As infrastructure projects push into more challenging ground conditions, the demand for high-load geotechnical reinforcement systems continues to rise. SupAnchor, recognized as Asia's No.1 manufacturer and exporter of self-drilling anchors, has introduced a Grade 75 self-drilling hollow anchor variant engineered for heavy-duty applications. The new product extends SupAnchor's self drilling anchor system lineup, offering significantly higher tensile and yield strengths than standard-grade anchors while maintaining the proven drill-and-grout bolt efficiency. Recent large-scale projects in Europe and North America have faced ground conditions where traditional anchoring methods require multiple drilling steps and casing, leading to cost overruns and safety risks. The Grade 75 anchor addresses this by enabling one-pass installation in unconsolidated or cohesive soils.
The new anchor is particularly relevant for projects where standard-grade self drilling anchor bolts fall short on load capacity. By using high-strength Grade 75 steel, the anchor delivers ultimate loads up to 600 kN, making it suitable for deep foundations, heavy tunnel support, and large-scale slope stabilization.
The Grade 75 self-drilling hollow anchor follows SupAnchor's core 3-in-1 integration principle: a single ribbed hollow steel bar acts as sacrificial drilling rod, injection tube, and permanent reinforcing element. This hollow bar anchor design eliminates separate casing systems and speeds up installation in difficult ground. During operation, the bar is rotated with a drill bit attached, and grout is injected through the hollow core as drilling progresses. The grout fills the annular space and penetrates surrounding soil or rock, creating a strong bond while the bar remains in place as permanent reinforcement.
Key technical parameters inferred from SupAnchor's product line logic highlight the strength advantage. Grade 75 steel delivers ultimate loads up to 420 kN for R32 models and 600 kN for R38 models, with yield loads of 340 kN and 480 kN respectively. Cross-sectional areas range from 400 to 650 mm², and rib geometry follows an optimized relative rib area (fR = 0.21–0.33) with 45° angled ribs to minimize splitting forces. At maximum load, crack widths remain below 0.1 mm, ensuring long-term structural stability. Thread profiles comply with ISO 10208 for R-type anchors, and elongation values meet A100 ≥6%, Agt ≥5%, A200 ≥6% for ductility under seismic or dynamic loads.
| 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 (%) | A100 ≥6 / Agt ≥5 / A200 ≥6 | A100 ≥6 / Agt ≥5 / A200 ≥6 |
| Lengths (m) | 2, 3, 4, 5, 6, 7, 8 | 2, 3, 4, 5, 6, 7, 8 |
| Anchor Nut Size | SW46/L65 | SW55/L70 |
| Anchor Coupler Size | D42/L190 | D50/L210 |
| Anchor Plate Size (mm) | 200 x 200 x 12 | 250 x 250 x 16 |
The Grade 75 anchors can be paired with SupAnchor's standard anti-corrosion treatments, including hot-dip galvanizing and SupCoating, to extend service life in damp or moderately corrosive environments. Standardized accessories—nuts, couplers, plates—allow quick on-site connection and reduce construction delays. Because the anchor uses the same thread and rib geometry as other SupAnchor products, contractors can integrate Grade 75 bars into existing self drilling anchor system workflows without specialized training.
Grade 75 self-drilling anchors are designed for projects where standard anchors fall short on load-bearing requirements. In deep foundation reinforcement for high-rise buildings, the higher yield load prevents permanent deformation under sustained dead and live loads. For large-span bridges and industrial heavy machinery anchoring, the 600 kN ultimate capacity of R38 models offers a robust safety margin. A typical application might involve a highway cut in mountainous terrain where the slope exerts lateral pressures exceeding 500 kN per anchor; the R38 Grade 75 model provides the necessary capacity while allowing one-pass drilling through fractured rock.
In tunneling and slope stabilization, the self drilling anchor bolt system excels in complex geological conditions. Deep tunnel excavation—such as highway or railway tunnels through fault zones or soft ground—relies on the anchor's ability to drill and grout simultaneously, reducing overbreak and collapse risk. High and steep slopes with large soil pressure benefit from the high tensile resistance, which counters sliding forces and minimizes surface displacement. Soft soil with high settlement risk, often found in delta regions, also gains stability from the increased load transfer area of the ribbed hollow bar.
The introduction of Grade 75 aligns with growing global investment in transportation, energy, and urban underground space. Industry forecasts indicate a steady expansion of the geotechnical reinforcement system market as aging infrastructure requires retrofitting and new projects demand higher safety factors. The hollow bar anchor technology—particularly with high-strength steel—reduces material usage and installation time compared to conventional rock bolts or soil nails, lowering overall project costs. For mining and tunneling contractors, the drill-and-grout bolt capability means fewer equipment changeovers and safer working conditions. The self drilling anchor system also minimizes the need for casing in collapsing ground, which is a major advantage in alluvial soils or karst formations.
SupAnchor's Grade 75 models provide a reliable option for ground anchor bolt factory supply chains that require consistent quality and load performance. By offering diameters from 25 mm to 51 mm, the product line can match different project scales, from urban deep excavation to large water conservancy structures. This flexibility positions SupAnchor as a soil nail system manufacturer capable of serving diverse geotechnical needs.
SupAnchor has built its reputation as a leading self drilling anchor bolt manufacturer with a strong focus on R&D and international certification. The company's self-drilling anchors comply with ISO 10208 for R-thread profiles and relevant international standards for high-strength structural steel. Its manufacturing processes are supported by rigorous quality control, and the Grade 75 variant benefits from the same standardized thread and rib design proven in projects across Asia, Europe, and the Americas.
By continuously expanding its product portfolio—including R-thread, T-thread, stainless steel, and now Grade 75 high-strength anchors—SupAnchor demonstrates a collaborative approach to meeting diverse geotechnical challenges. The new Grade 75 self-drilling hollow anchor reinforces the brand's message of professional, innovative, and collaborative solutions for the global construction industry. Engineers and contractors seeking a high-capacity geotechnical reinforcement system now have a technically robust and economically viable option for demanding projects.
For further information on SupAnchor's Grade 75 self-drilling hollow anchor and its integration into existing self drilling anchor system workflows, project teams are encouraged to consult the manufacturer's technical documentation.
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