The Cleveland 2120 screw machine length, high-speed steel (HSS) drill bit has a 30-degree helix angle, with a 118-degree drill point and uncoated surface treatment, which is designed for general purpose drilling applications. The shank diameter is the same as the drill size. The 2120 series performs best when drilling into alloy steel, carbon steel, cast iron, aluminum, copper alloys, and brass. The uncoated finish helps increase chip flow in soft materials. Spiral flutes act as a passageway for chip extraction from the hole and for coolant to enter the hole. The twist of the flutes brings chips up and away from the cutting edge. 118-degree drill point is the most common angle with a good comprise of performance across a wide range of materials. Round shanks allow use with a wide variety of tool holding systems. The screw machine length, also called short or stub length has shorter flute and overall length for more rigidity and accuracy. Designed to reduce deflection and breakage than longer length drill bits. Made of HSS, one of the most common tool steels, they offer a good comprise of performance across a wide range of materials and drilling applications and are an economical choice. They can be operated at twice the cutting speed and the cutting edges last longer than carbon-steel. They are made to ANSI and DIN industry standards, which help ensure that drill bits around the world, conform to the same specifications. The tolerances for various aspects of the Cleveland drill bits are: drill diameter range (inches) through 1/8 +0.0000/-0.0005, over 1/8 through 1/4 +0.0000/-0.0007, over 1/4 through 1/2 +0.0000/-0.0010, over 1/2 through 1 +0.0000/-0.0012, over 1 through 2 +0.0000/-0.0015, over 2 through 3 1/2 +0.0000/-0.0020; drill overall length and flute length #80 through 1/8 +0.1250/-0.0626, over 1/8 through 1/2 +0.1250/-0.1250, over 1/2 through 1 +0.2500/-0.1250, over 1 through 2 +0.2500/-0.2500, over 2 through 3 1/2 +0.3750/-0.3750; drill point angle diameter range (inches) 1/16 through 1/2 included angle (degrees) 118 or 135 +/-5 degrees, over 1/2 through 1 1/2 included angle (degrees) 118 +/-3 degrees, over 1 1/2 through 3 1/2 includes angle (degrees) 118 +/- 2 degrees; drill lip height diameter range (inches) 1/16 through 1/8 total indicator variation (inches) 0.0020, over 1/8 through 1/4 total indicator variation (inches) 0.0030, over 1/4 through 1/2 total indicator variation (inches) 0.0040, over 1/2 through 1 total indicator variation (inches) 0.0050, over 1 through 3 1/2 total indicator variation (inches) 0.0060. Drilling, or hole making, is the most common metalworking operation in the world. Twist drill bits are the most common type of drill bit used. Twist drill bits can be used in hand-operated drills, standalone drill presses, or a lathe. Greenfield Industries, which are a part of Top-Eastern Group, is one of the largest manufacturers of twist drills. They also manufacture cutting tools and related products under the following brands: Cleveland, Chicago-Latrobe, Cle-Line, Vermont Tap & Die, Bassett, Putnam Tools, Geo Met RJC, H & G, Vers-O-Tool, and Acme-Fette. The company has locations around the world, and provides tools adhering to ANSI, NAS, and DIN standards.