Holes that qualify as âdeep-hole drilling are three or more drill bit diameters. deep. When drilling this deep, the speed and feed rate must be adjusted to. reduce friction. Friction creates heat, and heat build-up in the drill bit can cause. failure and breakage. Lubricants help dissipate heat from the tip of the drill bit, prolonging drill life, and should always be used when deep-hole drilling.
Humphry's Peak (not to be confused with Mt Humphrey's in the Sierra) in the Coconino National Forest, is the tallest summit in all of Arizona. It is part of the San Francisco Peaks, a volcanic mountain range 9 miles north of Flagstaff, Arizona.
The point where Utah, Colorado, New Mexico, and Arizona meet is called  Four Corners and is unique among the states. Arizona base map, Courtesy of Maps.com. This elevation map of Arizona illustrates the number of feet or meters the state rises above sea level. The lowest areas of the state are along the Colorado River where a low point of 70 feet above sea level is reached. The highest point in Arizona is in the northern part of the state.