Hydraulic mining rock drill is a kind of mining rock drilling equipment with high-power hydraulic rock drill.  Compared with the traditional pneumatic rock drill, it has the characteristics of high output energy, high efficiency, low energy consumption, and good reliability. Its main supporting tool is the MF rod, whose consumption accounts for 70-75% of the consumption of drill accessories. Therefore, the service life of MF rod directly affects the progress of the project.

Service conditions of MF rods for mining drills

In drilling rock, the female thread end of MF rod is connected to the shank adapter, the male thread end is connected with the female thread of several MF rods to form a rock drilling tools, and the terminal is connected to the threaded button bit, usually drilling holes between 25 ~ 30m. In the drilling, the impact energy and rotary torque output by hydraulic rock drill is effectively transmitted along the drill rod, and finally are transferred to the rock by rock drill bit so that the rock is effectively broken. The rod is subjected to tensile stress, impact vibration, bending stress, and torsional stress caused by the rotation of rod in the rock as the rod rubs or collides violently with the rock wall in the drilling. In addition, during rock drilling, drill rod also needs to circulate a high-pressure water medium in the hole to effectively discharge the rock powder produced by drilling and cooling rock drilling tool. Most of the water is extracted in situ from the water source in the mine, and its acidity is high, which also has a strong corrosive effect on the inner hole wall of drill rod. Therefore, the service conditions of MF rods are quite harsh.

Factors and precautions affecting the service life of MF rods for mining drills

Many factors affect the service life of drill rods in mining drills and the following four factors will have a significant impact on the rock drilling life of drill rods.

1. Quality control of steel smelting and rolling in the manufacturing process of drill rods.

2. Quality control of machining and heat treatment of drill rods.

3. Difference in the hardness of drilled rock formations.

4. The correct control of parameters such as propulsion force, impact power of rock drill, torque of rotating braze, and pressure of flushing water during the operation of drill personnel.

At the same time, the manufacturer should ensure accurate geometry and surface roughness as well as good fitting tolerance for the threaded part machining quality, in addition to ensuring qualified heat treatment quality parameters such as seepage depth, hardness, and wear resistance. When purchasing rock drilling tools, it is best to use rock drilling tools produced by the same company to avoid early failure of the threads of rock drilling tools due to the fit tolerance. In addition, in rock drilling, with the deepening of the drilled hole, the mining drill rod also needs to be continuously lengthened. In loading and unloading drill rods, we should pay attention to the wear and tear of drill rod threads and replace the rods in time.