ER70S-6 vs. ER70S-G MIG Welding Wires

What is the primary difference between ER70S-6 and ER70S-G MIG welding wires?

The fundamental distinction between **ER70S-6** and **ER70S-G** gas-shielded MIG welding wires lies in their specific chemical compositions and, consequently, their standardization.
       **ER70S-6** is a highly standardized and widely recognized **mild steel welding wire** with a specific and well-defined range of silicon (Si) and manganese (Mn) content. In contrast, **ER70S-G** is a general classification for various "as-agreed" or custom-formulated wires that meet the basic mechanical property requirements of an ER70S class but do not adhere to the precise chemical composition ranges of other defined ER70S subclasses like -2, -3, or -6.

What are the typical applications for ER70S-6 welding wire?

**ER70S-6 filler metal** is considered the workhorse of MIG welding for mild and low-alloy steels.
       Its robust deoxidizing properties, thanks to higher levels of silicon and manganese, make it excellent for welding on mill scale, rust, or other contaminated surfaces. Common applications include general fabrication, automotive repair, structural steel, pipe welding, and just about any project involving carbon steel where good bead appearance and minimal porosity are desired. It’s an incredibly versatile **welding consumable**.

What are the typical applications for ER70S-G welding wire?

**ER70S-G welding wire** is used in a more specific, or sometimes proprietary, range of applications.
       Because its exact chemical composition is not standardized by organizations like AWS (American Welding Society) beyond the basic "70S" mechanical properties, it often represents wires formulated for particular industrial processes, specific base metal combinations, or unique performance characteristics as agreed upon between the manufacturer and the user.
       You might encounter it in specialized manufacturing lines or for applications requiring a custom blend of properties that aren't met by standard ER70S classifications.

How do their deoxidizer levels compare?

**ER70S-6** contains higher levels of silicon and manganese, which act as powerful deoxidizers during the welding process.
       These elements effectively scavenge oxygen, preventing porosity and promoting cleaner, stronger welds, especially on less-than-perfectly clean surfaces. The **ER70S-G** classification does not specify deoxidizer levels; they vary based on the specific manufacturer's formulation, but they might not be as consistently high as in ER70S-6.

Which wire offers better tolerance to contaminated surfaces?

**ER70S-6** unequivocally offers superior tolerance to mill scale, rust, and other surface contaminants.
       Its rich deoxidizer content is designed to handle these impurities, resulting in more consistent and sound welds even when the base metal isn't perfectly clean. This makes **ER70S-6** a preferred choice in less controlled environments or for repair work where extensive cleaning isn't feasible.

Is ER70S-G a recognized AWS classification?

Yes, **ER70S-G** is an AWS classification, but it's a "general" or "unspecified" one.
       Unlike ER70S-6 (which has specific chemistry requirements under AWS A5.18), the "G" merely signifies that the wire meets the minimum mechanical property requirements (70 ksi tensile strength) for a mild steel electrode, but its chemical composition is left to the manufacturer's discretion and the agreement with the purchaser.
       Therefore, an **ER70S-G welding wire** from one manufacturer might have a slightly different chemical makeup than an ER70S-G from another, as long as it hits the mechanical properties.

When should I choose ER70S-6 over ER70S-G?

You should almost always choose **ER70S-6** for general-purpose MIG welding of mild steel.
       It's a proven, consistent, and highly reliable **welding wire** that offers excellent arc stability, good wetting characteristics, strong mechanical properties, and superior tolerance for various surface conditions. It's the standard for most workshops and fabrication settings due to its versatility and predictable performance.

When should I choose ER70S-G over ER70S-6?

You would typically only choose **ER70S-G** if a specific application or process dictates it, usually in industrial settings where a particular manufacturer has developed a custom wire.
       This might be due to very specific requirements for bead appearance, controlled penetration, or compatibility with a unique robotic welding setup. Unless you have a clear reason and specification for **ER70S-G**, it's generally best to stick with the more standardized and widely understood **ER70S-6**.

Does the choice of shielding gas differ between the two?

No, both **ER70S-6** and **ER70S-G** are designed to be used with standard MIG welding shielding gases, primarily 75% Argon / 25% CO2 (C25) or 100% CO2.
       The choice of shielding gas will depend more on the specific application and desired weld characteristics (e.g., penetration, spatter) than on the subtle differences between these two wire classifications.