Plasma Cutting 283

“Plasma Cutting” describes plasma cutting equipment and discusses the setup and operation steps for plasma cutting, gouging, and piercing. Plasma cutting is a precise and efficient cutting method that uses an ionized jet of gas to generate a high temperature cutting arc and can be done by hand or with the use of CNC machine.

Plasma cutting is an increasingly affordable and popular method of metal cutting. Plasma cutting balances the lower cost of cutting methods such as oxyfuel with the higher quality of laser cutting methods. After this class, users will be able to define plasma cutting, identify the tools used in plasma cutting, and describe the various cutting applications and processes. Understanding the basic plasma cutting functions and processes is essential for users to make precise, accurate cuts safely and efficiently.

Class Details

Class Name:
Plasma Cutting 283
Version:
2.0
Difficulty:
Intermediate
Number of Lessons:
21
Related 1.0 Class:
Plasma Cutting 265

Class Outline

  • Plasma Cutting
  • Plasma Cutting Safety
  • Advantages and Disadvantages of Plasma Cutting
  • Introduction to Plasma Cutting Review
  • Plasma Cutting Systems
  • The Plasma Cutting Torch
  • Starter Types
  • Plasma Cutting Torch Operation
  • Air Flow Control
  • Cutting Guides
  • Plasma Cutting Tools Review
  • Preparing a Cut
  • Steps for Cutting
  • Plasma Gouging
  • Plasma Piercing
  • Hand-Held Plasma Cutting
  • Plasma Cutting Steps Review
  • Basic Troubleshooting
  • Mechanized Plasma Cutting
  • CNC Plasma Cutting
  • CNC and Troubleshooting Review

Objectives

  • Describe plasma cutting.
  • Describe the best safety practices for plasma cutting procedures.
  • Contrast the advantages and disadvantages of plasma cutting.
  • Describe the basic function of a plasma cutting system.
  • Describe the components that make up a plasma cutting torch.
  • Describe the types of starters used in plasma cutting systems.
  • Describe the gas flow control system for plasma cutting.
  • Describe how cutting guides are used in plasma cutting.
  • Describe how to set up for a plasma cutting operation.
  • Describe the steps involved in manual plasma cutting.
  • Describe plasma gouging.
  • Describe plasma piercing.
  • Explain basic troublehooting procedures for plasma cutting.
  • Describe the mechanized plasma cutting process.

Job Roles

Certifications

Glossary

Vocabulary Term Definition
air compressor A component that pressurizes ambient air and directs it into a plasma cutting machine. Air compressors provide the gas that becomes ionized.
air flow control The regulation of gas flowing to the torch. Air flow control is achieved with a flow control valve.
air pressure gauges A device that measures the flow from the gas source to the torch. Air pressure gauges help operators know when to adjust the regulator.
alternating current AC. An electrical current that reverses direction at regularly recurring intervals of time. AC is more easily converted to higher and lower voltages.
aluminum A silver-white metal that is soft, light, and thermally conductive. Aluminum is corrosion resistant, has a high strength-to-weight ratio, and can be cut using a plasma cutter.
amperes A. A unit of electrical measurement that describes the amount of electricity and the time it takes to travel a certain distance. Amperes are also called amps.
arc The space in which electricity jumps from the electrode to the workpiece. In plasma cutting, the heat generated by the arc is the primary heat source that cuts the metal.
arc height control A system that can be added to CNC plasma cutting machines that measures and adjusts the length of the cutting arc. Arc height control systems can greatly improve cut quality.
arc welding A joining process that uses an electric arc to melt and fuse metals together permanently. Arc welding and plasma cutting both use electricity to generate heat.
atmospheric contamination An impurity or gas in the surrounding air that causes a defect to form in the weld. Shielding gases prevent atmospheric contamination.
bevels An edge or surface of an object that is set at a sloping angle. In plasma cutting, cutting guides make it easier to cut bevels into a workpiece.
carbon steel The most basic form of steel containing less than 3.0% alloying elements. The amount of carbon in a carbon steel determines its hardness and weldability.
CNC Computer numerical control. A programmable combination of software and hardware directed by mathematical data that controls the operation of a machine. CNC machines are used to carry out various machining operations, including plasma cutting.
cold plasma An ionized gas produced in a specialized environment that allows for ionization at lower energy levels and, therefore, has lower temperatures. Cold plasmas are used in a number of household products such as plasma televisions and florescent lights.
compressed gas cylinders A metal container used to hold gases under pressure for manufacturing purposes. Compressed gas cylinders need to be handled carefully as they hold materials, which may or may not be flammable, under high pressure.
computer numerical control CNC. A programmable combination of software and hardware directed by mathematical data that controls the operation of a machine. CNC machines are used to carry out various machining operations, including plasma cutting.
computer numerical control CNC. A programmable combination of software and hardware directed by mathematical data that controls the operation of a machine. Computer numerical control machines are used to carry out various machining operations, including plasma cutting.
condense The process of concentrating a gas into a liquid by reducing its temperature. Water vapor condenses into liquid water.
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.
consumables Any part of a plasma cutting machine that may wear over time or through usage. Consumables include electrodes, nozzles, and gas distributors.
current The flow of electricity. Current is measured in amps.
cutting arc A stream of plasma used to cut a metal workpiece, also known as a plasma arc. Cutting arcs are formed by an electrode ionizing air or another gas pumped into the torch and heating it to a high temperature.
cutting guide A device that attaches to the plasma torch and restricts its movement to ensure proper cutting. Cutting guides come in a variety of forms such as straight, circular, and bevel.
cutting speed The speed at which an operator or machine should move the plasma cutting torch over the workpiece. Cutting speed is indicated in inches per minute (IPM) or millimeters per minute (mm/min).
direct current DC. An electrical current formed when electrons flow in one continuous direction. All plasma cutters operate using DC current.
drag shield A component that mounts on the front of a hand held plasma torch in order to prevent it from getting too close to the workpiece. Drag shields are also known as shield cups.
dross A scum formed by workpiece surface oxidation that sometimes contains solidified metal. Dross is difficult to remove and indicates a problem with the plasma cutting machine or process.
ductwork A system designed to deliver and remove air. Ductwork is a connected system constructed from thin sheets of metal.
electric shock The flow of electricity through the body. Severe electric shock can be fatal.
electrical conductivity The ability of a material to act as a medium for conveying electricity. Ionized matter has high electrical conductivity.
electrode A consumable device in a plasma torch that forms one end of the arc. Electrodes usually have an insert in the tip made from tungsten or hafnium, which are metals that have very high melting points.
electromagnetic field An area of force that is generated from the motion of electrical charge and current. The strength of electromagnetic fields depends on the strength of the charge and current of the electricity that generates them.
filter plates The shaded protective lens inside a welding helmet that filters out harmful rays and intense bright light. The amount of shading required on a filter plate depends on the specific procedure such as welding or plasma cutting.
filters A device that removes contaminants from the air. Depending on their construction, filters can remove particulates and chemicals from the air.
frequency The rate at which an electrical current alternates, expressed as the number of cycles per unit of time. Frequency is typically measured in Hertz (Hz) or cycles per second.
fume extractor A device that uses suction to remove smoke and gases generated by plasma cutting from the environment. Fume extractors come in a range of sizes and can be used in a variety of work settings.
fume extractors Devices that use suction to remove from the environment the smoke and gases generated by plasma cutting. Various types of fume extractors can be used for different applications.
fumes A cloud of particles suspended in a gas. Manufacturing applications that emit fumes require proper ventilation.
gas distributor The device that swirls the plasma gas to keep it centered on the electrode and the nozzle opening. Gas distributors are also known as swirl rings.
gouges An indentation or groove. Gouges on a plasma cutting torch's nozzle indicate wear which can lower cut quality.
gouging A plasma torch component required for operations that remove unwanted workpiece metal. Gouging nozzles have a wider opening than plasma cutting nozzles.
gouging nozzle A plasma torch component with a narrow opening that allows operators to create a groove in a workpiece. Gouging nozzles are consumables, so they wear over time and need to be replaced.
grind To use an abrasive to wear away at the surface of a workpiece. Grinding is often used to clean contaminants from the surface of a workpiece.
grounding A means of providing a safe path for electricity should it stray from its intended path. Grounding can prevent high frequency start systems from interfering with nearby electrical equipment.
heating, ventilation, and air conditioning HVAC. A series of related climate control systems. Heating, ventilation, and air conditioning systems, such as ductwork, are often made with automated plasma cutting systems.
high frequency contact starter 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.
humidity The amount of vaporized water in the air. Excessive humidity can cause a plasma cutting torch to malfunction.
inches per minute IPM. A unit of measurement for speed that indicates how many inches the plasma cutting machine or operator should travel over the workpiece in a minute. Cutting using the proper IPM rate will ensure the highest quality cuts.
infrared Invisible rays of radiant energy that are emitted during the plasma cutting process. Infrared rays can damage vision.
interference A disturbance that affects an electrical system. Interference can cause machines to malfunction.
inverters A device that greatly increases the frequency of the electricity supplied by the electrical utility. Inverters allow for the use of smaller, lighter transformers resulting in smaller cutting and welding machines.
ionized A negatively or positively charged atom or collection of atoms. Ionized gases are called plasmas and are positively charged when used in plasma cutting.
laser A device that generates an intense beam of light that can be precisely aimed and controlled. Lasers are used for a wide array of manufacturing processes including cutting metals.
lead A bluish-white metal that is very soft and ductile and is a poor conductor of electricity. Lead is toxic and produces harmful fumes when vaporized through work processes.
malfunction An equipment's failure to properly perform a task. Malfunctions can be hazardous to operators.
millimeters per minute mm/min. A unit of measurement for speed that indicates how many millimeters the plasma cutting machine or operator should travel over the workpiece in a minute. Cutting using the proper mm/per minute rate will ensure the highest quality cuts.
multi-axis Movement in multiple directions, including both linear and rotational movements. Multi-axis cuts can be much more complex than a single linear cut.
nitrogen An inert gas that makes up 78% of breathable air. Pure nitrogen is used as a shielding gas and as a plasma gas for some processes.
nozzle A component at the tip of a plasma cutting torch that directs plasma into a narrow jet directed at the workpiece. Nozzles are one of the main consumables in a plasma torch.
nylon A plastic material that is often used to create fibers for synthetic fabrics. Nylon fabrics can melt in the presence of the extreme heat.
oxidation A metal's chemical reaction with oxygen. Oxidation can cause tarnish and rust on a metal's surface.
oxyfuel A mix of oxygen and a fuel gas that is used to fuel a flame for welding and cutting metal. Oxyfuel cutting is less precise than plasma cutting.
oxygen A colorless, odorless, tasteless gas that naturally exists in the atmosphere. Oxygen is often used as a plasma gas when cutting carbon steel.
pacemakers A small medical device that is implanted in the chest to control an abnormal or inconsistent heartbeat. Pacemakers can malfunction around high frequency starters.
personal protective equipment PPE. Any piece of safety gear that employees wear or use to prevent injury in the workplace. Personal protective equipment includes welding masks and gloves.
piercing The process of using a plasma cutting torch to create a hole in a metal workpiece. The piercing process is hard on the torch and consumables.
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, also known as a start cartridge, that helps generate the pilot arc. Pilot arc contacts begin touching the electrode and generate a spark when forced apart by air pressure.
pilot arc starter 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.
pitting A form of corrosion that appears as a number of small holes in a material. Pitting on a plasma cutting electrode is an indicator that the electrode needs to be replaced.
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, also known as a cutting arc. Plasma arcs are formed by an electrode ionizing air or another gas pumped into the torch and heating it to a high temperature.
plasma cutting A method of cutting metal that uses plasma,which is a jet of gas that has been ionized by an electric arc. Plasma cutting is a quick process that creates high quality cuts.
polyester A plastic material that is often used to create fibers for synthetic fabrics. Polyester fabrics can melt in the presence of the extreme heat.
power source A device that channels electricity. Plasma cutting power sources can be plugged into a wall outlet, or they can generate electricity through the use of a mechanical device like a motor or generator.
punctures A small hole created by force. Punctures cause damage to mechanical equipment that can be hazardous to operators.
regulators A valve that allows an operator to precisely control the air pressure of the gas being fed to the plasma cutting torch. Flow control valves help ensure efficient cutting.
respiratory Any object or processes relating to the organs involved in the breathing of air. Respiratory organs include the nose, esophagus, and lungs.
retaining cap A piece of a hand held 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.
rivets A type of non-threaded fastener that consists of a shank and a head made of deformable material. Rivets are inserted through holes and are hammered into a matching head on the other side of the part.
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.
shield cup A component that mounts on the front of a hand held plasma torch in order to prevent it from getting too close to the workpiece. Shield cups are also known as drag shields.
shield gas A gas that protects a cut from atmospheric contamination. Shield gases include nitrogen and compressed air, are selected based on the specific job specifications, and are also known as shielding gases.
shielding gas A gas that protects a cut from atmospheric contamination. Shielding gases include nitrogen and compressed air, are selected based on the job specifications, and are also known as shield gases.
standoff distance The space that should be left between a tool and the workpiece it is modifying. Standoff distance helps determine the quality of the cut and affects the life of consumables.
start cartridge A part in a plasma cutting torch, also known as a pilot arc contact, that helps generate the pilot arc. Start cartridges begin touching the electrode and generate a spark when forced apart by air pressure.
start circuitry The method by which a plasma cutting system starts the formation of plasma. Start circuitry may be either high frequency contact or pilot arc.
state of matter The form matter takes, depending mostly on temperature and pressure. The states of matter are solid, liquid, gas, and plasma.
steel An alloy of iron and carbon containing less than 2.0% carbon. Steel often contains other elements to enhance various properties of the metal.
straight edge A piece of metal with a linear side used to help operators cut straight lines. Straight edges can refer to any metal with a linear side that can be clamped to the workpiece.
swirl ring The device that swirls the plasma gas to keep it centered on the electrode and the nozzle opening. Swirl rings are also known as gas distributors.
synthetic An artificial or manufactured material. Synthetic materials include nylon and polyester and ignite easily.
tack welds A weld that holds workpieces in proper alignment for a final welding process. Tack welds are also used to aid in preheating.
torch The device used to perform the actual cut in plasma cutting. Gas is pumped into the torch and converted to plasma at the tip.
trigger A component on a hand held plasma cutting torch that, when pulled, starts the arc. Some triggers have safety locks that must be turned off to allow the arc to start.
ultraviolet UV. Invisible rays of radiant energy that the arc emits during plasma cutting. UV rays can damage vision and burn skin, and long-term exposure can increase the risk of skin cancer.
UV Ultraviolet. Invisible rays of radiant energy that the arc emits during plasma cutting. UV rays can damage vision and burn skin, and long-term exposure can increase the risk of skin cancer.
ventilation A means of providing fresh air. For the safety of the operator, plasma cutting requires proper ventilation.
ventilation A means of providing fresh air. Ventilation is often required for the safety of the plasma cutting operator.
voltage A measure of electrical pressure or potential known as electromotive force. Voltage is measured in volts.
volts A unit of measurement for electromagnetic force or pressure. Volt measurements express the potential energy of a system.
water jet A cutting method that uses a powerful, high velocity stream of water to cut through materials. Water jet cutting processes often use an abrasive material to increase the cutting abilities of the water jet.
welding mask A piece of personal protective equipment that consists of a hard face-guard and a dark tinted viewing lens. Welding masks protect operators from flying sparks and the intense light of the plasma cutting arc.
work clamp The device used to connect the work lead to the workpiece. Work clamps are usually spring-loaded metal pincers that can fit workpieces of various shapes and sizes.
work lead A cable that provides a path for the current flowing from the torch to return to the plasma cutting machine, creating a complete circuit. Work leads are sometimes incorrectly referred to as "grounds."
workpiece A part that is subjected to a manufacturing process such as cutting or welding. Workpieces include any metals or materials undergoing a cutting process.
zinc A bluish-white metal that is corrosion resistant and has a relatively low melting point. Zinc produces hazardous fumes when exposed to high heat.