The Cleveland 2331G, also called CLE-MAX 2331G, is a short-length, vanadium steel drill bit with a 30-degree helix angle, a 135-degree point angle, and black oxide surface treatment, for general-purpose drilling applications. The 2331G series was designed for use in the aircraft industry, but is also suitable for other drilling applications. The shank diameter is the same as the drill size. The 2331G drill bit can be used on most materials, but is most suitable for drilling into various steels and cast iron. Black oxide improves lubricity, resists corrosion, and resists flaking. It also helps prevent buildup and welding of material on the tool"s cutting edge when machining iron and steel. Spiral flutes act as a passageway for chip removal and for coolant to enter the hole. The twist of the flutes brings chips up and away from the cutting edge. The 135-degree drill point reduces walking when starting a hole and penetrates more easily than a convention point. Round shanks allow use with a variety of tool holders. Vanadium steel is high-speed steel (HSS) with a high percentage of vanadium, for greater heat resistance and an increased ability to hold an edge over high-speed steel (HSS). This drill bit adheres to Deutsches Institut für Normung (DIN) 1897 standards. The tolerances for various aspects of the Cleveland 2331G drill bit are: drill diameter range through 1/8” +0.0000”/-0.0005”, over 1/8” to 1/4” +0.0000”/-0.0007”, over 1/4” through 1/2” +0.0000”/-0.0010”, over 1/2” to 1” +0.0000”/-0.0012”, over 1” to 2” +0.0000”/-0.0015”, over 2” to 3-1/2” +0.0000”/-0.0020”; drill overall length and flute length #80 through 1/8” +0.1250”/-0.0626”, over 1/8” to 1/2” +0.1250”/-0.1250”, over 1/2” to 1” +0.2500”/-0.1250”, over 1” to 2” +0.2500”/-0.2500”, over 2” to 3-1/2” +0.3750”/-0.3750”; drill point angle diameter range 1/16” to 1/2” included angle 118 or 135 degrees +/-5 degrees, over 1/2” to 1 1/2” included angle 118 degrees +/-3 degrees, over 1-1/2” to 3-1/2” includes angle 118 degrees +/- 2 degrees; drill lip height diameter range 1/16” to 1/8” total indicator variation 0.0020”, over 1/8” to 1/4” total indicator variation 0.0030”, over 1/4” to 1/2” total indicator variation 0.0040”, over 1/2” to 1” total indicator variation 0.0050”, over 1” to 3 1/2” total indicator variation 0.0060”. Drill bits are cutting tools used to make holes in a range of materials. They are used in machines such as handheld portable drills, drill presses, machining centers, and lathes. Drill bits come in a variety of types and lengths. Twist drill bits are the most common type of drill bit. They are a round, twisted shaft, end-cutting tool with two or more cutting edges and two or more flutes. Short length drill bits (also called stub or screw-machine length) are the shortest and stiffest twist bits, helping to reduce the chance of deflection or breakage when drilling. Greenfield Industries manufactures tools under the brand names Cleveland, Chicago-Latrobe, Cle-Line, Vermont Tap & Die, Bassett, Putnam Tools, Geometric, Vers-O-Tool, H & G, and Acme-Fette. The company owned by Top-Eastern Group and headquartered in Seneca, SC, makes tools that meet American National Standards Institute (ANSI), National Aerospace Standard (NAS), and Deutsches Institut für Normung (DIN) standards.