Welding Rods For Mild Steel – Your Essential Guide To Choosing
Selecting the right welding rods for mild steel is crucial for strong, clean welds. For general-purpose work, 6013 rods are forgiving and versatile, ideal for beginners and various positions. For critical structural joints needing higher strength, 7018 rods offer superior performance but require a dryer environment and more controlled technique.
Understanding rod classifications, electrode coatings, and amperage settings will significantly improve your welding results on mild steel projects.
When you’re standing in front of a welding supply store’s wall of welding rods, it can feel a bit overwhelming. You’ve got your welder set up, your safety gear is ready, and you’re itching to lay down a bead on that mild steel project. But which rod is the one?
Choosing the correct welding rod isn’t just about picking a random stick; it’s about ensuring your weld is strong, durable, and looks good too. The right electrode makes all the difference between a weld that holds up to the test of time and one that fails under pressure.
This guide is your ticket to demystifying welding rods for mild steel. We’ll break down what those numbers and letters mean, explore the most common types you’ll encounter, and help you pick the perfect rod for your next project, whether you’re fabricating a custom workbench or repairing a garden gate.
Understanding Welding Rod Classifications for Mild Steel
The American Welding Society (AWS) has a system for classifying welding electrodes, and it’s your best friend when picking out welding rods for mild steel. These classifications tell you a lot about the rod’s capabilities and how it performs.
The most common classification you’ll see for mild steel is the “E” followed by four or five digits, like E6013 or E7018. The “E” simply stands for electrode.
The first two digits (or three for five-digit numbers) indicate the minimum tensile strength of the deposited weld metal, measured in thousands of pounds per square inch (psi). So, an E60xx rod deposits metal with at least 60,000 psi tensile strength, while an E70xx rod deposits metal with at least 70,000 psi.
The third digit (or fourth for five-digit numbers) indicates the welding position the electrode is suitable for. A “1” means the rod can be used in all positions (flat, horizontal, vertical, and overhead). A “2” means it’s for flat and horizontal positions only.
The fourth digit (or fifth for five-digit numbers) describes the type of flux coating and the recommended electrical current. This is where things get interesting, as it dictates arc characteristics, penetration, and cleaning ability.
Common Welding Rods for Mild Steel: A Deep Dive
When you’re working with mild steel, which is the most common type of steel used in DIY projects, you’ll likely be reaching for a few go-to electrode types. Each has its strengths and ideal applications.
The All-Around Workhorse: E6013
Often called the “all-purpose” rod, the E6013 is incredibly forgiving and a fantastic choice for beginners. It’s known for its smooth, stable arc and relatively low spatter.
- Versatility: E6013 rods are designed for all-position welding, making them super adaptable for various projects. You can weld in flat, horizontal, vertical-up, and overhead positions with ease.
- Ease of Use: They strike an arc easily and maintain a stable puddle, which is a huge plus when you’re learning or working on less-than-ideal surfaces.
- Penetration: They offer medium penetration, which is usually sufficient for most common mild steel thicknesses found in home workshops.
- Current: E6013 rods can be used with both AC and DC (either polarity) welding machines. This flexibility is a big reason they are so popular.
- Applications: Great for general fabrication, repairs on farm equipment, light structural work, and anything where a decent-looking, reasonably strong weld is needed without extreme structural demands.
If you’re just starting out or need a rod that will perform reliably on a variety of tasks, you can’t go wrong with E6013.
The Strong Performer: E7018
When strength and structural integrity are paramount, the E7018 electrode is the champion. These rods are low-hydrogen electrodes, which is a fancy way of saying they produce welds that are less prone to cracking, especially in thicker materials or under stress.
- High Strength: As the name suggests, E7018 rods deposit weld metal with a minimum tensile strength of 70,000 psi, making them ideal for critical joints.
- Low Hydrogen: The flux coating on E7018 rods contains specific ingredients that prevent hydrogen from entering the weld pool. Hydrogen can cause brittle welds and cracks, so this is a significant advantage for structural applications.
- Smooth Beads: They produce very smooth, clean welds with minimal spatter and excellent slag removal. The slag peels away easily once the weld cools.
- All-Position Capability: Like the E6013, the E7018 is an all-position electrode.
- Current: E7018 rods are typically run on DC+ (Direct Current Electrode Positive), though some brands can run on AC. Always check the packaging.
- Considerations: E7018 rods are more sensitive to moisture. They need to be stored in a dry place, and if they get damp, they must be reconditioned in a special oven. They also require a more controlled welding technique than E6013, with a slightly tighter arc length.
For projects like building a sturdy trailer hitch, reinforcing a truck frame, or any application where the weld will be under significant load, E7018 is your go-to.
The Deep Penetrator: E6010 and E6011
These two electrodes are often grouped together because they offer deep penetration and are excellent for welding dirty, rusty, or painted metal. They are commonly used in pipe welding and general repair work where surface preparation might not be perfect.
- Deep Penetration: E6010 and E6011 rods have a forceful, driving arc that really digs into the base metal. This is great for getting good fusion on thicker materials or when you can’t grind away all the rust.
- All-Position: Both are all-position electrodes.
- E6010: This rod runs exclusively on DC+. It has a very forceful arc and is often favored by professional pipe welders for its ability to handle challenging conditions.
- E6011: This is the AC counterpart to the E6010. It offers similar deep penetration and performance but can be used with AC welding machines, making it more accessible for DIYers with AC welders.
- Arc Stability: The arc can be a bit “stiffer” or “cracklier” than E6013, and they tend to produce more spatter.
- Slag: The slag can be a bit harder to remove than with E6013 or E7018, and it’s important to ensure all slag is chipped away between passes on multi-pass welds.
If you’re tackling a rusty old tractor part or need to weld through some grime, an E6011 (for AC machines) or E6010 (for DC machines) might be your best bet.
Factors to Consider When Choosing Your Welding Rods
Beyond the basic classifications, several other factors will influence your choice of welding rods for mild steel. Thinking about these will help you make a more informed decision.
Your Welder Type and Power Output
The type of welding machine you have—AC, DC, or AC/DC—will significantly limit your rod choices.
- AC Welders: If you have an AC-only welder, you’ll be looking at rods like E6011 and E6013, which are designed to run on alternating current.
- DC Welders: DC welders offer more flexibility. You can run E6010, E7018 (DC+ is most common), and E6013 (DC or DC-). DC welding generally provides a more stable arc and better control for many applications.
- AC/DC Welders: These are the most versatile, allowing you to use almost any common mild steel rod. You can choose the rod best suited for the job and then select the appropriate current type.
Also, consider your welder’s amperage output. Thicker rods (e.g., 1/8-inch or 3.2mm) require more amperage than thinner rods (e.g., 3/32-inch or 2.4mm). Ensure your welder can provide enough power for the rod diameter you choose.
Material Thickness
The thickness of the mild steel you’re welding is a critical factor.
- Thin Material (e.g., 16-gauge to 1/8-inch): You’ll want to use thinner rods (like 1/16-inch, 5/64-inch, or 3/32-inch) to avoid burning through the metal. E6013 is often a good choice here due to its controllable arc.
- Medium Thickness (e.g., 1/8-inch to 1/4-inch): You can use a wider range of rods, including 3/32-inch and 1/8-inch. E6013 and E7018 are both excellent options.
- Thick Material (e.g., 1/4-inch and up): Thicker rods (like 1/8-inch or 5/32-inch) and rods with deeper penetration capabilities like E6010/E6011 or high-strength rods like E7018 are recommended. For very thick material, multiple passes might be necessary, and the choice of rod for each pass becomes important.
Welding Position
As we’ve touched on, different rods are rated for different welding positions.
- All-Position: E6013, E6011, and E7018 are all suitable for welding in any position.
- Flat/Horizontal Only: Rods like E7024 are designed for high-deposition welding in the flat and horizontal positions only. They produce a very smooth bead but aren’t versatile for other positions. These are less common for general DIY but might be found in production settings.
For most DIY projects, you’ll be working in various positions, so sticking with all-position rods like E6013 or E7018 is usually the most practical approach.
Environmental Conditions and Surface Preparation
The condition of the mild steel you’re welding matters.
- Clean Metal: For the best results and strongest welds, always aim for clean metal. This means grinding away rust, paint, oil, and mill scale. When working with clean metal, E7018 often provides superior weld quality and strength.
- Slightly Dirty or Rusty Metal: If you can’t achieve perfect surface prep, rods like E6010 and E6011 are more forgiving due to their aggressive arc and ability to burn through contaminants. However, it’s always best practice to clean the metal as much as possible.
- Moisture: E7018 rods are particularly sensitive to moisture. If you live in a humid environment, ensure your E7018 rods are stored in a sealed container, ideally with desiccant packs. If they’ve been exposed to humidity, they might need to be baked in a rod oven before use to remove absorbed moisture. E6013 and E6011 are generally less sensitive.
Best Practices for Using Welding Rods on Mild Steel
Once you’ve chosen your welding rods for mild steel, following some best practices will ensure your welds are strong and safe.
Electrode Storage
- Keep them Dry: Moisture is the enemy of welding electrodes, especially E7018. Store rods in a sealed, dry container. A dedicated rod oven is ideal for E7018 if you live in a humid climate or plan to use them frequently.
- Original Packaging: Keep rods in their original packaging until you’re ready to use them. This protects them from damage and contamination.
Surface Preparation
- Cleanliness is Key: Always grind away rust, paint, oil, grease, and any other contaminants from the joint area. A wire brush and angle grinder with a flap disc or grinding wheel are your best friends here.
- Beveling: For thicker materials (generally over 1/4 inch), beveling the edges of the joint creates a V-groove. This allows the weld to penetrate fully and fill the joint completely, creating a much stronger weld.
Amperage and Polarity Settings
- Consult the Rod Packaging: Every pack of welding rods will have recommended amperage and polarity settings based on the rod diameter. These are starting points.
- Fine-Tuning: You’ll need to adjust your settings based on your specific welder, the material thickness, and your welding position.
- Too hot (high amperage): Can cause burn-through, excessive spatter, and an unstable arc.
- Too cold (low amperage): Leads to poor penetration, a “ropey” looking bead, and potential for inclusions or lack of fusion.
- Polarity: Ensure you’re using the correct polarity (DC+ or DC-, AC) as specified for the rod. Incorrect polarity can lead to poor arc stability, reduced penetration, and increased spatter.
Welding Technique
- Arc Length: Maintain a consistent, short arc length. For most rods, holding the arc length roughly equal to the diameter of the electrode core wire is a good rule of thumb. A longer arc can lead to more spatter and porosity.
- Travel Speed: Move at a consistent speed. Too fast, and you won’t get enough penetration. Too slow, and you can overheat the base metal or create a large, blobby bead.
- Angle: Keep the electrode at a slight drag angle (trailing the direction of travel) for most rods like E6013 and E7018. E6010/E6011 might be run slightly more perpendicular or with a slight push depending on the application.
- Weave Patterns: For wider joints, a slight weave can be used, but avoid excessive side-to-side motion, which can cool the puddle too much. Straight stringer beads are often preferred for structural integrity.
Safety First!
- Personal Protective Equipment (PPE): Always wear a welding helmet with the correct shade lens, flame-resistant clothing (cotton or leather, no synthetics), sturdy leather gloves, and safety glasses.
- Ventilation: Weld in a well-ventilated area. Welding fumes can be harmful.
- Fire Hazards: Keep a fire extinguisher (rated for Class A, B, and C fires) nearby. Remove any flammable materials from the welding area.
Frequently Asked Questions About Welding Rods for Mild Steel
What is the most common welding rod for mild steel?
The E6013 is arguably the most common and versatile welding rod for mild steel, especially for DIY and general-purpose applications due to its ease of use and all-position capability.
Can I use any welding rod on mild steel?
While many rods are designed for mild steel, you need to match the rod to your welder’s capabilities (AC/DC) and the specific requirements of your project (strength, position, material condition).
How do I know which diameter welding rod to use?
The diameter of the welding rod you choose depends on the thickness of the mild steel you’re welding and the amperage output of your welder. Thinner rods are for thinner metal and lower amperages, while thicker rods are for thicker metal and higher amperages. Always check the rod packaging for recommended settings.
What’s the difference between E6013 and E7018?
The main differences lie in their strength, application, and handling. E6013 is more forgiving, easier to use for beginners, and good for general fabrication. E7018 offers higher tensile strength, is better for critical structural welds, but requires more careful storage and technique due to its low-hydrogen properties.
Do I need to keep welding rods dry?
Yes, especially E7018 rods. Moisture in the flux coating can introduce hydrogen into the weld, making it brittle and prone to cracking. Store them in a dry, sealed container.
Choosing the right welding rods for mild steel is a foundational skill for any metalworker or DIYer. By understanding the classifications, considering your project needs, and following best practices, you’ll be well on your way to laying down strong, reliable welds. Don’t be afraid to experiment with different rods on scrap pieces to get a feel for how they perform. Happy welding!
