Mig contact tips are used to provide a conductive path for solid wire electrode in mig gun. They ensure the wire is in the right position inside the torch and maintain right distance between wire & workpiece.
MIG contact tips are available in various sizes, from 0.024 to 0.094 inches. Standard Copper, Copper-Chrome-Zirconium, Silver-Plated, Heavy Duty Silver-Plated CuCrZr, and Stainless Steel X8CrNi18-9 are the five primary types of contact tips available to use.
Five Basic Contact Tips Types
MIG contact tips are available in various types based on their materials. Lets discuss them broadly.
01. Standard Copper Welding Contact Tip
Copper is one of the most reliable materials for MIG contact tips as it has an increased current transfer rate. The electrical conductivity of copper is higher than 55 S/m*. Its higher electrical conductivity ensures a fast, reliable, and non-destructive welding joint. Due to its higher conductivity, you can achieve consistent wire feeding with minimal drag and fewer potential quality problems too.
Manufacturers mainly use CDA C12200 (P deoxidized copper) grade copper for MIG contact tips. This type of gun tip is widely used for handy welding applications.
Standard copper welding contact tip benefits the projects where high wear characteristics and resistance to softening are required.
02. Copper-Chrome-Zirconium Welding Contact Tip (CuCrZr)
This type of contact tip has a tougher copper alloy, making it an ideal choice for automatic and robotic welding projects.
When you need an accurate TCP for achieving consist and repeated welding, this material comes as a savior. It also helps maintain a perfect welding position.
Besides, you can use CuCrZr contact tip for a 100% duty cycle welder to weld nonstop without any breaks.
In addition, it has a decent thermal and electrical conductivity. Its mechanical hardness and strength can be as high as 83 ‘R’B. The contact tip can resist up to 525 degrees Celsius heat.
So you can utilize this contact tip for the hot wire GMAW process to create yields with lower dilutions & low distortion.
03. Silver-Plated Welding Contact Tip
Compared to copper-based contact tips, silver is around 17% denser. Its electrical conductivity is approximately (62.1 S/m), which is also higher than copper.
It can decrease micro-arcing, ensuring better arc starts. It can enhance contact tip durability, deliver smooth welding, and increase overall welding performance.
Additionally, the silver-plated welding contact tip has a higher melting point, which can signify stronger noncovalent intermolecular forces and, therefore, less vapor pressure.
Due to its minimal spatter adhesion and build-up, you will able to avoid serious defects in a weld. Plus, there will be no welding splashes on gas nozzles and workpiece surfaces.
One of the primary reasons people prefer to use silver-plated welding contact tips is its reduced downtime and low levels of proximity failure.
04. Heavy Duty Silver-Plated CuCrZr Contact Tip
A solid-state diffusion process, called dispersion-hardening, is used to make a heavy-duty silver-plated CuCrZr contact tip. Manufacturers add increased strength properties with superior tensile strength at elevated temperatures to create this type of contact tip. That’s why its hardness level is up to 180.
It can endure up to 800°C (1472 °F) temperature without decreasing the working life of the contact tip. The heavy-duty silver-plated CuCrZr contact tip won’t get soften while feeding the wire.
Hence, you won’t have to worry about problems like reduced conductivity, arc-start issues, contact tip burn back, and low-quality welds. Besides, it offers a higher conductivity that will help you achieve better arc starts and a very stable arc.
05. Stainless Steel Contact Tip X8CrNi18-9
This type of contact tip is made from austenitic stainless steel, which has high strength and good corrosion/oxidation resistance.
Besides, it has outstanding cryogenic properties and high-temperature strength. So it is less likely to warp or deform during the welding process.
The hardness level of this type of contact tip is around 230 HB. You can utilize the contact tip for any difficult metal pieces to work with at normal temperatures.
This type of contact tip is ideal for laser welding optics because it can withstand hot wire feeding processes and take a load of the increased weight of weld deposition.
Why Is MIG Contact Tip Important?
A MIG contact tip has a significant impact on the welding process. Tips work as a medium to transfer current from mig welder to the mig wire. Without flowing current to the wire, there won’t be any arc produced and as a result no weld will be generated.
The wire and contact tip must be matched to each other. Otherwise, it will affect the overall welding result. For instance, a 1/8″ wire requires a 1/8″ contact tip.
However, the ID size needs to be a bit larger than the wire and contact tip. It will ensure a disruption-free passing. But the ID size can’t be too short or too large. Otherwise, it will not allow smooth wire passing or produce an imbalanced arc.
You must choose a right contact tip size for your mig gun. otherwise MIG contact tip will result in poor electrical conductivity and micro-arcing. It will negatively affect your overall welding job.
The overall consumable costs will be higher, and the downtime will be more due to the excessive changeover of the contact tip. That’s why you can’t compromise with contact tip if you want a perfect weld.
Does Contact Tip Size Matter?
The size of the welding wires matters the most for the MIG contact tip. A welding wire is available in various sizes from 0.024-inches to 0.094-inches. They mainly vary in thickness.
For example, a 0.045-inch (1.2 mm) wire requires a 0.045-inch (1.2 mm) contact tip. It is mainly used for galvanized sheet metal.
Likewise, a 0.052-inch (1.3 mm) wire requires a 0.052-inch (1.3 mm) contact tip. This size is appropriate for plate steels with a medium portion of rust or mill scale.
Choosing the right MIG contact is important to reduce the probability of burn-backs and avoid an erratic arc caused by inconsistent electrical conductivity.
More importantly, you will have better control over inputting an ideal amount of raw material wire that comes into contact with the workpiece.
It will ensure good-quality arc starts, higher penetration, and increased weld quality. Hence, you will run your welding machine safely and dependably for a long time.
Last Words
When choosing the right MIG contact tip, consider the wire type, wire cast, and wire quality type. It will help you achieve a better overall welding result.
Hopefully, you got a clear idea of various MIG contact tip types and their characteristics and ideal usage.
Related Article
Sources
- americantorchtip.com/blog/everything-you-need-to-know-about-mig-contact-tips/
- earlbeck.com/welding-blog/what-is-a-welding-contact-tip