TIG Welding Steel Tubing

How to TIG Weld Coped Tube joints

TIG welding techniques for Carbon steel tubes

TIG Welding 4130 Chromoly Tubes

 More videos on TIG welding Steel

Here’s a clear breakdown of the most commonly welded carbon steel tubing grades used in general fabrication and motorsports:

🔹 General Fabrication (structural, machinery, furniture, etc.)

1️⃣ A500 (ASTM A500 Grade B or C)

• Usage: Structural tubing, machine frames, supports, railings.
• Properties: Mild carbon steel; available in square, rectangular, and round sections; good weldability.
• Notes: Often used for its availability and price point.
• filler metal: ER70S2 or ER70S6

2️⃣ 1018

• Usage: Applications needing tighter dimensional tolerance, moderate strength, easy machining after welding.
• Properties: Low carbon steel, smooth finish, good weldability.
• filler metal: ER70S2 or ER70S6

3️⃣ 1020 / 1026 DOM (Drawn Over Mandrel)

• Usage: Where better surface finish, concentricity, and mechanical properties are required.
• Properties: Seamless-like quality; stronger and cleaner than A500.
• Notes: Often chosen when precision matters, though more expensive than A500.
• filler metal: ER70S2 or ER70S6

🔹 Motorsports and General Aviation (chassis, roll cages, suspension components)

1️⃣ 4130 Chromoly (Chromium-Molybdenum Alloy Steel)

• Usage: Roll cages, Fuselages, chassis, suspension links, control arms.
• Properties: Stronger and lighter than mild steel, weldable with proper technique (typically TIG or MIG with preheat for thicker sections).
• Notes: Preferred in high-performance motorsports and general aviation due to strength-to-weight ratio.
• filler metal: ER70S2 or ER70S6 OR ER80SD2

2️⃣ 1020 / 1026 DOM Tubing

• Usage: Alternative to 4130 in hobbyist or budget builds; used for cages, frames.
• Properties: More forgiving to weld than 4130; can be MIG or TIG welded with less concern for cracking.
• filler metal: ER70S2 or ER70S6

3️⃣ Mild Steel ERW (Electric Resistance Welded) Tubing (e.g., A513 Type 1)

• Usage: Lower-cost builds, off-road fabrication where rules allow. ( certain motorsports bodies do not permit for use on roll cages)
• Properties: Easy to weld, but not as strong as DOM or 4130.
• filler metal: ER70S2 or ER70S6

💡 Quick Notes

✅ 4130 Chromoly is the dominant choice for certain motorsports applications where weight and strength are critical.
✅ DOM 1020/1026 is often used in grassroots racing, off-road, and hot rods due to good strength, affordability, and weldability.
✅ A500 / mild steel is most common in general fabrication due to cost and ease of use.

All the grades described above can be TIG welded using 

• filler metal: ER70S2 or ER70S6

NASCAR requires DOM (Drawn Over Mandrel) tubing for chassis construction because it offers a reliable balance of strength, consistency, and weldability, which are critical for safety and performance in stock car racing. Let’s break down the reasons:

To get the best results, you need the right TIG cup for the application.

That does not mean every situation requires a different TIG cup.

There is a big difference in just getting by with something that works and having the best cup for the job.

As welders, we get thrown into the deep end of the pond sometimes and it helps to have an arsenal of TIG cups and hardware to choose from to get the best possible result.

The Weldmonger® TIG pro Kit is like a  Swiss army knife of TIG cup Kits with a cup for nearly every situation you might encounter.

The TIG pro kit has the most popular Furick cups along with large diameter gas lens cups and hardware.

One of the best things about a TIG kit like this is that you can be sure it all fits your TIG torch.

This Video Shows Tips and Techniques for How to TIG Weld Carbon Steel, Stainless, Aluminum, and Titanium

How to Identify what type TIG torch you have...( don't worry, there are only 2 main styles of TIG torches)

When it comes to TIG torch parts, there are only 2 main types of TIG torches...#17, 18, 26  are one type.  

And #9 and 20 are the other type

So all you need to do is take a look at your current TIG torch and see which collet body matches the photos above and then order either a kit for 17,18,26 style torch or a kit for #9 and 20 TIG torch.

TIG cups are sized by 1/16" increments so a #4 is 4/16" or 1/4" inside diameter.

A #4 tig cup is useful for welding at extremely low amperage and low argon flow rates...for saving argon gas when the welding supply is closed and  also for flash tack welding sheet metal.

A #5 is a favorite of a lot of tig welders for tig welding aluminum up to around .125" (3.2mm) thick

A #6 gas lens is a great all around cup for aluminum and so is a #7 or #8 when using a 1/8" tungsten.

A gas lens #6 cup will let you extend your tungsten much further than a standard collet body #6 cup. And sometimes you need to extend the tungsten to reach a weld.

If you weld stainless, 4130 chromoly, tool and die repair, or nickel alloys like inconel, a Jazzy 10 or Furick ceramic fupa 12 are both great choices.

We have made it easy for you with our high quality TIG cup Kits.

If you are still using the standard collet body cups that came with your TIG torch, you are probably not getting the best results possible.

The very first kit I would recommend to anyone using an air cooled 17 style torch is our Weldmonger® stubby gas lens kit

If you are still using the standard TIG cups and hardware that came with your machine or TIG torch, I can just about guarantee you will get better results if you upgrade to a weldmonger® stubby gas lens kit.