Cnc glossary 3

anandengg's version from 2018-03-23 04:24


Question Answer
Eccentric– A circle not having a geometric center. Also, a device such as a crankshaft or a cam for converting rotary motion to reciprocating motion.
Element– Matter which cannot be broken up into simpler substances by chemical action, that is, whose molecules are all composed of only one kind of atom.
Elongation– Lengthening or stretching out.
Emery– A natural abrasive used for grinding or polishing. It is being largely replaced by artificial abrasives.
Emulsion– A coolant formed by mixing soluble oils or compounds with water.
Extruded –Metal which had been shaped by forcing through a die.
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
EZY OUT (trademark)– A tool for removing broken bolts or studs from a hole.


Question Answer
Face– To machine a flat surface, as in the end of a shaft in the lathe. The operation is known as facing.
Face Milling– Milling a large flat surface with a milling cutter that operates in a plane that is at right angles to its axis.
Faceplate– A large circular plate with slots and holes for mounting the workpiece to be machined. It is attached to the headstock of a lathe.
Facing– The process of making a flat or smooth surface (usually the end) on a piece of stock or material.
Fatigue– The effect on certain materials, especially metals, undergoing repeated stresses.
Feed – The rate of travel of a cutting tool across or into the work-, expressed in inches per minute or in inches per revolution.
Feed Mechanism– The mechanism, often automatic. which controls the advancing movement (feed) of the cutting tools used in machines.
Female Part– A concave piece of equipment which receives a mating male (convex) part.
Ferrous– A metal alloy in which iron is the major ingredient.
File Test– A test for hardness in which a corner of a file is run across the piece of metal being tested. The hardness is shown by the dent the file makes.
Fillet –A curved surface connecting two surfaces that form an angle.
Fishtail– common name for the center gage. It is used to set thread cutting tools and has scales on it for determining the number of threads per inch.
Fit –The relation between mating or matching parts, that is, the amount of, or lack of. play between them.
Fitting– Any small part used in aircraft construction.
Fixture– A production work-holding device used for machining duplicate workpieces. Although the term is used interchangeably with a jig, a fixture is not designed to guide the cutting tools as the jig does.
Flange –A relatively thin rim around a part.
Flash –A thin edge of metal formed at the parting line of a casting or forging where it is forced out between the edges of the form or die.
Flute –The groove in a cutting tool which provides a cutting edge and a space for the chips to escape and permits the cutting fluids to reach the cutting edges.
Fly Cutter– A single-point cutter mounted on a bar in a fly cutter holder or a fly cutter arbor- used for special applications for which a milling cutter is not available.
Follower Rest– A support for long, slender work turned in the lathe. It is mounted on the carriage, travels close to and with the cutting tool, and keeps the work from springing away.
Footstock– Part of an indexing, attachment which has a center and serves the same purpose as the tail stock of a lathe.
Force Fit– A fitting which one part is forced of pressed into another to form a single unit. There are different classes of force fits depending on standard limits between mating parts.
Forge –To form or shape heated metal by hammering. Also. the name of the unit used for heating metal, as the blacksmith’s forge.
Formed Cutters– Milling cutters which will produce shaped surfaces with a single cut’, and so designed that they may be sharpened without. changing their outline or shape.
Forming Tool –Tool ground to a desired shape to reproduce this shape on the workpiece.
Free Cut –An additional cut with no advancement of depth.
Free Cutting Steel– Bar stock containing a high percentage of sulfur. making it very easy to machine. Also known as Bessemer screw stock.
Free Fit –A class of fit intended for use where accuracy is not essential. or where large temperature variations are likely to be encountered, or both conditions.
Fulcrum –The point or support on which a lever turns.


Question Answer
Gage– Any one of a large variety of devices for measuring or checking the dimensions of objects.
Gage Blocks– Steel blocks machined to extremely accurate dimensions.
Gage, Depth– A tool used in measuring the depth of holes or recesses.
Gage, Drill– A flat steel plate drilled with holes of various sizes, each marked with the correct size or number. into which small twist drills may be fitted to determine the size of their diameters.
Gage, Drill Point – A gage use to check the 59″ angle on drills.
Gage, Feeler (thickness gage) – A gage consisting of a group of very thin blades, each of which is accurately ground to a specific thickness.
Gage, Indicating (dial indicator)– A gage consisting of a dial, commonly graduated (marked) in thousandths of an inch, to which is fastened an adjustable arm.
Gage, Radius (fillet gage)– Any one of a number of small. flat, standard-shaped metal leafs or blades used for checking the accuracy of regular concave and convex surfaces.
Gage, Screw Pitch– A gage consisting of a group of thin blades. used for checking the number of screw threads per unit of distance, usually per inch, on a screw, bolt, nut, pipe, or fitting.
Gage, Surface (scribing block)– A gage used to check the accuracy, of plane surfaces, to scribe lines at desired distances from a given surface and to check the height of a point or points on a piece of work from a given surface.
Gage, Telescoping – A T-shaped gage used to measure the diameter or width of holes.
Gang Milling– A milling setup where a number of cutters are arranged on an arbor so that several surfaces can be machined at one time. It is commonly used for production purposes.
Gear Blank– A stamping, casting. or any, piece of material from which a gear is to be machined. It is usually a disk.
Gib – A tapered strip of metal placed between the bearing surface of two machine parts to ensure a precision fit and provide an adjustment for wear.
Hacksaw– A metal blade of hardened steel having small, close teeth on one edge. It is held under tension in a U-shaped frame.
Half Nut – A lever-operated mechanism that resembles a split nut that can be closed on the lead screw of a lathe when threads are being cut.
Handwheel – Any adjusting or feeding mechanism shaped like a wheel and operated by hand.
Hardening –A heat-treating process for steel which increases its hardness and tensile strength and reduces its ductility.
Hardness Tests– Tests to measure the hardness of metals.
Headstock –The fixed or stationary end of a lathe or similar machine tool.
Heat Treatment –The process of heating and cooling a solid metal or alloy to obtain certain desired properties or characteristics.
Helical Gear –A gear with teeth cut at some angle other than at a right angle across the face of the gear, thus permitting more than one tooth to be engaged at all times and providing a smoother and quieter operation than the spur gear.
Helix –A path formed as a point advances uniformly around a cylinder, as the thread on a screw or the flutes on a drill.
Helix Angle – The angle between the direction of the threads around a screw and a line running at a right angle to the shank.
Hex –A term used for anything shaped like a hexagon.
High-Speed Steel– An alloy steel commonly used for cutting tools because of its ability to remove metal at a much faster rate than carbon steel tools.
Hob– A cylindrical cutting tool shaped like a worm thread and used in industry to cut gears.
Hobbing– The operation of cutting gears with a hob.
Hog –To remove in excess of what is considered normal, sometimes causing accidents or tool breakage; also, to rough out haphazardly.
Hole Saw – A cutting tool used to cut a circular groove into solid material.
Honing –The process of finishing ground surfaces to a high degree of accuracy and smoothness with abrasive blocks applied to the surface under a light controlled pressure. and with a combination of rotary and reciprocating motions.
Hot-Rolled Steel– Steel which is rolled to finished size. while hot. Identified by a dark oxide scale left on the surface.