Heat treated threaded deformed rock bolt is composed of following parts: 1 Bar; 2 Nut; 3 Nylon Washer; 4 Dome Washer; 5 Plate;
L: Length of Bar; l Length of Threaded Portion; m Diameter of Bar
There are 3 major ways of anchoring the rock bolts: mechanical, grouted, and friction. The most common form of mechanically anchored rock bolt uses an expansion shell. A wedge attached to the bolt shank is pulled into a conical expansion shell as the bolt is rotated. This forces the shell to expand against the wall of the borehole. The two mechanisms by which the shell is anchored against the borehole wall are friction and interlock. A preload can be applied to the rock surface by tensioning the bolt with an attached hanger or face plate, which are designed to distribute the load uniformly onto the surrounding rock.
There are 3 major ways of anchoring the rock bolts: mechanical, grouted, and friction. The most common form of mechanically anchored rock bolt uses an expansion shell. A wedge attached to the bolt shank is pulled into a conical expansion shell as the bolt is rotated. This forces the shell to expand against the wall of the borehole. The two mechanisms by which the shell is anchored against the borehole wall are friction and interlock. A preload can be applied to the rock surface by tensioning the bolt with an attached hanger or face plate, which are designed to distribute the load uniformly onto the surrounding rock.
The main function of rock bolt is roof bolting, which is to bind stratified or broken rock layers together to prevent roof falls. In order to achieve this purpose 4 basic theories have been established for roof bolting:
Steel Grade | Yield Strength | Tensile Strength | Elongation After Fracture | Elongation under Max Force | Impact Absorb Energy | |
Rel/MPa | Rm/MPa | A/% | Agt/% | kv2/J | ||
NOT LESS THAN | ||||||
Industrial Standard | MG335/MG400 | 335 | 500 | 15 | 40 | |
MG500 | 500 | 700 | 22 | 100 | ||
Our company Standard | 600 | 600 | 750 | 19 | 9 | 90 |
700 | 700 | 850 | 17 | 7.5 | 80 | |
785 | 785 | 930 | 16 | 5.5 | 60 | |
830 | 830 | 1030 | 15 | 4.5 | 50 |
Suface Type | Nominal Diameter Dn/mm | Nominal Cross SectionSn/m㎡ | Weight per meter g/m | Top strength level MPa |
Levorotation, no longitudinal rib | 16 | 201.06 | 1578 | 800 |
Levorotation, no longitudinal rib | 18 | 254.47 | 1998 | 800/1080 |
Levorotation, no longitudinal rib | 20 | 314.16 | 2466 | 800 |
Levorotation, no longitudinal rib | 22 | 380.13 | 2984 | 800 |
Levorotation, no longitudinal rib | 25 | 490.88 | 3853 | 800/1080 |
Levorotation, no longitudinal rib | 28 | 615.75 | 4834 | 800 |
Levorotation, no longitudinal rib | 32 | 804.25 | 6313 | 800/1080 |
Rock Bolt Tensile Strength | Production Process |
335MPa ~ 500MPa (Medium) | Raw Material — Reduce diameter — Screw thread — Test — Packaging — Stock |
600MPa ~ 700MPa (High) | Raw material — Heat Treatment — Mechanical Property Test — Sawing/Cutting — Reduce diameter — Screw thread — Test — Packaging — Stock |
High Tensile Strength Rock Bolts are applicated in structure and construction projects as follows:
Get In Touch Now!
Our professional team will reply to you within one business day. Please feel free to contact us!
Anyang General International Co., Ltd. is a professional manufacturer and trading company for high-tensile and large-diameter fastners
We are top supplier of high strength steel supplier of anchor cage bolt, rock bolt, structural tie rod in China. Anyang Bolt Fasteners also supplies round bar fabrication services to customers worldwide.