[Glossary] for Machining A-K
Machining is one of the most complex industries. It must have some technical terms that can be confusing. Thats why we organize such A-K glossary. The L-Z part will be shown in the next article. Lets learn the first part now.
Accuracy: A value that is measure by a required method. The accuracy conforms to specific tolerance or standard.
Acute angle: An angle that is less than 90 degrees.
Alloy: A metal with new properties which is formed by the mixture of two or more metals.
Assembly: Parts fitted together to build a new part, complete product, or machine.
Axis: An imaginary line describes the rotation or movement of an object during machining. There are X-axis, Y-axis, and Z-axis in most CNC machines.  
Anodizing: A type of surface finishing which is an oxide layer to protect the object from corrosion.
Angle iron: A piece of metal part in an L-shaped.
ASE: CAD files. A file extension for 3DS Max ASCII export files from autodesk.
Axial hole: A hole that is parallel to the axis of revolution of a turned part, but in no need of concentration.
Blind hole: A hole in the workpiece that can not be pass through it.
Bore: A hole milled through the material.
Brazing: Joining metals by the fusion of nonferrous alloys having a melting temperature above 800 degrees F, but below that of the metal being joined.
Brine: A saltwater solution for quenching or cooling when heat treating the steel.
Brinell hardness: One of the standards of material hardness. A method of testing the hardness of a metal by controlled pressure of a hardened steel ball of a given size.
Buff: Polish the part with cloth or fabric wheel.
Burnishing: A surface finishing, which is the same as polishing for metal by contact with another harder metal for smooth and glossy surface.
Burr: The sharp edges left on the part after machining.
Bushing: A sleeve or liner that will reduce friction and wear inside of a hole.
Bearing: Rollers and balls placed between moving parts to reduce friction and wear.
Bending: The shaping of sheet metal at a predetermined angle. This operation compresses the interior side of the bend and stretches the exterior side.
Caliper: A device to measure the accurate inside and outside dimension.
Center: A point or axis around which anything rotates.
Chipping: The process of cutting metal with a cold chisel and hammer.
Concentric: Accurately centered or having a common center.
Cutting fluid: A liquid used to cool and lubricate the cutting to improve the work surface finish.
CAD: Computer- Aided Design. The software creates 2D and 3D digital models.
CAM: Computer-Aided Manufacturing. A software that can convert the CAD files to program language allows you to create paths for the cutting process on the CNC machines.
Chip size: The size of the metal chips that are created during CNC cutting operations.
CMM: Coordinate measuring machine. A measuring device for shape and dimension of object part to a very high degree of accuracy.
CNC: Computer numeric control. A machining process, which uses computers to control and monitor the movements of a machine tool, via digital instruction derived from CAD/CAM software.
Chamfer: The bevel or angular surface cut on the edge or a corner of a machined part.
Cycle time: The total time it takes to produce one part on a machine.
CNC milling: Uses rotary cutters to remove material.
CNC turning: Uses round bar stock to remove material.
Cutting speed: This measure of speed typically gauges the velocity of the method of cutting travels. A common formula for cutting speed is SFM, which stands for surface feet per minute.
Datum: A reference point on one or more faces, surfaces, or features of a part, from which all other dimensions are calibrated.
DWG: A format of CAD files.
DXF: A format of CAD files.
Deburring: A surface finishing that removes the residues from the upstream machining operation.
Depth of cut: Closely related to speed and feed. Measurement of how much material is being removed along one axis.
Die: A metal block used to form or stamp out metal parts and used to cut external threads.
Die threading: Axial thread-cutting using a multi-edge tool.
Durometer: A measurement of material hardness.
Drilling: A process in machining which uses a rotating drill bit to penetrate the surface of a workpiece and make a round hole.
EDM: Electrical Discharge Machining. A moldmaking method that removes the material by high-powered electrical current(sparks).
Electrode: A sacrificial conductor, usually of copper, which discharges high-powered electrical current to erode the surface of the part.
Eccentric: A circle that does not have a geometric center.
Extrusion: A shaped part resulting from forcing a plastic material such as lead, tin. aluminum. zinc., copper, rubber, and so forth. through a die opening.
Fixture: A custom clamp, vise, or other devices to hold the part steady while machining.
Facing: The process of making a flat or smooth surface in a predetermined set height on the material.
Feed and speed: An act of moving the material relative to the machine cutter. Expressed in inches per minute or per revolution in inches.
Free cut: An additional cut with no advancement of depth.
Finishing pass: A final pass with a very thin cut that enables higher accuracy and better surface finish than a rough cut.
Flutes: It refers to a cutting surface. A 4-flute endmill has 4 cutting surfaces.
Fine blanking: A form of blanking where there is no fracture zone when shearing. This is achieved by compressing the whole part and then an upper and lower punch extracts the blank.  
  • code: A universal numerical control machine tool language that tells the machine what movement to make and speed.
Gauge: A device for measuring or checking the dimensions of the object.
Grinding: Shape or remove materials with a powered wheel.
Hardness: Materials resistance to deformation or scratching by mechanical indentation or abrasion. It measures how difficult it is for the cutting tool to cut materials.
Horizontal machining center: A horizontal machining center is used for milling operations that require a horizontal spindle.
Hex: A term used for anything shaped like a hexagon.
Helix: A path formed as a point advances uniformly around a cylinder, as the thread on a screw or the flutes on a drill.
Heat affected zone: A section of a part whose microstructure and mechanical properties were altered during processing because of heat. Not seen in waterjet cutting, but can occur in laser cutting.
High speed machining: A means of using technology to process materials using higher feed rates and higher RPM to provide a more efficient method of tooling.
IGES: Initial graphics exchange. A common format for exchange CAD data.
Insert: A component that is used to join two objects together.
ISO certification: A certification used to implement quality standards.
ISO 2768: An International standard for tolerance. 2fprototypes conform to the tolerance chart of ISO 2768 strictly.
Jig: Generally used to guide and hold the workpiece, primarily for accuracy and in production machining.
JIT: Also known as "just-in-time" is a term used to describe means used to shorten turnaround time and cut out things that may slow down production.
Knurl: A decorative gripping surface of straight-line or diagonal design made by uniformly serrated rolls called knurls.
Kerf: The width of a cut after being processed.