The following glossary of welding terms of definitions is designed to get anyone quickly up to speed on the welding, brazing, soldering and metal working industry terminology.
Welding Terms (A – C)
Alloy | A metal consisting of a mixture of two or more materials. One of these materials must be a metal. |
Aluminum | A silver-white metal that is soft, light and conductive. |
Aluminum Oxide | A chemical compound of aluminum and oxygen, which forms a thin layer on the surface of aluminum when exposed to air. Aluminum oxides should be removed before welding. |
Annealing | The steady heating of a metal at a certain temperature followed by a gradual cooling process. Annealing is often used when welding nonferrous metals. |
Arc Welding | A fusion welding process that uses electricity to generate the heat needed to melt the base metals. To join two pieces of metal into one solid piece the heat of an electric arc is concentrated on the edges of two pieces of metal to be joined. The metal melts, while the edges are still molten, additional melted metal is added. This molten mass then cools and solidifies into one solid piece. |
Argon | A colorless, odorless type of inert gas. Argon is commonly used as a shielding gas. |
Austenitic Stainless Steel | Stainless steel with very high strength, as well as excellent ductility and toughness. Austenitic stainless steel is the most corrosion resistant stainless steel. |
Base Metal | One of the two or more metals to be welded together to form a joint. |
Boiling Point | The temperature at which liquid changes to a vapor. The boiling point of zinc is below the melting temperature of most steels. |
Brass | An alloy of zinc and copper. Brass has poor weldability. |
Bronze | An alloy of zinc and copper. Bronze is the most weldable of the copper alloys. |
Burn through | Excessive melt through or a hole in the base metal. Extremely high welding temperatures can cause burn through. |
Cast Nickel Alloy | An alloy containing nickel that has been poured as a liquid into a mold and cooled into a solid shape. Cast nickel alloys are often difficult to weld because of their high silicon content. |
Cold Working | The shaping of metal at temperatures substantially below the point of recrystallization. Cold working adds strength and hardness. |
Compressive Strength | A metal’s ability to resist forces that attempt to squeeze or crush it. |
Copper | A reddish metal that is very ductile, thermally and electrically conductive, and resistant to corrosion. |
Copper-lead Alloy | An allow containing lead and copper, which has the poorest weldability because the toxic lead often contaminates the weld. |
Copper-tin Alloy | An alloy containing tin and copper, which is the most weldable of the copper alloys. Tin adds hardness and strength to copper. Copper-tin alloys are also known as bronze. |
Copper-zinc Alloy | An alloy containing zinc and copper, which has poor weldability and tends to give off offensive fumes. Copper-zinc alloys are also known as brass. |
Corrosion Resistance | A metal’s ability to resist attack by other elements and chemicals. |
Cracking | A fracture that develops in the weld after solidification is complete. Welds with high hardness can cause cracking. |
Welding Terms (D – L)
Ductility | A metal’s ability to be drawn, stretched, or formed without breaking. |
Electrical Conductivity | A metal’s ability to conduct an electrical current. |
Electrode | A device that conducts electricity. In arc welding, the electrode also can act as the filler metal. |
Ferrous Metal | A metal that contains iron. Steel is the most popular ferrous metal. |
Filler Metal | A type of metal sometimes added to the joint in fusion welding. Filler metal adds to the strength and mass of the welded joint. |
Galvanizing | The process of adding a zinc coating to steel. Galvanized steel is used to manufacture car parts, building frames, and ducting. |
Gas Torch | A device that emits heat in the form of a gas. |
Gauge | A standard of measure used to determine a specific thickness of sheet metal. |
Grain Structure | The relationship between the small, individual crystals in an alloy or metal. |
Grinding | The use of an abrasive to wear away at the surface of a workpiece. |
Hardness | A metal’s ability to resist indentation, penetration, and scratching. The heat from welding may change a metal’s hardness. |
Heat Treatment | The controlled heating and cooling processes used to change the structure of a material and alter its mechanical and physical properties. |
Heat-affected Zone | The portion of the base metal that has not been melted, but its mechanical properties have been altered by the heat of welding. |
Heat-treatable Alloy | Alloys that can be heated after welding to restore their strength properties. |
Joint | The meeting point of the two materials that are joined together. Welding creates a permanent joint. |
Lead | A soft, heavy, toxic metallic element. Lead is often used in gasoline. |
Welding Terms (M – S)
Magnesium | A grayish white, extremely light metal that is also brittle and has poor wear resistance. |
Magnum Gun | MIG welding guns and TIG welding torches are hand-held welding application tools connected to both the wire feeder and power source. They direct the welding wire to the weld joint and control the wire feed with the use of a trigger mechanism. |
Mechanical Properties | The properties that describe a material’s ability to compress, stretch, bend, scratch, dent or break. |
Melting Temperature | The temperature necessary to change a metal from solid to a liquid. Also known as a melting point. |
MIG Welding | Constant Voltage and Constant Current welders are used for MIG welding and are a semi-automated process when used in conjunction with a wire feeder. Wire is fed through a gun to the weld-joint as long as the trigger is depressed. This process is easier to operate than stick welding and provides higher productivity levels. CC/CV welders operate similarily to CC (MIG) welders except that they possess multi-process capabilities – meaning that they are capable of performing flux-cored, stick and even TIG processes as well as MIG. |
Nickel | A hard, malleable, silvery white metal used in various alloys to add strength, toughness, and impact resistance to metals. |
Nonferrous Metal | A metal that does not contain iron. Aluminum and copper are common nonferrous metals. |
Non-heat Treatable Alloy | Alloys that rely primarily on cold working to increase their strength properties. |
Oxyfuel Gas Cutting | Oxyfuel gas cutting process involves preheating the base metal to a bright cherry red, then introducing a stream of cutting oxygen which will ignite and burn the metal. |
Physical Properties | The properties that describe a metal’s ability to melt, emit heat, conduct electricity, and expand or shrink. |
Post heating | The application of heat to the weld immediately after welding. Post heating helps to reduce stress in the weld metal. |
Plasma Cutter | A constricted cutting arc is created by this machine, which easily slices through metals. A high-velocity jet of ionized gas removes molten material from the application. |
Precipitate | The separation of elements from a type of solution. Elements that precipitate out of a solution change a metal’s properties. |
Precipitation Hardening | The process of heating to a temperature at which certain elements precipitate, forming a harder structure, and then cooking at a rate to prevent a return to the original structure. |
Preheating | The application of heat to a base metal immediately before welding. Preheating helps reduce hardness in the metal. |
Properties | A characteristic of material that distinguishes it from other materials. |
Quality Assurance | Quality Assurance (QA) is a set of defined processes and actions for systematic monitoring and evaluation to ensure a safe, effective, and high-quality product. |
Quality Control | Quality control (QC) is the set of test procedures used to verify that a product meets the manufacturing specifications. It involves checking and testing both the manufacturing procedures and the quality of the final products. |
Recrystallization | The formation of a new grain structure. Recrystallization is often the result of annealing. |
Robotic Welding | The combination of a robotic arm, a welding power source and a wire feeder produces welds automatically using various programs, welding fixtures and accessories. |
Silicon | A nonmetallic element often found in sand and used to make glass. High amounts of silicon in a weld can cause cracking. |
Stick Electrode | A short stick of welding filler metal consisting of a core of bare electrode covered by chemical or metallic materials that provide shielding of the welding arc against the surrounding air. It also completes the electrical circuit, thereby creating the arc. (Also known as SMAW, or Stick Metal Arc Welding.) |
Stick Welding | Heating the coated stick electrode and the base metal with an arc creates fusion of metals. An AC and/or DC electrical current is produced by this machine to create the heat needed. An electrode holder handles stick electrodes and a ground clamp completes the circuit. |
Solution Heat Treating | A heat treatment method used to heat an alloy to a specific temperature for a certain period of time to allow one or more alloy elements to dissolve in a solid solution and then cool rapidly. |
Steel | A metal consisting of iron and carbon, usually with small amounts of other elements. Steel is the most common manufacturing metal. |
Strength | A meal’s ability to resist outside forces that are trying to break or deform the metal. |
Supersaturated Solution | A solution that is completely filled with alloying elements. |
Welding Terms (T – Z)
Tack Weld | A weld made to hold the parts of a weld in proper alignment before the final welds are made. Tack welds are also used to aid in preheating. |
Tensile Strength | A metal’s ability to resist forces that attempt to pull it apart or stretch it. |
Thermal Conductivity | The rate at which heat flows through metal. |
Thermal Expansion | The increase in the dimensions of a metal due to an increase in its temperature |
TIG Welding (GTAW) | A less intense current produces a finer, more aesthetically pleasing weld appearance. A tungsten electrode (non-consumable) is used to carry the arc to the workpiece. Filler metals are sometimes supplied with a separate electrode. Gas is used for shielding. (Process is also known as GTAW, or Gas Tungsten Arc Welding.) |
Tin | A silver-white soft metal used in many alloys. Tin is often used to coat other metals to prevent corrosion. |
Titanium | A silver-gray, strong, but lightweight metal known for its corrosion resistance. Titanium is often used in the aerospace industry. |
Toughness | A metal’s ability to withstand a sharp blow. |
Weave | Movement of the electrode in a back and forth motion to deposit weld metal into a joint. |
Weld | A mix of metals that joins at least two separate parts Welds can be produced by applying heat, or pressure, or both heat and pressure, and they may or may not use an additional filler metal. |
Weldability | The ability of a material to be welded under imposed conditions into a specific, suitable structure and to perform satisfactorily for its intended use. |
Wrought Nickel Alloy | An alloy containing nickel that has been bent, hammered, or physically formed into a desired shape. Wrought nickel alloys are often welded under the same conditions as certain types of steel. |
Yield Strength | A metal’s ability to resist gradual progressive force without permanent deformation. |
Zinc | A bluish white metal that is corrosive resistant and has a relatively low melting point. Zinc is often used as a coating on steel. |