1.Downhole drilling machine: When drilling a downhole gun hole with a aperture less than 150 mm, in addition to the application of a rock drill, it can also be used to drill a small diameter of 80 ~ 150 mm. When drilling a gun hole with a diameter of less than 70 mm in coal or softer mineral rock, it is generally used to drill or air drill, driven by a motor (or air motor) to drill the drill pipe, and the rock (coal) chips drilled out are discharged through the spiral groove on the drill pipe.
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Heat treatment and surface finishing processes are then employed to enhance the spring's mechanical properties and corrosion resistance Heat treatment and surface finishing processes are then employed to enhance the spring's mechanical properties and corrosion resistance
), and the climate conditions must all be taken into consideration), and the climate conditions must all be taken into consideration
They also find application in roofing, offering shade and protection without obstructing light passage They also find application in roofing, offering shade and protection without obstructing light passage
