TIG Torch Cup Size

by Russ
(Concord, NC)

How do you determine the best cup size. I started with a #7 as it came with the torch. I am now trying #4. I am using 3/32" tungsten and welding 1/8" steel. Can I cut back on the gas with a smaller cup?

-------------------------------------------------

When you are working by yourself and paying for your gas, one of the pluses to using a small cup is that you can set the flowmeter low and use less gas.

if i am welding 1/8" or thicker, i often use a 4 or 5 cup and only 10-12 cfh and it works fine on carbon steel.

the size cup is largely determined by accessibility to the weld and material type.

for example, titanium requires an extremely large cup because it cant tolerate oxidation of the weld pool at all.

stainless steel is helped out by a large cup too but it is not always necessary ...again, wire brushing can restore some luster.

Carbon steel is not harmed by a little oxidation and can be wire brushed shiny after welding so a small cup just saves gas and still works.

sometimes you need to get the tungsten down in a steep bevel or hole and a small cup is needed.

there are lots of other examples too many to list.
I am planning a video soon on examples of where to use what cup....but until then, just experiment and use common sense and you will probably figure out a lot on your own.

regards,

jody