Arc [Arc Length] – The physical gap between the end of the electrode and the point where the arc makes contact with the base metal.
Duty-cycle – As per EN/AS50974.1, the minutes out of a 10-minute period a welder / welding machine can be operated at maximum rated output. For example, a 60% duty cycle @ 300 Amps means that the welding machine can be used for 6 minutes (at 300 Amps) and then must be allowed to cool with the fan running for 4 minutes. This reduces the chance of heat damage to the system. This rating is given at an ambient temperature of 40 degrees celcius. Cooler ambient temperatures increase duty cycle.
Electrode – A flux coated metal wire having the same composition as the material being welded.
Flux – The coating on arc-welding rods and in flux-cored welding wire that is consumed in order that the arc can produce it’s own shielding gas. The gas displaces air and impurities from around the weld.
Ground Lead/ Workpiece Lead – The copper cable and clamp that is exceptionally flexible and is connected between the welding machine and the workpiece.
Rated Output – The Amps and voltage the welding power source will produce for a given duty-cycle period. For example, 200 Amps, 22 load volts @ 30% duty-cycle.
Shielding Gas - Protective gas used to prevent atmospheric contamination of the weld pool. Usually a mixed gas or CO2.
Slag – A layer of flux soot the protects the weld from oxides and other contaminants while the weld is solidifying (cooling). Slag is to be removed after cooling.
Spatter – Metal particles thrown from the weld, often cooling and hardening on the work surface. A spatter-resistant spray applied to the workpiece can minimize spatter.
Torch – A device in the TIG process to control the position of the electrode, to transfer current to the arc and to direct the flow of shielding gas.
Tungsten – A rare metallic element with an extremely high melting point in the range of 5000 degrees celcius used for TIG electrodes. Some variants may contain radioactive elements.
Wire Feed Speed - Expressed as in//min. or mm/s and refers to the speed and amount of filler metal fed into a weld. The higher the wire feed speed, the higher the amperage.