Lincoln Electric’s Anti-Seize™ thread design for contact tips and diffusers help to dissipate heat and extend service life.
Copper Plus™ design contact tips add more mass to withstand more heat.
Select a gun with a full group of consumables, including various nozzles, like this extended version for tight spaces.
Step Two: Examining the expendable parts options
After considering amperage and duty cycle, examine a gun’s expendable parts. These components will degrade over time due to heat, spatter and wear during normal welding operations, so their lifespan affects the cost of gun ownership over time. Parts that last longer tend to keep costs down.
When battling elements like heat and wear, attention to detail in design can make all the difference. First, you might start by closely examining the thread design of the contact tips and diffusers. For best performance, select guns with Anti-Seize™ tips and diffusers, like those in the Magnum® PRO line from Lincoln Electric. Anti-Seize tips have threads with a flattened profile, increasing the cross-section where heat typically concentrates and tips tend to fail. This technology leads to reduced melting, fusion and seizing and extends contact tip service life. This characteristic helps to reduce both expendable part and labor costs, while increasing a welder’s time with a usable arc.
Next, consider the mass of the expendable parts. Remember, within reason, the larger the contact tip, the more heat it can withstand over long periods of time, giving it better heat deflection and longer life. Try to choose contact tips from a manufacturer that offers contact tips with a larger mass; for instance, Lincoln Electric provides contact tips that contain up to 40 percent more mass than other welding equipment suppliers.
Third, think about the type of alloy used in the contact tip, as it affects both the heat resistance and wear resistance. For example, when welding wire is fed through the tip, the hole can become elongated or misshapen over time if the material doesn’t withstand heat or wear well, resulting in improper electrical contact and welding issues caused by a wandering arc, discontinuities caused by dropouts and other issues. While many contact tips are made from various types of copper, some manufacturers have begun to market designs containing harder materials. These harder materials can withstand greater heat, last longer and resist elongation or wear at the contact tip.
Welders should also consider their application when selecting the proper nozzle. There are many different nozzle types, shapes and sizes and choosing the best match for the application can make a big difference in performance. For instance, if welding in a tight space, use a nozzle that is longer and more tapered, as the conical shape allows for easier accessibility into tight joints. In addition, some manufacturers, like Lincoln Electric, offer expendables that position the contact tips slightly outside of the nozzle to allow even greater access to tight areas.
Think about the rating of the expendable parts, as well. Those with higher amperage are larger in size and mass, meaning they withstand more heat and have a longer life, but their size may make them difficult to use in tight spaces. Again, don’t choose a higher amperage rating than is necessary for your expendable parts.
Flexibility of the expendable parts is also key – many gun manufacturers have different front end expendable parts for each gun model or group, requiring a greater amount of inventory and organization on the part of the welder. For ease of use, it’s best to select a gun manufacturer that provides fewer sets of expendable parts that can be used across all gun models, as is the case with the Lincoln Electric Magnum® PRO line. This single-source approach makes it simpler to manage shop inventory – there are fewer contact tip, nozzle and diffuser parts to track, understand, stock and order – and handling fewer parts also helps prevent operator error, as using the wrong expendable parts for a gun could result in poorer welding results, increased costs and potential rework. Finally, while many companies focus on the cost of the actual gun when making a purchase, it’s also critical to consider the cost of the gun’s front end expendable or consumable parts, as they comprise the bulk of the gun cost on an annual basis. Since most manufacturers have variability within the product range, select a manufacturer that provides expendables with long life and compatibility with all gun models for the greatest cost savings.