Thermal Cutting Overview 281

2D

Two-dimensional. Occurring only in the axes of length and width. 2D cutting operations are often performed by gas lasers.

3D

Three-dimensional. Occurring in more than two axes of movement. 3D cutting operations are often performed by solid-state lasers that are delivered by an optical fiber.

AC

Alternating current. An electrical current that reverses direction at regularly recurring intervals of time. AC is more easily converted to higher and lower voltages.

AC coated electrodes

One of three specialized types of carbon electrodes used in air carbon arc cutting. AC coated electrodes have materials added to them that stabilize the arc produced when cutting with AC.

acetone

C3H6O. A liquid used in acetylene cylinders to dissolve and store acetylene. Acetone allows for safer storage of acetylene.

acetylene

C2H2. A colorless, flammable gas that is the most common fuel gas used in oxyfuel welding. Acetylene should not be used at pressures above 15 psi (103.42 kPa) and becomes highly unstable at higher pressures.

air carbon arc cutting

CAC-A. A method of thermal cutting that uses the intense heat from a carbon arc to melt a metal workpiece. Air carbon arc cutting uses compressed air to remove the molten metal from the cut.

air compressor

A device that increases air pressure by moving air into a closed system. An air compressor is used in air carbon arc cutting to pressurize ambient air and direct it into the torch.

air hose

A type of air conductor that joins other components together. Air hoses bend and flex and are often quite versatile.

air valve

A mechanical device that regulates the flow of air with moveable parts that open, close, or obstruct one or more openings or passageways. Air valves direct air movement and regulate the amount of pressure.

air-cooled

A type of torch that is designed to operate at its rated amperages without requiring a water-cooling system. Air-cooled torches are intended for lower duty cycle applications.

argon

A colorless, odorless type of inert gas. Argon is sometimes used as plasma gas in plasma cutting.

assist gas

A gas used during the laser cutting process that removes molten metal from a cut and improves cut quality and cutting performance. Assist gases include oxygen, nitrogen, and compressed air.

atoms

The smallest distinguishable unit of a material. Atoms maintain the same characteristics of that material.

automated

A system or process that does not require human intervention. Automated systems include CNC machines and robotics.

backflow

An unwanted movement of gas in the reverse direction. Backflow of oxyfuel gases can be prevented by check valves.

beam optics

Special types of lenses in a laser cutting machine that focus the laser beam to a pinpoint. The type and number of beam optics vary based upon the distance between the cutting nozzle and the workpiece.

bevel angle

The angle formed between the prepared edge of one side of the base metal and a plane perpendicular to the surface of the other side of the base metal. Bevel angle cut location on the workpiece is determined by the gas distributor in a plasma cutting torch.

British thermal units

BTU. The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit (F). British thermal units are the standard English unit of measurement that is used to determine the amount of heat energy in fuels.

BTU

British thermal units. The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit (F). BTU is the standard English unit of measurement that is used to determine the amount of heat energy in fuels.

BTU/ft.³

British thermal units per cubic foot. An English unit of measurement that is used to determine the amount of heat energy in fuels. BTU/ft.³ measures the amount of heat contained in one cubic foot.

CAC-A

Air carbon arc cutting. A method of thermal cutting that uses the intense heat from a carbon arc to melt a metal workpiece. Air carbon arc cutting uses compressed air to remove the molten metal from the cut.

carbon

A non-metallic chemical element which increases hardness in metal. Carbon is combined with graphite to create the carbon electrodes used in air carbon arc cutting.

carbon

C. A common, strong, nonmetallic element. Carbon can combine with hydrogen to create a variety of different hydrocarbon gases.

carbon dioxide

CO2. A colorless and odorless naturally occurring gas. Carbon dioxide is electrically and thermally conductive.

carbon dioxide lasers

CO2 lasers. A type of gas laser that uses a helium, nitrogen, and carbon dioxide gas mixture as a lasing medium. Carbon dioxide lasers are highly efficient and operate as a continuous wave laser.

carbon electrode

An electrode used for air carbon arc cutting. Carbon electrodes are made from a mixture of carbon and graphite, and some are coated with copper.

CC

Constant current. A power supply that maintains a steady flow of current, regardless of fluctuation in voltage. Almost all plasma cutting machines operate on constant current power supplies which create stable arcs.

check valves

A part of the oxyfuel outfit installed between the hose and the torch. Check valves prevent the unintentional backflow of gases.

chemical reaction

A process in which one or more substances are changed into another substance. Chemical reactions change the physical structure of a substance in some way.

circuit

A completely enclosed path that contains an electrical current. In arc welding and thermal arc cutting methods, a circuit is also known as a welding circuit.

CNC machine

Computer numerical control machine. A machine controlled by a computer that runs special programs to manufacture a workpiece. CNC machines are very rigid and are capable of fast cutting speeds.

CO2 lasers

Carbon dioxide lasers. A type of gas laser that uses a helium, nitrogen, and carbon dioxide gas mixture as a lasing medium. CO2 lasers are highly efficient and operate as a continuous wave lasers.

coherent

In light waves, moving in unison with one another. Coherent light is emitted at the same rate and with the same frequency.

collimated

In light waves, to be aligned parallel. Collimated light does not diverge, or minimally diverges, with distance.

combust

To ignite or catch fire and burn. Materials combust when heated to their kindling temperature.

combustible

Capable of catching fire and burning. Combustible materials must never be present in a thermal cutting or welding area.

combustion

The process of igniting, or catching fire, and burning. Combustion is usually a chemical reaction that produces heat and light.

compressed air

Air that has been pressurized. Compressed air is usually squeezed into a small space, such as a tank.

compressed gas

Any gas held under pressure in a gas cylinder. Compressed gases, such as nitrogen, argon, and oxygen, are sometimes used in plasma cutting.

computer numerical control

CNC. A type of programmable control system, directed by mathematical data, which uses microcomputers to carry out various machining operations. CNC control systems can be used in automated laser cutting applications.

computer numerical control machine

CNC machine. A sophisticated machine run by a computer that can perform multiple machining operations in the same setup with a variety of tools. Computer numerical control machines require variables, such as travel direction and speed, to be programmed and input by an operator.

constant current

CC. Welding or cutting processes using a current that varies slightly with changes in voltage. Constant current is often used in shielded metal arc welding (SMAW) and air carbon arc cutting (CAC-A).

constant voltage

CV. Welding or cutting processes using a voltage that varies slightly with significant changes in current. Constant voltage is used in several arc welding processes.

consumables

Any material that is used up or wears out over time. Consumables for welding and cutting include electrodes, fluxes, and nozzles.

consumables

Any part of a plasma cutting machine that may wear over time or through usage. Electrodes, nozzles, and gas distributors are the main consumables, though some torches have others.

contamination

The presence of damaging foreign or atmospheric materials such as dirt, moisture, or oil. Contamination can damage electrodes and compromise cut quality.

continuous wave

CW. A laser beam that is produced continuously rather than as a series of pulses. Continuous wave lasers provide a constant output power.

cross-ventilation

A type of building ventilation that occurs naturally. Cross-ventilation requires air to be able to flow from an entrance to an exit without barrier.

crystalline

A solid structure with atoms arranged in a highly organized and repeating structure. Crystalline materials, such as yttrium aluminum garnet (YAG), are used as a laser source.

current output

The type of current that the welding power source produces. Current outputs include direct current (DC) and alternating current (AC).

cutting jet

A concentrated, high-powered stream of pure oxygen. The cutting jet is used to pierce and cut metal during the oxyfuel cutting process.

cutting jet trigger

A lever on an oxyfuel cutting torch. Cutting jet triggers control the release of the high-powered, concentrated stream of oxygen that begins the cutting process.

cutting nozzle

The component that directs and aligns the assist gas with the laser beam in laser beam cutting. Cutting nozzles must be carefully chosen to avoid any errors during the cutting process.

cutting outfit

The basic equipment and setup used during the oxyfuel cutting process. Cutting outfits are also referred to as cutting rigs.

cutting rig

The basic equipment and setup used during the oxyfuel cutting process. Cutting rigs are also referred to as cutting outfits.

cutting table

The surface on which the workpiece rests during an automated cutting process. The cutting table supports the workpiece and catches sparks or slag produced while cutting.

cutting tip

A replaceable nozzle for a gas torch that is especially adapted for oxyfuel cutting instead of welding. Cutting tips are made in a variety of sizes and orifice configurations based upon the type fuel gas used and the depth of cut required.

cutting torch

A tool used to control the severing of a workpiece during thermal cutting processes. Cutting torches are specialized to the type of thermal cutting process in which they are used.

cylinder cap

A device used to protect the valve mechanisms of a cylinder from physical damage while cylinders are in storage or transport. Cylinder caps must be kept on the gas cylinders when the cylinders are not secured.

cylinder truck

A two-wheeled dolly used to safely secure gas cylinders while in use. Cylinder trucks can also be used to safely transport gas cylinders between work locations.

cylinder valve

A device used to prevent the flow of gas from a cylinder while not in use. Each cylinder valve uses a connection that has been approved by the Compressed Gas Association for each specific gas.

darkness rating

The amount of shading provided by filter plates. Darkness ratings range from 1, which offers the least protection, to 14, which offers the greatest protection.

DC

Direct current. An electrical current formed when electrons flow in one continuous direction. All plasma cutters operate using DC current.

DC copper-coated electrodes

One of three specialized types of carbon electrodes used in air carbon arc cutting. DC copper-coated electrodes have a relatively long electrode life, stable arc, and low electrical resistance.

DC plain electrodes

One of three specialized types of carbon electrodes used in air carbon arc cutting. DC plain electrodes are not coated with copper and must be replaced more frequently than other electrodes used for air carbon arc cutting.

decompose

To separate or break down into smaller, individual components. At high pressures, acetylene can decompose and become highly explosive.

diameter

A measurement of the thickness of the electrode. The diameter of an electrode can affect productivity.

direct current

DC. Current that flows in one continuous direction. Direct current is required in several common welding and cutting processes such as carbon air arc cutting (CAC-A) and gas metal arc welding (GMAW).

direct current electrode negative

DCEN. The arrangement of direct current cables and leads in which the electrode is the negative pole and the workpiece is the positive pole of the electric arc. With direct current electrode negative polarity, electricity flows from the electrode to the workpiece.

direct current electrode positive

DCEP. The arrangement of direct current welding or cutting cables and leads in which the electrode is the positive pole and the workpiece is the negative pole of the arc. With direct current electrode positive, electricity flows from the workpiece to the electrode.

direct-diode lasers

A type of high-powered semiconductor laser. Direct-diode lasers produce enough power for use in some thermal cutting operations.

directional

In light waves, moving toward a particular location. Directional light is emitted as a relatively narrow beam in one specific direction.

distortion

Warpage or disfigurement in the base metal. Distortion occurs due to stresses caused by heating base metal to expansion and then cooling it to contraction.

doping agent

An element that, when added in trace amounts to a substance, changes the electrical properties of the substance. Doping agents are also called dopants.

drag shield

A component that mounts on the front of a handheld plasma torch in order to prevent it from getting too close to the workpiece. Drag shields are also known as shield cups.

duty cycle

The amount of time in a ten-minute period that an electrical device can perform work without overheating. If a device has a 30% duty cycle, it can operate for three consecutive minutes and must rest for seven.

earmuffs

Ear wear that protects hearing as well as the outer ear from flying sparks or debris. Earmuffs consist of two ear coverings connected by a band.

earplugs

A protective device that is inserted in the ear to block noise. Earplugs can be made from wax, cotton, foam, silicone, or rubber.

electric arc

The area in which electricity jumps from an electrode to another conductor to produce extreme heat and light. Electric arcs are used in thermal cutting, welding, and in some types of industrial furnaces.

electrical pumping

The use of an externally supplied electrical current to excite and amplify the energy of the lasing medium for gas lasers. Electrical pumping can use radio frequencies, direct current, or alternating current.

electrical resistance

The force that opposes the flow of electrical current. Electrical resistance also affects voltage.

electrical shock

The flow of electricity that occurs when a part of the human body contacts a source of electricity. Electrical shock is dangerous, and, depending on the level of exposure, it can be fatal.

electrically conductive

The ability of a material to act as a medium for conveying electricity. Ionized matter is electrically conductive.

electrode extension

The distance from the end of the contact tip to the end of the electrode. Electrode extension can also be called electrical stickout.

electrode head

The part of the air carbon arc torch that holds the electrode. The electrode head contains holes that direct the flow of compressed air to the workpiece and pivots to align the airflow with the electrode.

electrode holder

The insulated handle that clamps onto the electrode. The welder holds the electrode holder during shielded metal arc welding (SMAW) to control the arc.

electrode lead

An electric wire that connects a power source to an electrode. The electrode lead is most frequently attached to a power source's positive terminal when performing air carbon arc cutting.

electrons

The smallest part of the atom that revolves around the positively charged nucleus. Electrons have a negative charge, and they are the basic source of electricity.

excites

Absorbs and possesses additional energy on an atomic level. Excited atoms release the extra energy as light.

face shield

A rigid, transparent plastic sheet that covers a welder's entire face to protect against molten metal, slag, and spatter. Because face shields do not protect against impacts, they are often worn with goggles.

filter plates

The shaded protective lens inside the welding helmet that filters out harmful rays and intense bright light. Filter plates' required amount of shading depends on the welding or cutting process, the materials used, and the power source.

fire extinguisher

A portable device that uses a rapid spray of chemicals to put out small fires. Fire extinguishers are an essential part of fire prevention.

fire-resistant

FR. Made of materials which are designed to resist burning and withstand heat. Fire-resistant materials for PPE are rated and must meet specific safety standards.

fixed optic systems

A laser cutting machine configuration that moves a workpiece under a stationary laser beam. Fixed optic systems are generally slower than other laser cutting systems and have a simple beam delivery system.

flame cutting

A thermal cutting process that uses a flame produced by oxygen and fuel gas along with a high pressure stream of oxygen. Flame cutting, which is sometimes called oxyfuel cutting (OFC) or gas cutting, is a very convenient and cost-effective cutting process.

flame speed

The rate at with a flame expands outwards from a combustion reaction. Flame speed is typically measured in feet per second (ft./sec) or meters per second (m/sec).

flammable

Able to quickly catch fire under normal circumstances with the help of a minimal ignition source such as a single spark. Flammable materials must never be present in a thermal cutting or welding area.

flash lamps

A tube that is designed to produce extremely intense light for short durations of time. Flash lamps are often used in the optical pumping process for solid-state lasers.

flashback

A torch malfunction in which the flame briefly or continually moves up into the torch and hoses. Flashbacks can cause equipment damage or personal injury if not prevented or controlled.

flashback arrestors

A part of the oxyfuel outfit installed between the hose and the torch. Flashback arrestors prevent flashback from reaching into the hoses and causing an explosion.

flow rate

A variable that describes the movement of a substance from one place to another in a specific amount of time. Flow rate is usually measured in standard cubic feet per hour (SCFH) or in liters per minute (l/min).

flow rate

The rate at which a gas moves from its cylinder or container, through a gas delivery system, and to the arc and molten metal. Flow rate is usually measured in standard cubic feet per hour (SCFH) or in liters per minute (l/min).

flying optics systems

A laser cutting machine configuration that uses a gantry robot to move a laser beam over and around a stationary workpiece. Flying optics systems are very fast and precise, highly versatile in the type and shape of parts they are able to successfully cut, and their cutting process is highly repeatable.

focal point

The point at which rays or waves meet after reflection or refraction. Focal points, or focal spots, are often created by one or a series of lenses.

focus head

One or more lenses or mirrors aligned within a mechanical assembly that are used to concentrate a laser beam. Focus heads, which are sometimes called focusing devices, concentrate a laser beam to a focal point.

focus head assembly

The focus head as well as the components it controls. Focus head assemblies include the beam optics and cutting nozzle.

focusing device

One or more lenses or mirrors aligned within a mechanical assembly that are used to concentrate a laser beam. Focusing devices, which are sometimes called focus heads, concentrate a laser beam to a focal point.

fuel gas

One of a variety of gases with the ability to store potential energy released as thermal energy or that can be used to perform work. Fuel gases include methane, propane, acetylene, and natural gas.

fume extractor

Any device that uses suction to remove from the environment the smoke and gases generated during welding and cutting processes. Fume extractors are sometimes called welding hoods.

fume plume

A cloud-like area where welding fumes collect. Fume plumes can be hazardous to a welder's health and safety.

fumes

Potentially hazardous gases and particulate matter generated at the electric arc during welding or cutting processes. Fumes include particulates from the electrode, flux, shielding gas, base metal, and any coatings included in a process.

gantry

The mechanized bridge upon which tooling is mounted. A gantry's movement is controlled by a CNC machine.

gas cutting

A thermal cutting process that uses a flame produced by oxygen and fuel gas along with a high pressure stream of oxygen. Gas cutting, which is sometimes called oxyfuel cutting (OFC) or flame cutting, is a very convenient and cost-effective cutting process.

gas cylinders

Metal containers used to store gases. Gas cylinders are built specifically for each gas and have different properties depending on the type of gas.

gas distributor

The device that swirls plasma gas to keep it centered on the electrode and the nozzle opening. Gas distributors are also known as swirl rings.

gas flow control

The regulation of gas or air flowing to the torch. Gas flow control is achieved with a flow control valve.

gas hoses

A type of gas conductor that is flexible and often quite versatile. Gas hoses connect oxyfuel cylinders to the torch in oxyfuel cutting.

gas lasers

A device that produces a laser beam by discharging electrical current though a gas medium. Gas lasers include carbon dioxide lasers, helium-neon lasers, and argon-ion lasers.

gas regulators

The device used to control the amount of gas that flows from a cylinder. Gas regulators consist of a valve to control pressure and a gauge to measure the pressure flowing through them.

gauntlets

A type of protective glove that extends past the end of the shirt sleeves to cover the arm. Gauntlets provide an additional level of protection when performing welding or cutting processes.

gouging

Removing metal, an old weld, or any imperfections in a workpiece. Gouging can be performed with a variety of methods, including air-carbon arc and plasma.

graphite

A black, soft form of carbon that conducts electricity and is easily machined. Graphite is combined with carbon to create the carbon electrodes used in air carbon arc cutting.

hafnium

Metal used as an electron emitter in plasma cutting. Hafnium inserts are usually placed inside copper plasma cutting tips.

HAZ

Heat-affected zone. The portion of the base metal that is immediately adjacent to the cut or weld and has not been melted. HAZs have mechanical properties that have been altered by the heat of thermal cutting or welding.

heat-affected zone

HAZ. The portion of the base metal that is immediately adjacent to the cut or weld and has not been melted. Heat-affected zones have mechanical properties that have been altered by the heat of thermal cutting or welding.

helium

He. A light, colorless, type of inert gas. Helium is nonflammable.

high-frequency contact starters

A device in a plasma cutting machine that ignites the plasma arc through the use of high voltage circuits. High frequency contact starters can cause interference with other electronic devices and are usually only found in older plasma cutting systems.

hose connectors

The part of an oxyfuel torch where the flashback arrestor is attached to the torch. Hose connectors are made of brass to ensure safety and durability.

hybrid systems

A laser cutting machine configuration that moves both the workpiece and laser beam. Hybrid systems typically move the workpiece along one axis and the cutting nozzle along another axis.

hydrocarbon

A type of chemical compound containing only hydrogen (H) and carbon (C). Hydrocarbons are predominantly used as a source of combustible fuel.

hydrogen

H. A colorless, odorless gas, and the most abundant element on the planet. Hydrogen can combine with carbon to create a variety of different hydrocarbon gases.

ignition temperature

The lowest temperature at which a substance or material, when heated, spontaneously catches fire and continues to burn. Ignition temperature is also called kindling temperature.

industrial robots

A reprogrammable, multifunctional device that uses highly adaptable programmed motions to perform various processes.. Industrial robots are a form of automation.

infrared light

IR. Invisible rays emitted during many welding and cutting processes. Infrared light can damage vision.

inner cone

The bluish-white, clearly defined, and easily visible cone shape at the center of an oxyfuel flame. The inner cone is located closest to the cutting torch tip and frequently produces the most heat.

inside diameter

The interior surface of a spherical or cylindrical object. The inside diameter for the air hose used in air carbon arc cutting must be no less than 0.38 in. (6.40 mm) in order to avoid restricting airflow.

ionizes

To negatively or positively charge an atom or collection of atoms by adding or removing one or more electrons. Ionized gases are called plasmas, and are positively charged when used in plasma cutting.

iron

A silver-white, metallic element that is the fourth most abundant element on earth. Iron undergoes a chemical reaction when exposed to oxygen and forms iron oxides.

iron oxide

A metallic compound containing iron and oxygen. Iron oxides, such as rust and slag, are formed by a chemical reaction between iron and oxygen.

kerf

A cut or opening created in a workpiece during a thermal cutting operation. Kerf sometimes refers to the width of a cut or the width of the material removed by a cutting process.

keyhole

A cavity formed in the surface of a workpiece. Keyholes form when a material is heated up to its vaporization temperature.

kilopascals

kPa. A unit of pressure derived from the International System of Units (SI). A kilopascal is equal to 1,000 pascals (Pa).

kindling temperature

The lowest temperature at which a substance or material, when heated, spontaneously catches fire and continues to burn. Kindling temperature is also called ignition temperature.

kPa

Kilopascals. A unit of pressure used in the SI system. The unit kPa measures the amount of load pressure that is applied over one square meter.

laser

A device that generates a coherent, collimated, single wavelength of light that can be precisely aimed and controlled. Lasers are used for cutting and welding applications as well as other thermal processing.

laser beam

An intense beam of coherent, collimated, monochromatic light that can be precisely aimed and controlled. When combined with a focus head, laser beams can be used for cutting, welding, and other thermal processes.

laser beam cutting

LBC. A thermal cutting process that uses a focused beam of coherent, collimated, monochromatic light to sever a workpiece. Laser beam cutting is usually an automated process that produces intricate and repeatable cuts.

laser beam cutting

LBC. A thermal cutting process that uses a focused stream of coherent, collimated, monochromatic light to sever a workpiece. Laser beam cutting is usually an automated process that produces intricate, continuous cuts.

laser cutting machine

A device that generates, focuses, concentrates, and delivers a laser beam to a workpiece. Laser cutting machines include a cutting nozzle and cutting optics.

laser disk

A very thin circular-shaped material that acts as a lasing medium and is embedded with a doping agent. Laser disks are used in solid-state lasers.

laser rod

A solid round or rectangular bar-shaped material that acts as a lasing medium and is embedded with a doping agent. Laser rods are used in solid-state lasers.

lasing medium

A liquid, gas, solid, or semi-conductor that produces a wavelength of light when it is exposed to and absorbs energy. Different lasing mediums produce different wavelengths of light.

machining

The process of removing metal to form or finish a part using a cutting or abrasive tool. Traditional machining methods, such as milling, turning, and drilling, remove metal using cutting tools.

manual

A process that requires an operator to entirely perform the process and control the variables. Manual thermal cutting processes require an operator to perform the cut as well as control all cutting variables, such as the torch position, travel direction, and speed.

mechanical cutting

A process that uses an electrically powered machine or tool to remove metal from a workpiece. Mechanical cutting methods include machining, shearing, sawing, and grinding.

mechanical ventilation

The process of providing an area with a constant source of fresh air using machines. Mechanical ventilation may include the use of fume extractors or respirators.

mechanized

A type of process in which the primary operation is performed and controlled by a machine. Mechanized processes often require an operator to input computer code as well as supervise while the mechanized process is carried out.

megajoules

MJ. One million joules (j). Megajoules are a metric unit of measurement that is used to determine the amount of heat energy in fuels.

methane

CH4. A colorless, flammable gas that is the most common natural gas. Methane is sometimes used as a fuel gas in the oxyfuel cutting process.

microstructure

The shape and alignment of the microscopic components of a metal. Microstructure is key in determining hardness, toughness, and other variables.

mixing chamber

A part of an oxyfuel torch that is either located in the torch head or body or in part of the tip. Mixing chambers are where the oxygen and fuel gas combine just prior to being burned by the flame.

MJ/m³

Megajoule per cubic meter. A metric unit of measurement that is used to determine the amount of heat energy in fuels. MJ/m³ measures the amount of heat contained in one cubic foot.

monochromatic

Consisting of only one wavelength, or color. Monochromatic light can be amplified into a powerful laser beam.

multiple-axis coordinate system

A numerical system used to describe the location of an object in three-dimensional space. Multiple-axis coordinate systems express the distance from any point to the fixed intersection of three or more liner axes.

natural gas

A flammable, naturally occurring gas that consists mainly of methane and other hydrocarbons. Natural gas is sometimes used as a fuel gas in the oxyfuel cutting process.

natural ventilation

The process of providing an area with a constant source of fresh air using the natural movement of the outside air. Areas using natural ventilation require at least 10,000 cubic feet (283.17 cubic meters) of area per welder.

needle valves

The part of the torch used to regulate the amount of oxygen and fuel gas flowing into the torch. Needle valves consist of a sharp conical obstruction that is extended or retracted to block or allow gas flow.

negative terminal

A connecting point in a circuit that has a negative charge. Negative terminals and positive terminals are attached to wires, which creates an electrical connection.

negatively charged

Having an electric charge with a surplus of electrons. A negatively charged material is often symbolized by a minus (-) sign.

nickel

A hard, malleable, silvery white metal. Nickel is often used in various alloys to add strength, toughness, and impact resistance to metals.

nitrogen

A colorless, odorless, tasteless gas that naturally makes up 78% of breathable air. Nitrogen is sometimes used as plasma gas in plasma cutting.

nitrogen

N. A colorless, odorless, tasteless, naturally occuring gas. Nitrogen exists in the atmosphere and makes up 78% of breathable air.

nonferrous metals

A metal that does not contain iron as a main ingredient. Common nonferrous metals include aluminum, titanium, copper, and nickel.

nozzle

A component at the tip of a plasma cutting torch that directs plasma into a narrow jet directed at the workpiece. Nozzles, which are also called torch tips, are one of the main consumables in a plasma torch.

nuclei

The central portion of an atom. The nuclei hold protons and neutrons, while electrons orbit around the nuclei.

Occupational Safety and Health Administration

OSHA. The federal agency that sets the standards for working conditions in the United States and ensures that employees work in safe and healthy environments. The Occupational Safety and Health Administration also enforces workplace health and safety regulations.

optical energy

Energy in the form of light. Optical energy is converted into thermal energy during laser beam cutting.

optical fibers

A filament made of thin, flexible silica or plastic capable of transmitting light. Optical fibers are sometimes used in solid-state lasers.

optical pumping

The use of an externally supplied light to excite and amplify the energy of the lasing medium in a solid-state laser. Optical pumping can use a variety of light sources including flash lamps, arc lamps, and laser diodes.

optical resonator

A device consisting of a laser cavity, lasing medium, lasing rod, and two reflecting mirrors. The optical resonator's mirrors reflect light and amplify it into a powerful laser beam.

orifice

The hole or holes at the end of a torch tip. The shape and number of holes determine the use of the tip.

outer cone

The light blue envelope, which is less-defined and often produces significantly less heat, surrounding the inner cone of an oxyfuel flame. The outer cone changes shape depending on the fuel gas used and the gas ratio.

oxidation

A material's chemical reaction with oxygen. Oxidation usually involves the addition of oxygen, the removal of hydrogen, or the removal of electrons from an element or compound.

oxidizes

To chemically combine and react with oxygen. In oxyfuel cutting, a stream of pure oxygen oxides the iron in preheated ferrous metals.

oxyacetylene cutting

A mix of oxygen and acetylene that is used to fuel a flame for cutting metal. Oxyacetylene produces a flame with a higher temperature than all other oxyfuel cutting processes.

oxyfuel cutting

OFC. A thermal cutting process that uses a flame produced by a mixture of oxygen and fuel gas along with a high pressure stream of oxygen. Oxyfuel cutting, which is sometimes called flame cutting or gas cutting, is a very convenient and cost-effective cutting process.

oxyfuel cutting

OFC. A thermal cutting process that uses a flame produced by oxygen and fuel gas along with a high pressure stream of oxygen. Oxyfuel cutting, which is sometimes called flame cutting or gas cutting, is a very convenient and cost-effective cutting process.

oxyfuel cutting torch

A tool used to control the fuel and oxygen used to create a flame for preheating and to introduce the oxygen used for cutting. Several different oxyfuel cutting torch types are available to use.

oxygen

A colorless, tasteless, odorless gas that is roughly 20% of Earth's atmosphere. Oxygen is sometimes used as plasma gas in plasma cutting.

oxypropylene

A mix of oxygen and propylene that is used to fuel a flame for cutting metal. Oxypropylene creates a flame in which the flame's outer cone produces a higher BTU than its inner cone.

part program

Instructions used by a CNC machine to perform the necessary sequence of operations to machine a specific workpiece. Part programs are usually composed of a series of letters, numbers, and symbols.

personal protective equipment

PPE. Various safeguarding devices that workers use to prevent injury in the workplace. Personal protective equipment includes safety glasses, gloves, masks, and earplugs.

photon

A particle of light energy. Photons are released in semiconductor lasers.

pilot arc

An electrical current that flows between the electrode and the nozzle. Pilot arcs become cutting arcs once the current begins to flow from the electrode to the workpiece.

pilot arc contact

A part in a plasma cutting torch that helps generate the pilot arc. Pilot arc contacts, also known as a start cartridge, begin touching the electrode and generate a spark when forced apart by air pressure.

pilot arc starters

A device in a plasma cutting machine that ignites the plasma arc through the movement between the nozzle and electrode. In pilot arc starters, when gas flows into the torch, it separates the nozzle from the electrode, creating a spark that ionizes the gas.

pivots

To turn 180 degrees. Pivoting allows the flow of compressed air to correctly align with the electrode at all times during the air carbon arc cutting process.

plasma

A state of matter created by energizing a gas. Plasma is the fourth state of matter characterized by its high temperature and electrical conductivity.

plasma arc

A stream of plasma used to cut a metal workpiece. The plasma arc, also known as a cutting arc, is formed by an electrode ionizing air or another gas pumped into the torch and heating it to a high temperature.

plasma arc cutting

PAC. A method of cutting metal with a jet of gas that has been ionized by an electric arc to create plasma. Plasma cutting is a quick process that creates high quality cuts.

plasma arc cutting

PAC. A method of cutting metal with a jet of gas that has been ionized by an electric arc to create plasma. Plasma cutting is a quick process that creates high-quality cuts.

plasma cutting machine

The device that channels electricity from the outlet or generator to the torch. Plasma cutting machines come in a range of power levels for various cutting jobs.

plasma cutting torch

The device used in plasma cutting to perform the actual cut on the workpiece. The plasma cutting torch generates the arc and converts gas to plasma.

porous

Full of holes or having many voids. The material inside an acetylene cylinder is porous, allowing the material to absorb acetone, the liquid in which acetylene is dissolved.

positive terminal

A connecting point in a circuit that has a positive charge. Positive terminals and negative terminals are attached to wires, which creates an electrical connection.

positively charged

Having an electric charge with a shortage of electrons. A positively charged material is often symbolized by a plus (+) sign.

pounds per square inch

psi. A unit of pressure used in the English system. Pounds per square inch measures the amount of load pressure that is applied over an area of one square inch.

power density

The rate of power per unit area. Power density is usually measured in British thermal units per square inch (BTU/in.²) or in Watts per square centimeter (W/cm²).

power output

The measurement of energy produced per unit time. Power output is most frequently measured in Watts (W) or in British thermal units per minute (BTU/min).

power source

A device that generates electricity. Arc welder power sources can be plugged into a wall outlet, or they can generate electricity through the use of a mechanical device such as a motor or generator.

preheat flame

A type of flame, ranging from 5,000 – 6,000°F (2,204 – 3,315.56°C), produced by a gas cutting torch. The preheat flame is used prior to cutting a workpiece in order to raise the metal's temperature up to its kindling point.

pre-treatment

Processes used to change the structure of a material and alter its physical and mechanical properties prior to welding and cutting operations. Pre-treatments include heat treating and cold treating.

primary voltage shock

An electrical shock from 120-480 volts. Primary voltage shock can result from touching a lead inside a switched-on power source and touching grounded metal at the same time.

propane

C8H8. A colorless, flammable gas produced as a by-product during the processing of natural gas and the refinement of petroleum. Propane is sometimes used as a fuel gas in the oxyfuel cutting process.

propylene

C3H6. A colorless, flammable gas created during petroleum refinement processes. Propylene is sometimes used as a fuel gas in the oxyfuel cutting process.

psi

pounds per square inch. A unit of pressure used in the English system. The unit psi measures the amount of load pressure that is applied over an area of one square inch.

pulsed lasers

A laser that emits either a single burst or repeating bursts of energy from a laser beam. Pulsed lasers can have up to 500 times higher peak powers than the output power of constant wave lasers, but these peak powers only last for very short periods of time.

pump source

An external device that supplies light to excite and amplify a solid-state lasing medium's energy. Pump sources include flash lamps, arc lamps, and laser diodes.

purity

To be uncontaminated. The purity of oxygen is an important variable within the oxyfuel cutting process.

retaining cup

A piece of a handheld plasma cutting torch that holds the shield cup in place and covers the other consumables. Though often used, retaining caps are only essential when using a drag shield.

robotic multi-axis systems

A laser cutting machine configuration that uses a six-axis robotic arm to move a laser beam over and around a stationary workpiece. Robotic multi-axis systems are fast, precise, and versatile programmable systems that most frequently rely on solid-state lasers with a fiber optic delivery system to produce highly repeatable cuts.

rotary stage

A rotating, cylindrical surface upon which a workpiece rests. Rotary stages are sometimes used during fixed optic laser cutting processes.

safety goggles

A type of tight-fitting eye protection that completely covers the eyes, the sockets, and the surrounding facial area. Safety goggles offer protection from impact, slag, molten metal, and spatter.

safety lock

A part of a hand held plasma torch designed to prevent operators from accidentally pressing the trigger. Safety locks differ between torch models.

sawing

A basic metal cutting process that uses a blade with a series of teeth on its edge to cut a narrow opening in a workpiece. Sawing may be used to produce slots or grooves or to separate the workpiece into two pieces.

secondary voltage shock

An electrical shock from 60-100 volts. Secondary voltage shock can result from touching the electrode while another part of the body touches the workpiece.

semiconductor

A material or element that has more electrical conductivity than an insulator, but less than a conductor. Semiconductor materials used in laser systems include alloys of gallium, aluminum, and silicon.

semiconductor lasers

A device that produce a laser beam by discharging electrical current through a solid lasing medium. Semiconductor lasers include diode lasers, surface-emitting lasers, and quantum cascade lasers.

shearing

A basic metal cutting process that separates sheet metal into smaller sections without forming chips. Examples of shearing include punching, notching, blanking, slitting, lancing, perforating, and parting.

shielded metal arc welding

SMAW. An arc welding process that uses a flux-coated consumable rod electrode. Shielded metal arc welding is also referred to as stick welding.

shielding gases

A gas that protects the cut from atmospheric contamination. Shielding gasses include nitrogen and compressed air and are selected based on the specific job specifications.

six-axis robotic arm

An arm-shaped robot generally mounted on a platform or suspended from a track while the arm reaches to various distances and locations. Six-axis robotic arms are sometimes referred to as manipulators.

slag

A substance created when metal is melted and separated. In thermal cutting processes, slag is usually composed of metal oxides.

solid-state lasers

A device that produce a laser beam by discharging light through a solid medium. Solid-state lasers include Nd:YAG lasers, Nd:Glass lasers, and ruby lasers.

spark lighter

An inexpensive and easy-to-use device that uses friction to safely ignite the fuel gas flowing from an oxyfuel torch. Spark lighters are commonly called strikers.

spatter

Liquid metal droplets and sparks expelled during a thermal cutting or welding process. Spatter, which can spray up to 35 feet (10.67 m) from the work area, is a safety risk that can cause burns or fire.

start circuitry

The method by which the plasma cutting machine starts the formation of plasma. Start circuitry may be either high frequency contact or pilot arc.

striker

An inexpensive and easy-to-use device that uses friction to safely ignite the fuel gas flowing from an oxyfuel torch. Strikers are also called spark lighters.

synthetic materials

Artificial or human-made. Synthetic materials include plastic and nylon.

thermal cutting

A cutting process that uses heat to remove metal from a workpiece. Thermal cutting processes include oxyfuel, air carbon arc, plasma arc, and laser beam.

thermal energy

Energy resulting from the motion of particles. Thermal energy is a form of kinetic energy and is transferred as heat.

thermal expansion

The tendency of a material to increase in size as it increases in temperature. Every material has its own unique rate of thermal expansion.

three-dimensional

3D. Occurring in more than two axes of movement. Three-dimensional cutting operations are often performed by solid-state lasers that are delivered by an optical fiber.

tolerances

An acceptable deviation from a desired dimension that still meets specifications. Tolerances indicate the allowable difference between a physical feature and its intended design.

torch body

The part of the torch held by the cutter or welder. Torch bodies have internal tubes that direct the flow of gases to the mixing chamber.

torch tip

A component at the tip of the plasma cutting torch that directs plasma gas into a narrow jet directed at the workpiece. Torch tips, which are also called nozzles, are one of the main consumables in a plasma torch.

trimming

A shearing operation that removes uneven sections or degraded sections from a previously worked part. Trimming operations are sometime required after thermal cutting processes.

two-dimensional

2D. Occurring only in the axes of length and width. Two-dimensional cutting operations are often performed by gas lasers.

ultraviolet light

UV. Light not visible to the naked eye because it consists of wavelengths shorter than those of visible light. Ultraviolet light is harmful and can damage vision and burn skin.

unstable

Highly reactive, dangerous, and possibly explosive. Unstable materials require careful handling to ensure safety.

vaporizes

To transform a solid or liquid into a gas through the application of intense heat. Powerful lasers are capable of vaporizing metal.

velocity

The combination of an object's speed and direction of motion. The velocity of a plasma arc increases when it constricts to pass through the torch tip.

ventilation

A means of providing fresh air. For the safety of workers, welding and cutting processes requires proper ventilation.

visible light

Wavelengths of electromagnetic radiation that can be seen with the human eye. Visible light is a form of radiation.

vortex

A mass of gas or fluid moving in a circular, whirling motion. A vortex usually has a clearly defined center.

wall-plug efficiency

A measure of the optical energy output of a laser system versus the total electrical energy supplied to it. Wall-plug efficiency is expressed as a percentage.

water-cooled

A type of torch that uses water as a coolant. Water-cooled torches often operate at a higher duty cycle than air-cooled torches.

watts

W. A unit of measurement for the wattage or power used in or produced by a circuit. Watts require a change in energy to exist.

wavelength

The length of a light wave. Wavelengths determine the color and visibility of the light.

weld defects

An irregularity in a weld that exceeds the part design tolerances. Weld defects are rejectable discontinuities, which are determined by welding code.

welding helmet

A protective eye and face device worn during welding and cutting processes. Welding helmets protect a welder from harmful rays and intense bright light that welding and cutting processes produce.

welding hood

Any device that uses suction to remove from the environment the smoke and gases generated during welding and cutting processes. Welding hoods are sometimes called fume extractors.

work leads

An electric wire that conducts electricity between a power source and workpiece. Work leads can be powered by either DC or AC.

workholding device

A device used to support, locate, and hold a workpiece for manufacturing purposes. Workholding devices range from simple vises and clamping kits to microprocessor-controlled fixturing systems.

workpiece

A part that is being worked on during manufacturing. Workpieces may be subject to cutting, welding, forming, or other operations.

workpiece lead

An electric wire that connects a power source to a workpiece. The workpiece lead is most frequently attached to a power source's negative terminal when performing air carbon arc cutting.

X axis

The linear axis representing motions and positions along a line parallel to the longest edge of the worktable. The X axis is perpendicular to the Y axis.

X-Y coordinate system

A numerical system used to describe the location of an object in two-dimensional space. An X-Y coordinate system expresses the distance from any point to the fixed intersection of two linear axes: X and Y.

Y axis

The linear axis representing motions and positions that travel the shortest distance parallel to the worktable. The Y axis is perpendicular to the X axis.