There are a variety of different options in weld studs used in different industries and for different applications. There are also some basic similarities, so knowing specifically what the use is for the weld stud will be essential in choosing the right type, alloy, design, style, and length.
One type of weld used across many different industries and typically with CD welding systems are the projection weld studs. These are easy to identify as they have a small protrusion or projection, correctly known as an ignition tip, which is found on the bottom of the weld stud where it will make contact with the workpiece.
The Function of the Ignition Tip
When using projection weld studs, the stud weld gun creates an electric arc between the ignition tip, the protrusion of metal, and the workpiece surface. This creates molten metal on both the bottom of the stud weld and the surface of the base metal. In essence, the actual base on the stud weld itself doesn’t melt, but the length of the attached stud weld will be slightly shorter as the ignition tip is now the material used in forming the weld.
As the weld stud moves down in the cycle and makes contact with the surface, this molten material mixes, creating a solid bonded area which is as strong as both the workpiece as well as the weld stud.
Styles and Options
There are different options in projection weld studs which create different head shapes and different patterns of protrusions. There may be more than one protrusion based on the shape of the head and the area which will need to form the weld.
Some types of larger stud welds will have three or more ignition tips, even with a standard circular shape. This allows for a uniform distribution of molten material and a complete, solid and sealed weld around the base.