A push style 5/16" keyway broach

The action of broaching is fundamentally one of removing material via a linear shearing or scraping action, as opposed to milling in which the cutting action is rotary. Image File history File links Download high resolution version (1839x486, 133 KB) Photograph taken by Glenn McKechnie on the 26th March 2005. ... Image File history File links Download high resolution version (1839x486, 133 KB) Photograph taken by Glenn McKechnie on the 26th March 2005. ... Milling may refer to: Grinding grain and other materials in a mill Cutting and shaping materials into products with milling machines Miller Category: ...

A broach is a series of progressively taller chisel points mounted on a single piece of steel, typically used to enlarge a circular hole into a larger noncircular shape such as a square or other desired shape. This article is about the tool. ... For other uses, see Steel (disambiguation). ...

Another typical use of a broach is to cut splines or a square keyway (see image) on objects such as gears, driveshafts, pulleys etc. The amount of material removed by each broach tooth (or chisel) varies with the material being cut. A broach tooth designed to cut steel might remove only 0.05 mm (0.0025 inch), while a broach tooth designed to cut brass might remove as much as 0.10 mm (0.004 inch). The succession of teeth (chisels) removes the total amount of material required. A broach may also be designed to be pushed or pulled through an existing hole; broaching machines are therefore designed accordingly. A spline consists of a long strip of wood (a lath, not to be confused with lathe) fixed in position at a number of points. ... For other uses, see Gear (disambiguation). ... This article is about the mechanical device. ... For the band, see Pulley (band). ... A millimetre (American spelling: millimeter), symbol mm is an SI unit of length that is equal to one thousandth of a metre. ... An inch (plural: inches; symbol or abbreviation: in or, sometimes, ″ - a double prime) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. ... Brazen redirects here. ...

Wobble or Rotary Broach

A somewhat different design of tool that can achieve the irregular hole shape of a broach is called a wobble broach. This type of tool is often used on rotating machines such as lathes. The wobble broaching process is also called rotary broaching. Center lathe with DRO and chuck guard. ...

The tool has a contour similar to the desired final shape but the leading edge of the tool is wider than the body. The tool is free to rotate but the axis of rotation is inclined slightly to the axis of rotation of the work. A typical value for this misalignment is 1 degree. As the work rotates, the broach is pressed against it and rotates synchronously with it. However, since the axis of rotation is different, the leading (cutting) edge of the broach "wobbles" with respect to the work.

If the tool is inclined at an angle of 1 degree to the work, the sides of the tool must have a 1 degree or greater draft.

Ideally the tool advances at the same rate that it cuts. So a 1/2" diameter tool should advance at 0.009" per revolution.

If it advances any faster than that then the tool becomes choked, if it advances any more slowly then you get an interrupted or zig-zag cut. Since all work material is elastic, you would actually cut a little less than the ideal rate just to release the load on the non-cutting edge of the tool.

There is some spiraling of the tool as it cuts so the bottom of the hole may be rotated with respect to the top of the hole. Spiraling may be undesirable because it binds the body of the tool and prevents it from wobbling freely. One solution to this is to reverse the rotation in mid cut causing the tool to spiral in the opposite direction. If reversing the machine is not practical, then interrupting the cut is another possible solution.

In general, a wobble broach will not cut as accurately as a push or pull broach. However, the ability to use a wobble broach on high production machinery such as a screw machine makes this a desirable manufacturing method. General Brown & Sharpe Single Spindle Screw Machine. ...

External links

• Commercial video of Rotary Broaching

v • d • e Cutting tools in metalworking Cutting tools Broach · Burr · Chisel · Counterbore · Countersink · End mill · File · Hand scraper · Milling cutter · Reamer · Tipped tool · Tool bit Image File history File links Blacksmith-hammer-anvil-50x50. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ... A selection of carbide burrs Burrs are small cutters used in die grinders, rotary tools or dentists drills. ... This article is about the tool. ... 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 countersink is a tapered hole drilled with a wide outer portion. ... Several types of endmills An endmill is a type of Milling cutter, a cutting tool used in industrial milling applications. ... Detail of a double-cut flat file A file (or hand-file) is a hand tool used to shape material by cutting. ... Three different engineering hand scrapers A hand scraper is a single-edged tool used to scrape metal from a surface. ... 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. ... 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 · Forging · Grinding · Jewellery · Lathe · Machining · Machine tooling · Measuring · Metalworking · Hand tools · Metallurgy · Milling · Occupations · Press tools · Pipe and tube bending · Smithing · Turning · General terminology · Welding This article is about the manufacturing process. ... For other uses, see CNC (disambiguation). ... 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, when used as an industrial term, applies to the building of machines , structures, process equipment for chemical, fertilizer sector by cutting, shaping and assembling components made from raw materials. ... This article is about smithing. ... Rotating abrasive wheel on a bench grinder. ... For the Korean music group, see Jewelry (group). ... Center lathe with DRO and chuck guard. ... 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. ... Turned chess pieces Metalworking is the craft and practice of working with metals to create structures or machine parts. ... Metalworking hand tools are hand tools that are used in the metalworking field. ... Georg Agricola, author of De re metallica, an important early book on metal extraction Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their compounds, which are called alloys. ... Endmills 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. ... Turning, CNC turning, or manual turning is the process used to produce cylindrical components in a lathe. ... This article needs to be wikified. ... Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. ...