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.
Welding with DC Reverse and Straight Polarity. In the early days of arc welding, when welding was done with bare metal electrodes on steel, it was normal to connect the positive side of the generator to the work and the negative side to the electrode.