R51 Self-Drilling Anchor Bolt
The R51 Self-Drilling Anchor Bolt is an ultra-large-diameter, high-performance heavy-duty anchoring and ground support material.
Introduction
The R51 Self-Drilling Anchor Bolt is an ultra-large-diameter, high-performance heavy-duty anchoring and ground support material. As an engineering-grade heavy-load self-drilling anchor bolt, it is different from conventional small and medium-diameter support bolts, focusing on ultra-deep anchoring, extremely high load-bearing capacity, and reinforcement of heavily fractured rock masses.
Developed specifically for major engineering projects involving large cross-sections, deep-buried high-stress conditions, and extremely complex geological environments, the R51 represents the highest load-bearing capacity and support level among conventional R-series self-drilling anchor bolts. It is widely used in high-risk, high-difficulty, and high-standard specialized anchoring and reinforcement projects.
Product Specifications
Hollow Anchor Bar
| Size | Outer Dia. | Ultimate Load | Yield Load | Weight | |||||
| mm | in | kN | kips | kN | kips | kg/m | lbs/ft | ||
 |
SSR51N | 51 | 2.01 | 800 | 180 | 630 | 142 | 9.00 | 6.05 |
| SER51L | 51 | 2.01 | 550 | 124 | 450 | 101 | 6.20 | 4.17 | |
| SER51L1 | 51 | 2.01 | 660 | 149 | 540 | 122 | 6.75 | 4.54 | |
| SER51N | 51 | 2.01 | 800 | 180 | 630 | 142 | 8.20 | 5.51 | |
| SER51S | 51 | 2.01 | 925 | 208 | 740 | 167 | 9.25 | 6.22 | |
| Note： 1. Customized products are available based on your specific requirements； 2. 1mm=0.03937in 1kN=0.225kips 1MPa=0.1450377ksi 1kg/m=0.672 lbs/ft |
|||||||||
Coupler
| Size | Outer Dia. | Length | Weight | Note | |||||
| mm | in | mm | in | kg | lbs | ||||
 |
SSR51 | 63 | 2.48 | 200 | 7.87 | 1.85 | 4.07 | With sealing ring | |
| 63 | 2.48 | 220 | 8.66 | 2.00 | 4.40 | ||||
| 63 | 2.48 | 260 | 10.24 | 2.50 | 5.50 | ||||
| SER51 | 63 | 2.48 | 200 | 7.87 | 1.84 | 4.05 | Without sealing ring | ||
| 63 | 2.48 | 220 | 8.66 | 2.03 | 4.47 | ||||
| 63 | 2.48 | 260 | 10.24 | 2.51 | 5.52 | ||||
Hex Nut
| Size | Key Size | Length | Weight | Note | |||||
| mm | in | mm | in | kg | lbs | ||||
 |
SSR51 | 75 | 2.95 | 70 | 2.76 | 1.53 | 3.37 | Heat treatment | |
| 75 | 2.95 | 80 | 3.15 | 1.84 | 4.05 | ||||
| 75 | 2.95 | 130 | 5.12 | 3.05 | 6.71 | ||||
Domed Nut
| Size | Key Size | Length | Weight | Note | |||||
| mm | in | mm | in | kg | lbs | ||||
 |
SSR51 | 75 | 2.95 | 70 | 2.76 | 1.60 | 3.52 | Heat treatment | |
| 75 | 2.95 | 80 | 3.15 | 1.82 | 4.00 | ||||
| 75 | 2.95 | 100 | 3.94 | 2.28 | 5.02 | ||||
Flat Plate
| Size | Dimensions | Thickness | Hole Dia. | Weight | |||||
| mm | in | mm | in | mm | in | kg | lbs | ||
 |
SER51 | 200×200 | 7.87×7.87 | 30 | 1.18 | 60 | 2.36 | 8.72 | 19.18 |
| 250×250 | 9.84×9.84 | 40 | 1.57 | 60 | 2.36 | 18.90 | 41.58 | ||
Centralizer
| Size | Outer Dia. | Length | Weight | ||||
| mm | in | mm | in | kg | lbs | ||
 |
SER51 | 91 | 3.58 | 30 | 1.18 | 0.30 | 0.66 |
Drill Bit
| Size | Outer Dia. | Application (Advice) | ||||||
| mm | in | |||||||
 |
EX | Sand, fills, gravel | ||||||
| SSR51/90 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/100 | 100 | 3.94 | ||||||
| SSR51/110 | 110 | 4.33 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
| SSR51/150 | 150 | 5.91 | ||||||
| SSR51/175 | 175 | 6.89 | ||||||
 |
EXX | Softer sedimentary rocks such as marls, mudstones, siltstone | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/100 | 100 | 3.94 | ||||||
| SSR51/110 | 110 | 4.33 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
| SSR51/150 | 150 | 5.91 | ||||||
| SSR51/200 | 200 | 7.87 | ||||||
 |
EXX(Venturi) | |||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/140 | 140 | 5.51 | ||||||
 |
Clay Bit | Clay, soft soil, marls, loose sand or gravel | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
| SSR51/150 | 150 | 5.91 | ||||||
| SSR51/175 | 175 | 6.89 | ||||||
| SSR51/200 | 200 | 7.87 | ||||||
| SSR51/250 | 250 | 9.84 | ||||||
 |
ES-F | Gravel, soft rock | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/100 | 100 | 3.94 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
 |
ESS-F | Weathered rock, stone walls, rubble | ||||||
| SSR51/70 | 70 | 2.76 | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/100 | 100 | 3.94 | ||||||
| SSR51/110 | 110 | 4.33 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
| SSR51/150 | 150 | 5.91 | ||||||
 |
EY | Chalk, gravel | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
 |
EYY | Competent ground, strong rock | ||||||
| SSR51/76 | 76 | 2.99 | ||||||
| SSR51/90 | 90 | 3.54 | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
 |
EC | Chalks, marls, fills, competent ground | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
 |
XX | Sand, clay, fills, gravel | ||||||
| SSR51/110 | 110 | 4.33 | ||||||
| SSR51/130 | 130 | 5.12 | ||||||
| SSR51/150 | 150 | 5.91 | ||||||
| SSR51/200 | 200 | 7.87 | ||||||
 |
ES-D | Gravel, soft rock | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
 |
ESS-D | Weathered rock, stone walls, rubble | ||||||
| SSR51/115 | 115 | 4.53 | ||||||
Features
1. Ultra-Large Grouting Channel for Deep Rock Mass Reinforcement
Compared with small-diameter rock bolts, the R51 self-drilling anchor bolt features an ultra-large hollow grouting channel, providing higher grouting flow, faster penetration, and a wider diffusion range.
It enables deep-hole grouting and large-scale fracture filling and consolidation in surrounding rock. The grout can penetrate deep into internal rock fractures, firmly bonding loose rock masses and fractured formations with the self-drilling anchor bolt to form a thick, high-strength composite reinforcement zone.
This significantly improves the overall stability of deep surrounding rock from the source and enhances long-term support performance.
2. Designed for Extreme Geological Conditions
The R51 self-drilling anchor bolt is specially designed for high-risk geological conditions, including collapse-prone formations, highly fractured rock masses, water-rich strata with groundwater inflow, and areas with severe stress concentration.
Without complicated pre-treatment procedures, it enables an integrated construction process of drilling, grouting, and anchoring in one operation.
By effectively addressing engineering challenges such as deep rock mass instability, sliding deformation, and water-related deterioration, the R51 provides a reliable core support solution for extremely complex and high-risk geotechnical environments.
