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.
Mount Lemmon (O'odham: Babad DoÊ¼ag), with a summit elevation of 9,159 feet (2,792 m), is the highest point in the Santa Catalina Mountains.It is located in the Coronado National Forest north of Tucson, Arizona, United States. dirt access road to the summit on the back side of Mount Lemmon starts in Oracle, which is on state highway 77 northeast of Tucson. It offers a secondary route to the top. This route is popular with off-road 4x4 drivers and with off-road or dual-purpose motorcyclists.