The Micro Oil Screw Air Compressor uses two rotors (screws) that rotate in opposite directions. As the screws turn, air is drawn in and compressed. The oil injected into the system lubricates and cools the compressor element while also sealing the gap between the screws.
[pdf] The price range for a basic borehole drilling machine can vary significantly. On average, you can expect to pay anywhere from $3,000 to $30,000 for a basic machine. This price range includes both handheld and mounted machines, with the latter being more expensive.
[pdf] A rotary drilling rig is a construction machinesuitable for hole-forming operations in building foundation engineering. It is mainly suitable for sandy soil, cohesive soil, silty soil, fill layer, and silt layer, so.
[pdf] 
