A countersink is a tapered hole drilled with a wide outer portion. A common usage is to allow the head of a countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface of the surrounding material. (By comparison, a counterbore makes a flat-bottomed hole that might be used with a hex-headed capscrew.) A countersink may also be used to remove the burr left from a drilling or tapping operation thereby improving the finish of the product and removing any hazardous sharp edges. Two types of counter bores A counterbore can refer to a cylindrical flat-bottomed hole, which enlarges another hole, or the tool used to create that feature. ... Burr or Bur may refer to: In certain species of plants, burr is a seed or dry fruit in which the seeds bear hooks or teeth which attach themselves to fur or clothing of passing animals or people. ... Taps and dies are metalworking tools for the creation (cutting) of screw threads in metal parts. ...

Cross hole countersink cutter

Side and end view of a cross hole deburrer

A cross hole countersink is a cone-shaped tool with a cutting edge provided by a hole that goes through the side of the cone (see picture at right). The intersection of the hole and cone form the cutting edge on the tool. The cone is not truly symmetrical as it is essential that the cone retreats away from the cutting edge as the tool rotates. If this does not occur the cutting edge will lack clearance and rub rather than bite into the material. This clearance is referred to as cutting relief. Image File history File links Download high-resolution version (804x1038, 133 KB)Photograph taken by Glenn McKechnie on the 24th March 2005. ... Image File history File links Download high-resolution version (804x1038, 133 KB)Photograph taken by Glenn McKechnie on the 24th March 2005. ...

These tools are best used as deburring tools, where the burr from a previous machining operation needs to be removed for cosmetic and safety reasons, however they may be used in softer materials (such as wood or plastic) to create a countersunk hole for a screw.

Fluted countersink cutter

Side and end view of a 4 fluted countersink

The fluted countersink cutter is used to provide a heavy chamfer in the entrance to a drilled hole. This may be required to allow the correct seating for a countersunk head screw or to provide the lead in for a second machining operation such as tapping. Countersink cutters are manufactured with two common angles, 90° and 82°. This difference provides a choice in seating angles for the mating part. Image File history File links Download high resolution version (954x1023, 156 KB)Photograph taken by Glenn McKechnie on the 24th March 2005. ... Image File history File links Download high resolution version (954x1023, 156 KB)Photograph taken by Glenn McKechnie on the 24th March 2005. ... Example of a chamfer A Chamfer is a beveled edge connecting two surfaces. ... Screws come in a variety of shapes and sizes for different purposes. ... Taps and dies are metalworking tools for the creation (cutting) of screw threads in metal parts. ...

Better quality fluted countersink cutters will have the flutes (or at least one flute) at an irregular pitching. This variation in pitching reduces the chance of the cutting edges setting up a harmonic action and leaving an undulated surface. This surface ripple is also dependent on the surface speed of the cutting edges, material type and applied pressure; once started it is hard to remove. In acoustics and telecommunication, the harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency. ...

Metalworking:
Metalworking cutting tools: Image File history File links Blacksmith-hammer-anvil-50x50. ... This article or section is in need of attention from an expert on the subject. ...	Broach | Burr | Chisel | Counterbore | Countersink | Cutting tool | End mill | Metalwork file | File | Hand scraper | High speed steel | Milling cutter | Reamer | Stellite | Tipped tool | Tool bit A push style 5/16 keyway broach A broach is a series of chisel points mounted on one piece of steel. ... A selection of carbide burrs Burrs are small cutters used in die grinders, rotary tools or dentists drills. ... Steel woodworking chisel. ... Two types of counter bores A counterbore can refer to a cylindrical flat-bottomed hole, which enlarges another hole, or the tool used to create that feature. ... a Cutting Tool, in the context of Metalworking is any tool that is used to remove metal from the workpiece by means of shear deformation. ... Several types of endmills An endmill is a type of Milling cutter, a cutting tool used in industrial milling applications. ... A File (or Hand-File) is a metalworking hand tool used to shape material by abrasion. ... Detail of a double-cut flat file A file is a hand tool consisting of a steel shaft whose surface is cut with sharp parallel ridges made by a chisel before the file is hardened. ... Three different engineering hand scrapers A hand scraper is a single-edged tool used to scrape metal from a surface. ... High speed steel (HSS) is a material usually used in the manufacture of machine tool bits and cutters. ... Milling cutters are cutting tools used in milling machines or machining centres. ... A reamer or ream is a tool for enlarging holes and is used in metalworking. ... Stellite is a range of cobalt-chromium alloys designed for wear resistance. ... A tipped tool or insert generally refers to any cutting tool where the cutting edge consists of a seperate piece of material, either brazed or clamped on to a seperate body. ... A tool bit generally refers to a plain High Speed Steel (HSS) tool. ...
Metalworking topics:   Casting | CNC | Cutting tools | Drilling and threading | Fabrication | Finishing | Grinding | Jewellery | Lathe (tool) | Machining | Machine tooling | Measuring | Metalworking | Hand tools | Metallurgy | Milling | Occupations | Press tools | Smithing | Terminology | Welding This article or section is in need of attention from an expert on the subject. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... A CNC Turning Center A CNC Milling Machine The abbreviation CNC stands for Computer Numerical Control, and refers specifically to a computer controller that reads G-code instructions and drives the machine tool, a powered mechanical device typically used to fabricate metal components by the selective removal of metal. ... a Cutting Tool, in the context of Metalworking is any tool that is used to remove metal from the workpiece by means of shear deformation. ... Drilling is the process of using a drill bit in a drill to produce holes. ... A typical steel fabrication shop Fabrication is an industrial term generally applied to the building of metal machines and structures. ... Metalworking finishing is the activity of making things out of metal in a skillful manner. ... Rotating abrasive wheel on a bench grinder. ... Jewellery (jewelry in American English) is any piece of fine material used to adorn the human body. ... Conventional metalworking lathe In woodturning, metalworking, metal spinning, and glassworking, a lathe is a machine tool which spins a block of material so that when abrasive, cutting, or deformation tools are applied to the block, it can be shaped to produce an object which has rotational symmetry about an axis... A lathe is a common tool used in machining. ... A machine tool is a powered mechanical device, typically used to fabricate metal components of machines by the selective removal of metal. ... The examples and perspective in this article or section may not represent a worldwide view. ... This article or section is in need of attention from an expert on the subject. ... Metalworking hand tools are hand tools that are used in the metalworking field. ... Metallurgy is a domain of materials science and of materials engineering that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their mixtures, which are called alloys. ... Cutters for a milling machine. ... It has been suggested that this article or section be merged with Smith (metalwork). ... Power press with a fixed barrier guard A press, or a machine press is a tool used to work metal (typically steel) by changing its shape and internal structure. ... A smith, or metalsmith, is a person involved in the shaping of metal objects. ... This article needs to be wikified. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ...