Tig torch cups

[gearhead]

What's the general thoughts on the size of the tig torch cup openings. Currently I'm using a #5 with a 1/16th electrode. What does the number 4 or 6 ect offer above the others. Is there a general rule of thought on the electrode size and the size of the opening of the torch cup. I don't seem to have a contamination issue with any of the different cups I have been using.

[JonnyTIG]

Depending on the material being welded, the cup size may vary. I don't know if there is a general rule, but for instance, when you are cup walking on stainless or steel, you start with a smaller cup and graduate up in the sizes each pass to help 'roll over top' of the previous past. For free hand welding aluminum or ferous metals, I stick to one size of cup. With a 1/16" electrode, I usually use a 1/4" to 3/8" ID cup. I don't know the # sizes of cups so I can't help you there.

[Danny]

I believe the cups are measured in 10th's. like a #5 is 1/2". I am pretty sure thats how it works, feel free to correct me if I am wrong.
Back to the original question. I think you need to decide the cup # according to the weld and material. I am sure alot of this is personal choice. I tend to run smaller cups then others, unless I am welding aluminum, I then run a bigger (say 7) . It may be my opinion , but I always felt the extra gas around the weld area helped keep contamination down.

[glockdoc]

Also believe it has something to do with the amount of heat in proximity to the cup. If the cup is too small for the heat, it will start to erode away at the edges and/or break.

[FusionKing]

Kind'a crazy for me on the cup size thing.... I been using a 6 or a 7 for years with 3/32 or 1/8 but since I started working a "regular" job besides my own biz I've started using a 5 with 1/8th tungstan and tapered the tip down to about 1/16th. Burning on aluminum 1/8" to 3/16" thick all day in all types of joints both standing and sitting for 4 ten hour days!
I would never have done that on my own and looking at charts I see it's for like 1/16 tung but when you taper the tung. it helps. Using this setup allows for making a narrower bead and able to dig deep real quick. I have found on a 250 syncrowave setting almost all the way over on max penetration works best on the balance.
One thing is for sure I learned is wherever I go to work I always learn some new stuff and at my present job (ambulance body mfg) I had to get faster to keep up with the parts thrown at me and to get them to the guys waiting on my parts. I make all the doors and a normal ambulance has about ten of them...some more some less. I also just by default welded so much more in a production setting improved my tig welds from what I would have called above average to awesome.The pay sucks but it's sor'ta like being back in school so in a nutshell ...all those charts are great but nothing beats burning rod and asking questions (as you are doing gearhead) I hope that helps!

[fun4now]

GAS NOZZLES (Cups)

They are used to direct the shielding gas over the tungsten electrode and to cover the weld area with shielding gas. Nozzles are made from different materials. The most commonly are:

• Ceramics
• Metal-Jacked Ceramics
• Metal
• Fused-Quartz

Nozzles are identified by the size of the orifice (opening) by given number measured in 1/16” (1.6 mm) increments and by the length of the nozzle.

Example: A number 6 nozzle thus has a diameter of 3/8” (6 x 1/16 = 6/16” = 3/8” or 6 x 1.6 = 9.6mm).

Nozzle’s opening is selected according to:

• Amount of gas flow
• Weld joint type
• Accessibility of the weld area
• Welding position
• Tungsten electrode diameter

In general, a nozzle opening is about four times the electrode diameter.

there are ofcorse specilty aplications and cups as well as trailing cups and even some new stuff out that is like a steel plate with holes to alow gas flow for better trailing gas.
hope this is of some help.