Generally (but not always) pronouns stand for (pro + noun) or refer to a noun, an individual or individuals or thing or things (the pronoun's antecedent) whose identity is made clear earlier in the text. For instance, we are bewildered by writers who claim something like. They say that eating beef is bad for you.
A wire feeder may be used for machine or automatic welding and must be the constant speed type. The wire feeder must have a speed adjustment covering the range of from 10 in. per minute (254 mm per minute) to 125 in. per minute (3.18 m per minute) feed speed. PAW or plasma arc welding using an automated process.
This wire or filler material is fed through a welding gun. The power source is used to start and maintain the arc between the wire and the base metal. GMAW or MIG welding utilizes solid metal wire, which requires the use of a shielding gas to protect the weld puddle from the atmosphere.