Question Mark
Experts answer frequently asked welding questions, helping welders improve equipment setup, troubleshoot performance issues, and better understand welding processes and consumables.
What Does the Number on my TIG Torch Nozzle Mean?
Most TIG torch nozzles – or cups, as they are commonly called – are marked with an identification number. This number represents the inside diameter of the cup in 1/16-inch increments. For example, a number 5 cup has a 5/16-inch inside diameter. Cups come in various sizes, shapes and configurations for many different applications.
Cup selection is important because we always want our welds to be free of atmospheric gas contamination. Selecting the proper cup depends on a couple factors, including the type of joint you are welding. A multilayer weld may require a smaller cup, one that can fit further down into the joint and a larger nozzle as the joint is filled to protect the weld. The type of material being welded can also have a bearing on the proper cup selection. For example, any of the nickel-based materials – such as stainless, titanium, Inconel – require a great deal more protection from the air, so larger cups are used to deliver more gas to the area.
The important thing to remember is that larger cups deliver a higher volume of gas. Keep in mind that this doesn’t work the same way as turning up the pressure with a small nozzle. Larger cups deliver more volume of gas, not more pressure.
Is Stick Welding as Versatile as Other Welding Processes?
Contrary to popular belief, stick welding – or shielded metal arc welding (SMAW) – is still a widely used and versatile process. When people think of stick welding, they usually think of pipeline welders, but various types of materials can be welded via the stick process. Stick electrodes are made in many different sizes, from 1/16-inch up to massive electrodes. The small electrodes can be used for thin materials – and even sheet metal, if the operator is sufficiently skilled. Electrodes are made for different steel types, castings, stainless steel and even aluminum.
However, stick welding does have drawbacks. It requires the added step of slag removal after the welding is finished, and it’s a slow process in comparison to MIG welding. But the advantage to stick welding in many applications is that it produces a clean, strong weld. The flux helps to clean the weld, but more importantly, it allows the weld to cool in the protection of the flux.
As always, much depends on the knowledge and skill level of the operator. In the right hands, that old stick welder sitting in the corner of the shop can do a lot of different types of welds on many different kinds of material.
I can’t seem to get my MIG Welder Dialed in. What Could be Causing the Difficulty?
When your welding machine performs well for many months, then suddenly becomes diffi cult to get dialed in, it’s usually due to a lack of maintenance. Welding machines are exposed to shop dirt, grinding dust (metal
particles) and in many cases, a lack of proper care. They require maintenance like any other piece of equipment.
It may be hard to believe, but the most common piece of equipment to cause a welding machine to be fi nicky is the contact tip. It can be that simple, and yet it is often overlooked. Remember that the contact tip is where the electrical connection is made to the electrode. The contact tip energizes the wire, and we know tight connections need to be made for electricity to work the way it’s supposed to. But contact tips will ultimately wear out, and then must be replaced. That’s why the tip is called a consumable. The contact tip can look fine in a quick visual inspection, but it can also be worn just enough to create a loose connection to the wire, which can create a variety of issues and problems.
In the end, there can be many reasons why you can’t dial in your welder correctly, but the contact tip is a good place to start.
Why are there so Many Different Sizes of Tungsten Electrodes?
Tungsten electrodes are manufactured in various diameters ranging from .40 of an inch up to ¼-inch for diff erent applications. If we follow the general rule of 1 amp per thousandths of an inch of material thickness, we can more easily understand what size tungsten to use. Each diameter of electrode has an amperage operating range, and these ranges typically overlap.
The thicker the material, the more amperage needed and the larger the electrode needed. For thin materials, a smaller tungsten will initiate the arc at lower amperages. The tungsten will maintain a more consistent arc at lower amperages, which gives the welder more control of the arc on thin materials.
Larger tungsten requires more amperage to ignite and maintain a smooth arc. The best general size tungsten for small shop applications is 3/32-inch. This size is ideal for welding up to the 200-amp range, and works well on thin materials too. If the tungsten is too small, it will continually burn away and constantly need to be sharpened. At that point, it’s time to move to the next larger size.
Keep in mind that your welds and welding projects will always go more smoothly if you take the time to do a little research and fi nd the most appropriate tungsten size for your application.