Tungsten 101 – Choosing and Preparing Your Electrode for TIG welding carbon steel

Back to Basics: Choosing and Preparing Tungsten for TIG Welding Carbon Steel

 

TIG welding offers tight control and clean results — but only if your tungsten is selected and prepped  correctly. 

Your choice of tungsten, how you grind it, and how you maintain it can make a big difference . 

On this post, We are going to strip it down to the essentials: how to choose the right tungsten for carbon steel, how to prep it properly, and what mistakes to avoid.

✅ Which tungsten is best for carbon steel?

For TIG welding mild or carbon steel, you want a tungsten that holds a sharp point, starts easily, carries a lot of amperage, and runs a stable arc. Here are the top choices:

1️⃣ 2% Thoriated (Red Band)

• Type: EWTh-2
• Why it works: Excellent arc starts, good performance on DC.
• Downside: Slightly radioactive — some authorities say this is not a major risk in normal use, but always grind with proper ventilation and precautions. Can be used on both DC and AC but Does not perform very well as an all purpose tungsten for both steels and aluminum  

 

• 2️⃣ 2% Ceriated (Gray Band)
• Type: EWCe-2
• Why it works: Smooth arc starts, especially at low amperage.
• Good choice for thin carbon steel or or stainless and good for beginners practicing on thinner coupons.

3️⃣ 2% Lanthanated (Blue Band)

• Type: EWLa-2
• Why it works: Versatile, good for both AC and DC. High amp carrying capability.
• Pro tip: Lanthanated tungsten can be a great “universal” option if you also TIG aluminum and want to only stock one type.

⚙️ How to grind tungsten for carbon steel

For carbon steel, you're welding on DC electrode negative (DCEN) sometimes referred to as DC straight polarity — and that means you want a sharpened point, not a balled or rounded tip.

🔧 Steps to prep your tungsten:

1. Use a dedicated tungsten grinder or wheel
• Best practice is not to use the same wheel you grind carbon steel with (even though the risk of problems is pretty low.)
• Grind lengthwise (not across the tip)
• Grinding in the direction of the electrode length helps the arc stay focused and straight.
• Grinding sideways followed by a light finish grind lengthwise is also fine.

1. Taper the tip to about 2.5× the diameter or around 30 deg

• Example: For 3/32" tungsten, aim for a 1/4" long taper.
• The point should be sharp but not needle-thin.

1. Optional: Less taper for higher amperage ..or...Flat the tip slightly

• A small flat spot (like the thickness of a dime) at the end can help reduce tip erosion at very high amps. 

🧼 Keep it clean

• If you dip the tungsten in the puddle, stop and regrind — don’t keep welding with a contaminated tip.
• Store sharpened electrodes in a clean tube or case to avoid dirt or dust.

🔁 Tungsten size guide for TIG Welding carbon steel using DCEN

Material Thickness	Tungsten Size	Amperage Range
1/16" (1.6mm) or less	1/16"	20–80 amps
1/8" (3.2mm) plate	3/32"	70–150 amps
1/4" (6.4mm) plate	1/8"	120–250 amps

👆 Use this as a general guide— it is not always necessary to switch to smaller tungsten when making a few welds on thinner metal… there is a lot of overlap where a 3/32” or even a 1/8”  electrode can work fine even on thinner metal if sharpened correctly

See previous page on cleaning mill scale before tig welding

See next page on filler rod selection for carbon steels

Main index page on TIG Welding Basics for Carbon steels