chapter 19

cermet

A ceramic composite material made out of carbide and sintered oxides, that is used to make disposable tip inserts for cutting tools.

kerf

A cut made in metal or other material by a saw or cutting torch.

grinding

A cutting process that uses abrasive particles to perform the cutting action.

cemented carbide

A cutting tool tip material (tungsten or titanium carbide, suspended in a cobalt matrix) brazed on a tool blank to cut harder material at higher speeds

stick broach

A cutting tool used for pot broaching.

ring broach

A cutting tool, consisting of a series of high-speed steel rings, that is used for pot broaching.

lasing tube

A cylinder filled with gas, such as CO2 or argon, that is energized by an electric current and releases energy in the form of coherent light. The output of the tube is focused into a beam to do work.

faceplate

A disk fixed with its dace at a right angle to the live spindle of a lathe for the attachment of the work.

reaming

A final finishing process that improves the dimensional accuracy and surface finish of a drilled hole.

internal cylindrical grinding

A form of grinding that is done when the surface of a hole must be accurately smoothed. A tool post grinder attached to a lathe or a specialty grinding machine is used.

external cylindrical grinding

A form of grinding that uses a grinding wheel which runs over the outside surface of a work piece. The work is secured between centers or in a chuck.

surface grinding

A form of precision grinding done on flat work pieces.

gang cutting

A form of traveling wire electrodischarge machining that uses multiple heads to simultaneously cut single or multiple workpieces.

abrasive jet machining

A grinding process that suspends tiny particles of abrasive material in a low pressure steam of gas (dry air, carbon dioxide, or nitrogen) sprayed through a sapphire nozzle.

rotary shearing

A hand process that is similar to straight shearing, except that the cutting blades are rotary wheels used to cut either straight or circular shapes

photoresist

A light-sensitive coating that is applied to a substrate, then exposed and developed to provide a mask during chemical etching .

slotter

A machine tool used for making a mortise or shaping the slides of an aperture.

milling

A machining process that uses a multi toothed cutter to produce slots, grooves, contoured surfaces, threads, spirals, and many other configurations. Also, a grinding process in which hard clay is broken down into fine particles by passing through a series of rollers.

shearing

A mechanical separating process often used to cut flat stock from sheet or plate.

electrochemical machining (ECM)

A method of material removal that shapes a work piece by removing electrons from its surface atoms. In effect, ECM is the opposite of electroplating.

contouring

A method used to remove metal from surfaces of irregularly shaped parts by selectively etching to the desired depth.

lasing medium

A mixture of carbon dioxide and nitrogen used in a laser.

cathode

A negative electrode.

planing

A operation that is used to remove large amounts of material from horizontal, vertical, or angular flat surfaces.

anode

A positively charged electrode.

climb milling

A process in which the cutter is positioned on top of the work piece, with the work moving in the same direction as the cutter's rotation

up milling

A process in which the cutter is positioned on top of the work piece, with the work piece fed in the direction opposite the rotation of the cutter.

punching

A process similar to blanking, except that material stamped out of the sheet metal is usually scrap.

ultrasonic machining

A process that removes material by erosion, using vibrations generated by high-frequency sound waves.

contour machining

A process that selectively etches a desired area to some specified depth.

waterjet machining

A process that uses a high-velocity stream of water to cut materials ranging from paper to stone or metals.

nibbling

A process that uses a small round or triangular punch to rapidly take small round or triangular punch to rapidly take small "bites" out of sheet metal, allowing the cutting out of limited numbers of flat parts with complex shapes.

electrodischarge machining (EDM)

A process that uses electrical energy in the form of sparks to erode stock from a metal work piece.

rough grinding

A process used for rapid material removal on castings, forging, and welded parts.

gun drilling

A process used to drill deep, accurate holes. It was originally used to drill gun barrels.

blanking

A process used to punch a flat blank from sheet metal. Blanking produces very little waste.

punch-and-die shearing

A production shearing process using a shaped punch and matching die.

perforating

A punching process that produces closely and regularly-spaced holes in a straight line across sheet metal, usually to facilitate bending.

lancing

A punching process used to make a tab without removing any material.

tap

A shanked tool with rows of cutting teeth, separated by flutes, that are used to cut threads inside a hole.

collet

A socket, equipped with threads pm one end and split jaws on the other, which is used in a lathe to automatically center stock that is round, square, octagonal, or hexagonal.

centerless grinding

A special type of cylindrical grinding that can be used for external or internal applications.

fixture

A special work holding device.

pull broach

A tapered cutting tool used to shape holes in work piece.

electro beam machining (EBM)

A thermoelectric process that focuses on high-speed beam of electrons on the work piece.

universal chuck

A three-jawed device used to hold a work piece in the head stock of a lathe. The three jaws make it self-centering.

slab broach

A tool with cutting teeth on its flat face, used to shape the outside of a work piece.

pot boraching

A type of broaching used to economical produce items such as precision external spur gears and automotive front-wheel-drive transmission gears.

shell broach

A type of internal cutting tool that is often used to cut helical splines, such as the rifling used inside gun barrels.

bed-type machine

A type of milling machine in which a worktable is mounted directly on the machine bed.

column-and-knee-type machine

A type of milling machine in which a worktable is mounted on a knee that moves up and down the column

vertical milling machine

A type of milling machine in which the cutter is positioned perpendicularly to the worktable.

maskant

A type of resist that is not photo-sensitive. It is applied to a surface, then mechanically removed from areas that are to be etched.

traveling wire EDM

A type pf EDM in which the cutting is done by using a round wire that travels through the work piece.

slitting

A variation of shearing that creates a slit in metal where another part or device can be inserted.

laser

An active electron device that converts input power into a very narrow, intense beam of coherent visible or infrared light; used for cutting, drilling, welding, heat treating, soldering and wire stripping.

chemical blanking

An etching process that forms a part by etching completely through the workpiece.

flutes

Channels on a drill bit though which chips are carried out of the hole being drilled.

broach

Cutting tool that creates a planing action when pushed or pulled across or through a work piece.

ring-and-stick broach

Cutting tools that are used to broach teeth on gear blanks at the same time that other operations are being performed.

ions

Electrons that have been drawn free of their atoms in the electrochemical machining or electroplating processes.

post process

Generates the program for the machine tool.

cylindrical grinding

Grinding process used on work pieces with curves surfaces or cylindrical shapes.

blind holes

Holes that do not run through the work piece

arbor

In a machine tool, the rotating spindle on which a cutting tool is mounted.

turning center

Machine in which a stationary cutting edge is placed against a rotating bar of metal to reduce the diameter of the bar.

precision grinding

Process often used on materials that are too hard to cut with conventional tools.

tapping

Process that is used to cut threads inside a hole.

chemical milling

Process used to each or form metallic parts.

turning processes

Processes that are used to machine rotating parts.

straight shearing

The action of cutting sheet metal to size in rectangular pieces

etchants

The agent that is used to etch (chemically machine) metals, glass, or other materials.

depth of cut

The amount of material being removed from the work piece in a single pass of the cutting tool.

plating

The deposition of metal on a cathode.

feed

The distance a cutting tool travels in one minute.

collimated

The focused, parallel light rays of a laser beam.

thermal energy

The high-velocity stream of electrons that is generated by the electron beam gun.

tip angle

The included angle formed when measuring from one side of the tip of a drill to the other.

drop

The material separated from a part.

swing

The maximum diameter of a work piece that can be turned on a lathe.

twist drill

The most come type of drill for metals, normally made of high-speed steel or carbon steel.

lathe

The most common machine used to perform machining operations on round parts.

shear line

The path that the shearing follows.

nesting

The positioning of blanks so that multiple parts can be cut from one work piece with a minimum amount of waste.

speed

The revolution per minute (rpm) that the work piece or cutting tool is turning.

resonance point

The specific frequency at which an ultrasonic cutting tool must vibrate to be effective.

end effector

The tool or device mounted on the end of the arm of an industrial robot

notching

This process, which is similar to nibbling is typically done using a punch press.

horizontal milling machine

This type of milling machine has the cutting tool carried on an arbor or spindle that travels along as axis parallel to the worktable.

internal threads

Threads that are on the inside of a hole.

rake angle

the angle on the end of each row of teeth of a tap. Wider flutes at the bottom of the tap help to remove chips when the tap is backed out of the hole.