The Machining Encyclopedia

Many common terms have different meanings when they are mentioned in the machining space. For example, if you look up in the dictionary the word “Turning,” you will get the definition “the act of a person or thing that turns”. In machining, it means an operation performed on a lathe. Other terms have the same meaning, but the focus is very different when strictly within the machining jargon. A good example is the word “Speed”, which maintains its origin but has a particular angle (Cutting Speed) when spoken by a machinist. The Machining Doctor’s Glossary gives you the definitions of each term in the machining industry.

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  • Advanced Cutting Materials
    Advanced Cutting Materials in machining refers to CBN, PCD, and Ceramic-based inserts. The common property between them is that they are harder than carbide grades, and therefore provide unique solutions to machine exotic materials and hardened steel. Read More
  • Alloying Elements for Machining
    Alloying element is a chemical element added to the primary substance of the material (in most cases ferrous) to tweak and enhance mechanical, metallurgical, and physical properties to suit different engineering needs. Read More
  • Low Alloy Steel
    There is no scientific definition, but in practice, alloyy steels are carbon steels with additional alloying elements (on top of the carbon and Manganese) of up to 5%. These elements are added to improve the strength, toughness, corrosion resistance, wear resistance, hardenability, and the(...) Read More
  • Aluminium Wheel
    Aluminum in machining is referring to Aluminum alloys made from Aluminum (Al), with additional alloys that are usually silicon (Si), copper (Cu), magnesium (Mg), and manganese (Mn). Aluminum is a popular engineering material due to its low density (2.5 times lower than steel) and high(...) Read More
  • PMK ISO material groups
    A common format to describe the Application Range of a given Grade. Letter - Raw material: P - Steel M - Stainless Steel K - Cast Iron N- Non-ferous S - Superalloys H - Hardened Steel. Numbers:5 to 45 represnts how "difficult" is the application. 05 - Most Favorable 45- Least favorable Read More
  • Approach/Entry Angle
    In machining, the approach (or entry) angle is when the cutting edge is engaged with the material in the feed's direction. The effects described below are valid for both milling and turning. Read More
  • Stainless Steel SO MAustenitic Stainless Steel is the most commonly used stainless family found in machine shops. It is characterized by high Chromium content, up to 20%, high Nickel amount to 15%, and deficient carbon, usually 0.03%. Due to the high nickel content, It has excellent corrosion resistance. On the(...) Read More
  • Milling Depth of cut
    In milling, the depth of cut is two-dimensional. The Axial depth of cut (AP or ADOC), is the depth of material that the tool removes in its axis direction when it moves perpendicular to it. Read More
  • Nominal Size
    Basic Size (Also may be called nominal size) size is the dimension by which a feature is identified for convenience. It is also the point from which the limits are derived by application of the necessary allowance and tolerances. For example, a slot whose actual width is 25.15 mm would be(...) Read More
  • Hardness measurment device
    One of the most common units used for listing the hardness of steel materials. the test is done with a 10 mm steel ball pressed with 3000 Kgf (6,614 Lbf). Common values for machined materials range from 100 HB for very soft materials up to 650 HB for heat-treated steels. Read More
  • Buit-up edge wear type
    Built-Up Edge (Nicknamed BUE) is a wear mechanism caused by the welding of chips to the insert body. It can occur when machining any raw material but is more common when machining sticky materials, such as low carbon steel, austenitic stainless steel, and aluminum. Read More
  • Tungsten Carbide
    In the machining jargon, the term “Carbide Grade”, or simply “Grade” refers to the combination of sintered tungsten carbide, coating, and other treatments that the cutting indexable insert or solid carbide tool are made off. Each grade is suitable for different materials, cutting conditions(...) Read More
  • Carbon 1
    Carbon is a chemical element designated by the symbol C; moreover, carbon is a critical factor in several machining topics. Although it is added in small doses of 0.03% up to 3% (Usually between 0.1 -1%) to metals, it is the most influential element in many materials used in machine shops. It(...) Read More
  • Plain Carbon Steel
    Carbon steel is the most simple and cheapest form of steel. It is usually defined as steel made of Iron (Fe) with small Carbon (C) addition but without any other alloying elements. Read More
  • Cast Iron ISO K
    Cast Iron (ISO K), is a group of Iron- Carbon-Silicone materials with 1.8-4% of Carbon (C) and 1-3% of Silicon (Si) content. The silicon pushes part of the carbon out of the solution, forming graphite flakes. The material is brittle at room temperature but has a low melting point and thus has(...) Read More
  • CBN Insert
    PCBN (Nicknamed CBN) stands for “Polycrystalline Cubic Boron Nitride”, the second hardest material, second only to diamond. In addition to its high hardness (4,500 HV), it also has excellent hot hardness and chemical stability. Therefore, it can successfully machine Steel up to 70 HRC and(...) Read More
  • Ceramic Insert
    Ceramic Inserts are indexable inserts made from Aluminium Oxide Al2O3 or Silicon Nitride Si3N4. They have a hardness of 2,100-2,500 HV (About 40% above carbide), which enables them to machine Hard Steel up to 55 HRC. It can also machine cast iron and nickel-based alloys six times faster(...) Read More
  • Cermet Insert
    Cermet is a cutting material combining ceramics and metals (usualט Nickel). The result is a harder substrate than carbide, therefore more wear-resistant, and enables machining at higher cutting speeds. The downside is very low toughness, and therefore, it is used only for finishing(...) Read More
  • Load
    Chip load has two meanings: (1) The maximum load that the cutting edge of a specific milling cutter (or indexable insert) can withstand without yielding or having a very short tool-life. (2) The maximum width of the chip that the tooth (or indexable inerts) of a milling cutter cuts out of the(...) Read More
  • Chip Thinning Factor
    When the Radial Depth of Cut [Ae] is smaller than the cutter’s radius, OR the cutter’s shape is not 90° (Chamfer, Ballnose, etc.), The Chip Load is smaller than the Feed per Tooth. This reduction in Chip Load is called “Chip Thinning”. Read More
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