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Welding Tip Alloy Comparison:

Standard DHP (Regular Copper) - world wide standard excellent general purpose.

CrZr - (Cr-Chromium Zr-Zirconium) a very hard alloy, has been around for years made for stainless steel and stiff, high column strength or abrasive wires such as Flux cored / Metal cored. If you are attempting to get a sure start you need to choose the best alloy, whether for electrical or physical wear. The next reason a tip wears is due to heat. As the tip heats from the welding process the properties of the alloys start to break down. The ability of the tip to dissipate the heat (thermal conductivity) will aid in keeping the tip cooler. The (electrical resistance) of the alloy is also inversely proportional to the electrical conductivity. As we need a sure start and are attempting to jump the gap from the contact tip to wire, these two factors play a critical role--if the tip has higher conductivity of electricity it will transfer the current easier (or with less resistance) which will also cause the tip to run cooler. Resistance equals heat. The additional benefit to higher conductivity is that the arc transfer from the tip to the wire is easier. Easier arc transfer means a superior sure start and less arc failure or wire burn back, sputtering and spatter.

There are 2 main reasons a welding tip wears:

1. Common physical wear or abrasion, if you were to place a tip on the wire before the feeder with NO electrical contact, that tip would eventually wear completely through.
2. Electrical erosion is similar to the brushes on an electrical motor or the spark jumping across the gap on a spark plug. For example, if the wire is traveling through the Contact tip at 300 IPM the electricity has to jump across from the copper tip to the Mig wire (Hence the name "Contact Tip"). The inside bore of the tip and the welding wire are in constant electrical arcing as this process is happening. Electrical erosion is melting of the welding tip ID.

Make sure the gun tip isn't worn out or that weld spatter is not on the tip near the exit hole. The contact tip in the gun should be perfectly round and just a few thousandths larger than the wire itself. Worn tips are typically oval and can cause an erratic arc from the random electrical connection and physical movement of the wire inside the worn tip. Genuine D/F Machine Specialties contact tips are precisely made from a wear-resistant copper alloy for superior welding performance. If the contact tip enters the molten weld pool, it should be immediately replaced. For most casual welders, a good rule of thumb to assure high quality welding is to change the tip after ever 100 lbs. of wire. Another point to remember about contact tips is that they should always be threaded completely into the gas diffuser and tightened prior to welding to give a smooth flow of welding current.

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