For those new to different types of welding processes, making a choice in projection welding or spot welding can be difficult. There are some key factors to consider in the differences of the two processes, including the difference between the weld studs themselves.
The types of studs used for spot welding, which uses resistant welding technology and methods, look just like standard bolts or rods, depending on the type of weld stud in use. With projection weld studs, as the name implies, there is a small protrusion or ball at the bottom of the weld stud.
This is the material that will be used to melt and fuse the projection weld studs with the base metal once the molten pool is formed. Pressure from the stud weld gun is also used to force the weld stud down and into the molten material for a complete, even seal all around the weld stud base.
The Advantages
There are several advantages to using project welding and projection weld studs for any project. It is particularly effective when there are multiple weld studs to be placed and when speed and precision of placement is a critical consideration.
With the use of the drawn arc or capacitive discharge system of stud welding, there is no heating of the workpiece or the stud except for the small metal on the projection and the area immediately under the stud. Within just fractions of a second, the electrical current generates the heat to melt the workpiece and the stud, which means no discoloration or marring around the weld area.
There are different styles and options in weld studs that are used in projection welding. This includes the shape of the head of the stud as well as the location and placement of the projections around the head.