Wegener also noted that the continents move up and down to maintain equilibrium in a process called isostasy. As an example he cited the sinking of Northern Hemisphere lands under the weight of continental ice sheets in the last ice age, and their rise since the ice melted some 10,000 years ago.
Drill that is fitted with a Pipe provides effective connection to the rig surface equipment or application with the bit and the bottom hole assembly for the purpose of pumping the Drill fluid to the bit.
Hammer drills often have a selection switch which allows users to choose between rotary and rotary-plus-hammer modes. When used in rotary mode, a hammer drill can be used for all of the drilling and driving applications that an ordinary drill driver is used for. In rotary-plus-hammer mode, the drill is set to be used on masonry. So when set properly, a hammer drill can almost always bore the hole. If the project requires drilling in masonry, you're going to need the hammer function.