E6013 vs E7018: Choosing Basic Welding Rods

Understanding the Differences Between E6013 and E7018 Basic Welding Rods for Optimal Performance

Selecting the appropriate welding electrode is a foundational decision that impacts weld quality, efficiency, and project integrity. For many mild steel applications, especially within general fabrication, maintenance, and structural work, two specific types of welding materials stand out: E6013 and E7018. These electrodes are frequently chosen by both novice welders and experienced procurement teams due to their versatility and distinct characteristics. This guide aims to provide a comprehensive comparison, detailing their properties, ideal applications, and critical considerations for making the right choice for your specific needs.

At Oldwelders, we understand the importance of reliable and high-performance welding consumables. As an ISO 9001 certified manufacturer, we are committed to delivering products that meet stringent quality standards. Our commitment to quality begins with the raw materials for our welding fluxes and electrodes, utilizing excellent dolomite, bauxite, cryolite, silica, and fluorine ore, melted at 2000 °C to guarantee superior electrode coatings. This meticulous process ensures that our welding rods consistently deliver the performance expected by our industrial clients.

Decoding AWS Electrode Classifications

Before diving into the specifics of E6013 and E7018, it is crucial to understand the American Welding Society (AWS) electrode classification system. This system provides a standardized method for identifying the properties and intended uses of various electrodes, ensuring consistency and reliability across the industry. Each digit or letter in the classification holds specific meaning:

• E: Signifies an electrode for arc welding.
• First Two Digits (e.g., 60 or 70): Indicate the minimum tensile strength of the deposited weld metal in thousands of pounds per square inch (psi). For example, E6013 offers a minimum of 60,000 psi, while E7018 offers 70,000 psi.
• Third Digit (e.g., 1): Denotes the welding positions in which the electrode can be used.
  • 1: All positions (flat, horizontal, vertical, overhead)
  • 2: Flat and horizontal positions only
  • 4: Flat, horizontal, overhead, and vertical-down positions
• Fourth Digit (e.g., 3 or 8): Specifies the type of flux coating and the suitable welding current (AC, DC+, DC-). This digit is particularly important as it dictates the electrode's operating characteristics, penetration, and slag properties.

Understanding this classification system is the first step toward informed electrode selection, allowing welders and purchasers to quickly grasp an electrode's fundamental capabilities.

E6013 Basic Welding Rod: Characteristics and Applications

The E6013 electrode is often referred to as a "general-purpose" or "all-position" rod, making it a popular choice for a wide range of mild steel applications. Its versatility stems from its unique flux coating and operational characteristics.

Key Characteristics of E6013

• Flux Coating: E6013 electrodes have a high titania (rutile) potassium type flux coating. This coating produces a soft, stable arc with minimal spatter and a moderately fluid slag that is generally easy to remove.
• Arc Action: It provides a smooth, stable arc that is easy to strike and re-strike, making it user-friendly for beginners and suitable for intermittent welding.
• Welding Positions: Classified for all-position welding (flat, horizontal, vertical-up, vertical-down, overhead), which contributes significantly to its versatility.
• Penetration: Offers shallow to medium penetration, which is ideal for thin materials or situations where burn-through is a concern.
• Appearance: Known for producing smooth, clean, and aesthetically pleasing weld beads with a finely rippled appearance. This makes it a preferred choice for applications where cosmetic finish is important.
• Current Type: Can be used with both AC and DC welding machines, offering flexibility in equipment choice. This adaptability makes it suitable for various welding machine setups, including many arc welding machine models.
• Tensile Strength: Provides a minimum tensile strength of 60,000 psi.

Typical Applications for E6013

E6013 is excellent for:

• Sheet metal fabrication
• Light structural work
• General repair and maintenance
• Ornamental ironwork
• Tack welding
• Bridge work and general construction (non-critical joints)
• Projects where cosmetic appearance is prioritized.

Its ease of use and ability to perform well on contaminated or poorly prepared surfaces (within reason) make it a go-to for many general welding tasks. Our production capacity, with a plant covering an area of 1000 square meters and six production lines, allows us to supply up to 100 tons of high-quality welding rods and submerged arc welding flux hj431 daily, ensuring consistent supply for these common demands.

E7018 Basic Welding Rod: Characteristics and Applications

The E7018 electrode is a heavy-duty, low-hydrogen rod designed for critical applications requiring high strength, ductility, and superior weld integrity. It is often considered the workhorse of structural welding.

Key Characteristics of E7018

• Flux Coating: Features a low-hydrogen iron powder flux coating. The low-hydrogen characteristic is paramount, as it significantly reduces the risk of hydrogen-induced cracking, especially in high-strength steels or thick sections. This coating also contains iron powder, which increases deposition rates.
• Arc Action: Produces a smooth, quiet, and stable arc with moderate penetration. It can be slightly more challenging to strike an arc compared to E6013 due to its low-hydrogen properties, but it maintains a consistent arc once established.
• Welding Positions: Classified for all-position welding, though it is most commonly used in flat and horizontal positions for high deposition rates.
• Penetration: Provides medium penetration, creating strong, deep fusion.
• Appearance: Delivers flat to slightly convex weld beads with a fine ripple, offering excellent mechanical properties and a clean, solid appearance.
• Current Type: Primarily used with DC+ (Direct Current Electrode Positive) for optimal performance, though some variations can be used with AC.
• Tensile Strength: Offers a minimum tensile strength of 70,000 psi, along with excellent ductility and impact strength.
• Crack Resistance: Its low-hydrogen nature makes it highly resistant to hydrogen embrittlement and cracking, which is crucial for critical welds.
• X-ray Quality: Often produces X-ray quality welds, indicating excellent internal soundness and minimal porosity.

Typical Applications for E7018

E7018 is indispensable for:

• Heavy structural steel fabrication
• High-pressure piping and pressure vessels
• Shipbuilding and offshore structures
• Power generation equipment
• Heavy equipment repair
• Applications involving high-strength steels
• Any job where weld integrity, strength, and resistance to cracking are paramount.

For industrial partners requiring robust solutions, Oldwelders' manufacturing capabilities ensure a steady supply of high-grade welding consumables. Our typical lead time of 30 days and a minimum order quantity of 1 ton are designed to meet the demands of large-scale projects for clients in markets such as Brazil, Thailand, Australia, and Malaysia.

Key Differences: E6013 vs. E7018

While both E6013 and E7018 are versatile electrodes for mild steel, their distinct characteristics lead to different ideal applications. Understanding these differences is vital for optimal weld performance and project success.

Flux Composition and Hydrogen Content

The primary distinguishing factor lies in their flux coatings. E6013 features a rutile (titania) coating, making it easy to use and providing a smooth, stable arc. However, it is not a low-hydrogen electrode, meaning it can introduce more hydrogen into the weld metal, increasing the risk of cracking in critical applications. E7018, conversely, has a low-hydrogen iron powder coating specifically designed to minimize hydrogen entrapment, which is crucial for preventing delayed cracking in high-strength steels and thick sections. This makes E7018 the preferred choice for structural welds and applications requiring high integrity.

Mechanical Properties and Weld Strength

E7018 boasts superior mechanical properties, offering a higher tensile strength (70,000 psi minimum) and exceptional ductility and impact strength compared to E6013 (60,000 psi minimum). Welds made with E7018 are typically more robust, less prone to cracking under stress, and are often X-ray quality, making them suitable for critical load-bearing structures and pressure vessels. E6013 welds are adequate for general fabrication but do not offer the same level of structural integrity or resistance to cracking.

Ease of Use and Arc Characteristics

E6013 is renowned for its user-friendliness. It offers a soft, stable arc that is easy to strike and maintain, making it ideal for beginners or situations requiring intermittent welding. Its slag is generally easy to remove. E7018, while still manageable, requires a slightly more experienced hand. Its arc can be a bit more "stiff," and striking it can be trickier due to its low-hydrogen coating, which needs to be kept dry. The slag from E7018 is typically heavier and may require more effort to remove, but it provides excellent protection for the cooling weld metal.

Penetration and Weld Profile

E6013 provides shallow to medium penetration, which is advantageous for welding thinner materials without excessive burn-through. It produces a smooth, aesthetically pleasing bead. E7018 delivers medium to deep penetration, creating a strong, robust fusion zone, essential for thick materials and structural joints. The weld bead from E7018 is typically flatter to slightly convex, indicating good fill and strength.

Moisture Sensitivity

E7018 electrodes are highly sensitive to moisture absorption. Their low-hydrogen properties are compromised if the flux coating absorbs moisture from the atmosphere. Therefore, E7018 rods must be stored in specialized electrode ovens or sealed containers to maintain their integrity. E6013 is much less sensitive to moisture, although proper storage is always recommended for any welding consumable.

Choosing the Right Basic Welding Rod for Your Project

The decision between E6013 and E7018 hinges on several factors related to your specific welding project:

1. Application and Criticality: For general fabrication, cosmetic welds, or light repairs where high strength and crack resistance are not paramount, E6013 is often the more economical and easier choice. For structural welds, pressure vessels, heavy equipment, or any application where weld integrity is critical, E7018 is the unequivocal choice due to its superior mechanical properties and low-hydrogen characteristics.
2. Material Thickness and Type: E6013 performs well on thin to medium-gauge mild steel. E7018 is better suited for thicker sections of mild steel and high-strength low-alloy steels where its deeper penetration and crack resistance are beneficial.
3. Welder Skill Level: Beginners will generally find E6013 more forgiving and easier to master due to its stable arc and smooth operation. Experienced welders or those working on critical applications will be accustomed to the demands of E7018.
4. Equipment and Current Type: Both rods can be used with AC current, but E7018 performs optimally with DC+. Ensure your mig-mag-tig welding machine or other welding machine is capable of providing the recommended current type for the chosen electrode.
5. Storage Facilities: If you lack proper storage for low-hydrogen electrodes (e.g., heated ovens), E6013 might be a safer choice to avoid potential weld defects caused by moisture absorption in E7018.

At Oldwelders, we pride ourselves on being a knowledgeable partner in your welding operations. Our extensive range of welding consumables, including various types of welding rods, ensures that you can find the precise solution for your industrial needs. From the raw materials melted at 2000 °C for our flux products to our expansive 1000-square-meter facility with six production lines, every step is geared towards supplying 100 tons a day of superior quality products to our global clientele.

Conclusion

The choice between an E6013 and an E7018 basic welding rod is a critical decision that directly impacts the quality and performance of your welds. While E6013 offers ease of use and good cosmetic appearance for general-purpose applications, E7018 provides superior strength, ductility, and crack resistance essential for critical structural work. By understanding the distinct characteristics and ideal applications of each, welders and procurement professionals can make informed decisions that ensure safety, efficiency, and the long-term integrity of their projects.

Oldwelders is dedicated to supporting your welding endeavors with high-quality consumables and expert knowledge. Our ISO 9001 certification underscores our commitment to excellence, and our capacity to handle orders from a minimum of 1 ton with a 30-day lead time ensures we can meet the demands of growing markets in Brazil, Thailand, Australia, and Malaysia. For all your welding rod, wire, and welding fluxes needs, Oldwelders is your trusted partner.