Top Chinese supplier of wind turbine founation anchor bolt.

Heat-treated Threaded Deformed Rock Bolt

Heat Treated Thread Deformed Bar - Rock Bolt Parts

Components of Heat Treated Threaded Deformed Bar Rock Bolt

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

Anchoring Ways of Rock Bolt

Heat Treated Threaded Deformed Bar Rock Bolt

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.

Rock Bolt Safety Certificates

Rock Bolt for Roof Bolting Support

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:

  • Simple skin support;
  • Suspension of a thin roof layer from a massive bed;
  • Beam building of laminated strata;
  • Keying of highly fractured and blocky rock mass.

Mechenical Properties of Threaded Deformed Rock Bolt

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

Available Dimensions of Threaded Deformed Rock Bolt

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

Production Process Compare of High and Medium Tensile Rock Bolt:

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

Application of Threaded Deformed Rock Bolt :

High Tensile Strength Rock Bolts are applicated in structure and construction projects as follows:

  • Coal mining
  • Hard rock mining
  • Civil construction
  • General construction
  • Geotechnical and Shoreline
  • Bridges
  • Dams
  • Infrastructure
  • Tunnels
Top