how deep is the deepest hole ever drilled by man?
Drilling began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig. Boreholes were drilled by branching from a central hole. The deepest, SG-3, reached 12,262 metres (40,230 ft) in 1989 and still is the deepest artificial point on Earth. The borehole is 9 inches (23 cm) in diameter. In terms of true depth, it is the deepest borehole in the world.