"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." If you plan on drilling into brick, concrete, or stone, you’re going to need to use a masonry drill bit.
Interesting Engineering on MSN
US firm’s record-breaking drill taps granite 387 feet deep to unlock geothermal power
At approximately 387 feet (118 meters), the hole is the deepest ever drilled with millimeter-waves, which are similar to the ...
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