You have got to decide upon the type of welding those requirements to be used upon this basic factor. Depending upon the work that you have at hand, you will have to spot the best way to get it done using a welding techniques that suitable to the task perfectly. There are few types of welding tasks.
It is prominence among professionals for it great quality welds. Decide upon a welder type depending upon the quality requisite for the welding task. If you need great quality for products that are very noticeable then TIG is the way to go. Sometimes TIG weld is completed after making a pipe joint weld.
Select a type of equipment keeping in mind the thickness of the material that needs to be welded. MIG or Stick process cannot be use old for metals which are thousand of inch in thickness. This is because they heat up the metal way too much than desirable. Whereas, they will serve to be the best selection while welding metals that are ½" in thickness. They cut them much quicker and efficiently.
Make a decision upon the power of the machine that is required to finish the weld. People who do welding as a hobby would not require the elevated tech TIG to do trivial welding tasks. This will not be the case with manufacturing welding where power is the key.