proposition for public infrastructure budgets.
As the leading ground anchor bolt factory in Asia, SupAnchor has supplied self‑drilling anchors to over 60 countries, including landmark projects such as the Doha Metro, Singapore’s Deep Tunnel Sewerage System, and high‑speed rail lines in Southeast Asia. The Grade 75 variant is the latest result of continuous R&D investment, tested to meet the most rigorous elongation and fatigue standards.
“Our clients told us they loved the speed of our standard self‑drilling anchors but needed higher tensile capacity for permanent structures,” explains SupAnchor’s Chief Engineer. “Grade 75 closes that gap, delivering up to 30% more ultimate load without compromising the 3‑in‑1 installation workflow.” Every anchor undergoes in‑line dimensional checks and destructive testing on sample lots, ensuring that the self drilling anchor bolt leaving the factory performs exactly as designed.
With stocks available in standard lengths and custom manufacturing for large‑scale contracts, the Grade 75 series is poised to become the default choice for consultants specifying hollow bar anchors in high‑load applications. For more information or to request a technical datasheet, visit SupAnchor.com.
SupAnchor introduces Grade 75 self-drilling hollow anchors, a high-strength geotechnical reinforcement system designed for deep foundations, tunnels, and slope stabilization in complex conditions.
SupAnchor's self-drilling anchor system deployed in a complex European tunnel project overcomes water-rich fractured rock, highlighting industry-leading hollow bar anchor technology and ground stabilization.
SupAnchor's new patented GFRP friction bolt offers superior corrosion resistance, lightweight design, and non-sparking safety for mining and tunneling projects, replacing traditional steel bolts in aggressive environments.
A major urban infrastructure project successfully employed SupAnchor’s self drilling anchor system to overcome unstable ground conditions, demonstrating advanced geotechnical reinforcement technology.
SupAnchor introduces the SupShell Expansion Rock Bolt System, providing immediate anchorage and efficient grouting for geotechnical reinforcement in mines, tunnels, and infrastructure.
