Amana Tool's 4 facet jobber length fractional drills consist of 2 cutting edges with 2 facets per cutting edge. The facets consist of the lip relief and the lip clearance angle. Multi-faceted drill geometries translate into improved centering accuracy, thereby producing rounder, precise holes less likely for "bell mouthing. " Our premium grade carbide substrate insures increased tool life by a minimum factor of 10X's over HSS coated bits, all while often eliminating the need for a prior center punch or spotting procedure. Also good for drill press. Excellent for: Aluminum, Aluminum 5052, Aluminum Alloys, Aluminum Alloyed Si > 10%, ACM, Brass, Bronze, Copper, Copper Alloys, Fomex with Aluminum Face, Steels, Tool SteelsFree Machining Stainless Steels, Soft Cast Irons, Medium Cast Irons, Malleable Cast Irons, Magnesium, Nickel Alloys, Low Carbon Steels, Medium Carbon Steels, High Tensile (35-45 Rc) Steels, High Tensile (45+ Rc) Steels, Soft Titanium, Titanium Alloys Hard TitaniumMore sizes and types (Letter, Number & Metric) available upon request. Router collet reducer RB-102 (1/4 to 1/8) available for 1/8 shank bits.