Mig contact tips are used in mig welding gun to prvide a conductive path for mig wire. They ensure the wire is in the right position in torch and also maintain right distance between wire & workpiece.
MIG contact tips are available in various sizes, from 0.024 to 0.094 inches. They are made of different materials. 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.
What Is MIG Contact Tip?
A MIG contact tip is an essential component of a MIG welder, which passes the welding current to the wire to produce the arc while passing through the bore
The contact tip plays a vital role in feeding the wire to the weld. Plus, a MIG welding gun contains a nozzle where the contact tip is located.
Why Is MIG Contact Tip Important?
A MIG contact tip has a significant impact on the welding process. The wire and contact tip must be matched to each other. Tips work as a medium to transfer current from mig welder to the mig wire. Without flowing current to the wire the arc won’t produce and no weld will be generated.
Its size, shape, and ID need to be compatible. 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 mus 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? What size to use?
The size of the welding wires matters the most for the MIG contact tip. A welding wire is available in various sizes from .024-inches to .094-inches. They mainly vary in their 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 burnbacks 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.
Types Of Contact Tips
MIG contact tips are available in various types based on their materials. Let’s learn about them one by one.
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 is higher than 55 S/m*. Also, its higher electrical conductivity ensures a fast, reliable, and non-destructive welding joint.
Manufacturers mainly use CDA C12200 (P deoxidized copper) grade copper for MIG contact tips. This type of tip is widely used for hand-held welding applications.
You can also use this standard copper welding contact tip for any welding projects requiring high wear characteristics and resistance to softening.
Due to its higher conductivity, you can achieve consistent wire feeding with minimal drag and fewer potential quality problems.
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 machinelike welding projects.
It comes in handy when you need an accurate TCP for achieving consistency and repeatability from part to part and maintaining a perfect welding position.
Besides, you can use this CuCrZr contact tip for a 100% duty cycle in welding to weld nonstop without any breaks.
In addition, it has 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
You can utilize this contact tip for the hot wire GTAW process to create yields with lower dilutions, low distortion, and improved quality.
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, ensure better arc starts, 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 properties at elevated temperatures to create this type of contact tip. That’s why its hardness level is 180.
The welding tip is ideal for use for a range of applications, such as welding consumables. It can endure up to 800°C (1472 °F) without decreasing the working life of the contact tip.
The heavy-duty silver-plated CuCrZr contact tip won’t get softer than the feed wire.
Hence, you won’t have to worry about problems like reduced conductivity, arc-start issues, contact tip burnback, 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 good 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.
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.