For metal mining, tunnel construction

06 Mar.,2024

 

Product Description

MF47 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.


How do mining friction bolts work?


  • 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.


  • Underground mining Friction Bolt is mainly used to establish ground support when hand-held mining operations are required. 


Mining friction bolts advantages:


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. 


The 47mm friction bolt is suitable for installation with the handheld rock drilling machine (plug/drifting).


Meanwhile, with our advanced PLC-controled auto welder, the bolt will has a very good performance when it is inserted in the rocks.


MF47 FRICTION BOLT-ROCK BOLTS SPECIFICATION AND MECHANICAL PROPERTYDimensionsPhysical PropertiesTechnical DataBolt Diameter A47mmYield StrengthMin. 345 Mpa (120KN)Recommended Normal Bit Size41-45mmBolt Length B0.9-3.0mTypical 445Mpa(150KN)Taper End Diameter C38mmTube Ultimate Tensile StrengthMin. 470 Mpa (160KN)Typical Breaking Capacity178KNTaper Slot Wide D2mmTypical 530Mpa(180KN)Taper Length E100mmMass per Meter2.71 KgsMin. Breaking Capacity133KNBolt Slot Wide F25mmRing Location G8mmCross Section Area345 mm²Recommended Initial Anchorage6-10 Tons               (53-89 KN)Material Guage H3/3.2mmRing Wire Guage I8mmHole Diameter Range43-45.5mmUltimate Axial StrainTypical 21% (Thk<16mm)Ring Open Gap J6-7mm