Lincoln Electric’s Anti-Seize™ thread design for contact tips and diffusers help to dissipate heat and extend service life.
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.
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.