Rock Bolts – Solid Bar
| Physical Properties | Minimum | Typical |
|---|---|---|
| Yield Strength | 500MPa / 160kN | 550MPa / 170kN |
| Tensile Strength | 600MPa / 185kN | 650MPa / 200kN |
| Calculated Shear Strength | 120kN | 130kN |
| Elongation (After Fracture) | 16% | 29% |
| Mass Per Metre | 2.47kg |
| Bar Core Diameter | 20.0mm |
| Major Bar Diameter | 22.1mm |
| Cross Sectional Area | 300mm² |
| Rolled Thread | M24x3.0mm Pitch |
Key Features
- These bolts are manufactured from round bar with "wriggles" on the up hole end which allows a small diameter bolt to mix chemical anchors in standard diameter holes.
- The wriggle bolt is an economic alternate when the tensile strength of larger bolts is not required.
- The rolled thread strength nominally equals the column strength of the bar.
- The wriggle bolt is designed to be used with resin anchors, but can be effectively used with cementitious grouts.
- The wriggle bolt has been found to be effective in coal rib stabilization and mesh retention on rock embankments.
- The nut fitted to wriggle bolts has similar across flats dimensions as nuts fitted to 24mm bolts to utilize standard roof bolt spanners.
- Corrosion protection may be provided by hot dip galvanizing or alternative coatings.
Standard Lengths & Packaging
- Standard bolt lengths range from 600 to 3000mm in 300mm increments.
- Non-standard requirements are available by negotiation.
- Bolts are packaged in bundles with threads protected by heavy duty polyethylene bags.
- Bolt fittings, such as nut and anti-friction washer, are normally supplied fitted to wriggle bolts in the configuration as requested.
Installation Guide Lines
- 35-38mm hole diameters are preferred for the 20mm wriggle bolt.
- Hole depth is critical. Hole depth should be shorter than the bolt to allow for the height of the washer and nut.
- After insertion of the chemical anchors the bolt is rotated through the anchors while being pushed to the back of the hole. Care should be exercised to ensure the bolt is held axially during installation.
- It is important to follow the resin anchors recommended mixing and hold times as printed on the resin anchor cartons.
DO NOT OVER MIX. - For further details regarding installation procedures refer to DSI Underground’s "Practical Guide to Rock Bolting."
