MF39 Friction Bolts are rock bolts with only 2 parts, a tube and matching domed bearing plate. The high strength steel tube is slotted along its length. One end is tapered for easy insertion into a drill hole and the other has a welded ring flange to hold the bearing plate.
With the bearing plate in place, the tube is driven into a slightly smaller hole, using the same standard percussion drill that made the hole.
As the tube of the rock bolt slides into place, the full length of the slot narrows, causing radial pressure to be exerted against the rock over its full contact length.
MF39 Split Set Bolt is mainly used to establish ground support when hand-held mining operations are required. Our MF47 Split Set Bolt was made by high strength steel strip which special refined with very low level of Si & P in chemical components, it will make the bolt in perfect performance of supporting rocks, and help to have a good quality in galvanizing. Meanwhile, with our advanced PLC-controled auto welder, the bolt will has a very good performance when it is inserted in the rocks.
| MF39 FRICTION BOLT-ROCK BOLTS SPECIFICATION AND MECHANICAL PROPERTY | ||||||
| Dimensions | Physical Properties | Technical Data | ||||
| Bolt Diameter | A | 39mm | Yield Strength | Min. 345 Mpa (85KN) | Recommended Normal Bit Size | 35-38mm |
| Bolt Length | B | 0.6-2.4m | Typical 445Mpa(110KN) | |||
| Taper End Diameter | C | 30mm | Tube Ultimate Tensile Strength | Min. 470 Mpa (115KN) | Typical Breaking Capacity | 124KN |
| Taper Slot Wide | D | 2mm | Typical 530Mpa(130KN) | |||
| Taper Length | E | 65mm | Mass per Meter | 1.92 Kgs | Min. Breaking Capacity | 89KN |
| Bolt Slot Wide | F | 17mm | ||||
| Ring Location | G | 3mm | Cross Section Area | 245 mm² | Recommended Initial Anchorage | 3-6 Tons (27-53 KN) |
| Material Guage | H | 2/2.5mm | ||||
| Ring Wire Guage | I | 6mm | Hole Diameter Range | 35-38mm | Ultimate Axial Strain | Typical 21% (Thk<16mm) |
| Ring Open Gap | J | 5-6mm | ||||
