What Do the Numbers on a Stick Welding Rod Mean Detailed Guide
When a welding rod is marked E6013 or E7018, those characters identify far more than a product name. They indicate the electrode type, weld strength, usable positions, and coating or current characteristics. Understanding the code helps a welder select a rod that matches the joint, base metal, and welding machine.
If you have ever wondered, what do the numbers on a stick welding rod mean, the answer is found in the AWS electrode classification. Each part of the marking has a specific purpose, although the final digit can vary slightly among electrode standards.
What the Rod Code Means
A common mild-steel stick electrode marking is E7018. Read from left to right:
- E means electrode.
- 70 means the weld metal has a minimum tensile strength of 70,000 pounds per square inch, or 70 ksi.
- 1 identifies the welding positions in which the electrode is classified for use.
- 8 identifies the coating type and the compatible welding current or polarity.
Therefore, E7018 is an electrode with 70 ksi minimum tensile strength, an all-position classification, and a low-hydrogen iron-powder coating designed for specific AC or DC operation.
Most commonly used carbon-steel rods follow this basic pattern:
E [tensile-strength digits] [position digit] [coating/current digit]
The code is not a direct setting for amperage. Rod diameter, joint design, material thickness, and the manufacturer’s label still determine the proper current range.
What the First Letter Means
The first letter, E, stands for electrode. It tells you that the classification applies to a covered stick electrode used in shielded metal arc welding, commonly called SMAW or stick welding.
The electrode’s covering creates shielding gas and slag as it burns and melts. That covering is also why the last digit matters: different coating formulas affect arc behavior, penetration, slag removal, moisture sensitivity, and the type of welding current the rod can use.
What the First Two Numbers Mean
The first two numbers after the letter indicate the minimum tensile strength of the deposited weld metal. The number is expressed in thousands of pounds per square inch.
| Rod marking | Strength portion | Minimum tensile strength |
|---|---|---|
| E6010 | 60 | 60,000 psi |
| E6013 | 60 | 60,000 psi |
| E7018 | 70 | 70,000 psi |
| E7024 | 70 | 70,000 psi |
The strength rating applies to the weld metal, not automatically to the base metal or the completed joint. A strong rod cannot compensate for inadequate joint preparation, poor technique, contamination, or an unsuitable welding procedure.
Some electrodes use a three-digit strength value in their classification rather than the familiar two-digit values. The complete AWS marking on the package should always be checked when the classification does not follow the common E60 or E70 pattern.
What the Third Number Means
The third character identifies the electrode’s approved welding position. The position code most often seen in common carbon-steel rods is 1, 2, or 3.
| Position digit | General meaning |
|---|---|
| 1 | All positions |
| 2 | Flat and horizontal fillet positions |
| 3 | Flat-position welding |
| 4 | Used in some classifications for flat, horizontal, overhead, and vertical-down welding |
Position markings can be affected by the exact electrode standard and classification. For that reason, the package or manufacturer’s data sheet takes priority over a simplified chart.
For example, E6010 and E7018 both contain the position digit 1, so both are classified for all-position welding. E7024 contains the digit 2, making it intended mainly for flat and horizontal fillet work rather than general all-position welding.
“All position” does not mean the rod produces identical results in every position. Vertical and overhead welding normally require different amperage, travel speed, arc length, and puddle control than flat welding.
What the Last Number Means
The final digit identifies the electrode covering and provides information about the current type and polarity for which the rod is designed. This is the part of the code that most directly changes the way the rod runs.
| Final digit | Typical coating or classification feature | Common current information |
|---|---|---|
| 0 | High-cellulose sodium | Usually DC electrode positive |
| 1 | High-cellulose potassium | Usually AC or DC electrode positive |
| 2 | High-titania sodium | Typically AC or DC electrode negative |
| 3 | High-titania potassium | Typically AC or DC, depending on the classification |
| 4 | Iron powder and titania | Commonly AC or DC |
| 5 | Low-hydrogen sodium | Usually DC electrode positive |
| 6 | Low-hydrogen potassium | Usually AC or DC electrode positive |
| 7 | Iron powder and iron oxide | Commonly AC or DC |
| 8 | Iron powder and low-hydrogen coating | Commonly AC or DC electrode positive |
This chart is a practical guide for common AWS carbon-steel electrodes, not a substitute for the specific rod manufacturer’s information. The final digit can include details beyond coating chemistry, and current recommendations should be confirmed on the package.
Examples of Common Rod Numbers
E6010
E6010 is a 60 ksi, all-position electrode with a high-cellulose sodium coating. It is commonly associated with deep penetration and DC electrode-positive operation. The coating produces a forceful arc and a fast-freezing slag, characteristics that support root passes and work in difficult positions.
E6011
E6011 also has a 60 ksi strength rating and an all-position classification. Its high-cellulose potassium coating allows it to operate on AC as well as DC electrode positive. It is often selected when an AC-only welding machine must handle work that calls for a penetrating, all-position rod.
E6013
E6013 is a 60 ksi electrode with a rutile-type coating and a relatively smooth, easy-to-control arc. It is commonly available for AC and DC use. The classification is widely used for general fabrication and lighter work, but the exact position capability and current range should still be verified on the package.
E7018
E7018 is a 70 ksi, all-position, low-hydrogen electrode with an iron-powder coating. The low-hydrogen designation is important because moisture control and storage affect performance. A damp or improperly stored low-hydrogen electrode may not meet the intended hydrogen-control requirements.
E7024
E7024 is a 70 ksi electrode with an iron-powder coating intended primarily for flat and horizontal fillet welding. Its coating can produce a high deposition rate, but its position digit makes it unsuitable as a general replacement for an all-position rod.
How to Use the Numbers When Choosing a Rod
Read the complete classification before choosing an electrode. Start by matching the rod’s strength level to the welding procedure or base-metal requirements. Next, check the position digit to make sure the electrode is suitable for flat, horizontal, vertical, or overhead work.
Then verify the last digit against the welding machine. An AC-only machine cannot use every DC-only electrode correctly. A DC machine also requires attention to polarity, because electrode-positive and electrode-negative settings change penetration and arc behavior.
Finally, match the rod diameter to the material thickness and joint. The classification tells you what the electrode is designed to do, but it does not tell you whether a 1/8-inch or 3/32-inch rod is appropriate for a particular joint. The amperage range printed on the package is the correct starting reference.
Never identify a rod by its appearance alone. Similar-looking electrodes can have different coatings, current requirements, and strength classifications.
Numbers Beyond the Main Classification
Some stick rods include additional letters and numbers after the main classification, often separated by a hyphen. These markings can identify alloy content, low-carbon composition, hydrogen limits, impact-test requirements, or other properties.
For example, an added L may indicate a low-carbon version in certain stainless-steel classifications. A marking such as H4 or H8 can identify a diffusible-hydrogen limit when that designation applies. Stainless-steel electrodes also use different classification systems, such as E308L-16, so the carbon-steel E6010/E7018 pattern should not be applied blindly to every stick rod.
The full classification on the rod container is the authoritative identification. If a marking is unfamiliar, consult the applicable AWS specification or the manufacturer’s technical data rather than guessing from one digit.
Common Mistakes in Reading Rod Numbers
- Reading 70 as a recommended amperage: it means 70,000 psi minimum tensile strength, not 70 amps.
- Assuming every rod is all-position: the position digit must be checked.
- Ignoring the final digit: coating and current compatibility affect whether the rod will run correctly.
- Treating strength as the only selection factor: position, polarity, coating, diameter, and procedure requirements also matter.
- Overlooking storage requirements: low-hydrogen electrodes require particular protection from moisture.
FAQ
What does E6013 mean on a welding rod?
E6013 identifies a 60 ksi electrode with a position classification represented by 1 and a final coating/current classification represented by 3. The exact current options and position guidance should be confirmed on the manufacturer’s label.
What does E7018 mean?
E7018 means a 70 ksi, all-position electrode with an iron-powder, low-hydrogen coating classification. It is commonly used with AC or DC electrode-positive welding, subject to the specific product instructions.
Does the number on a welding rod tell me
No. The classification does not give a single amperage setting. Use the rod diameter and the amperage range printed on the package, then adjust for position, joint design, and welding conditions.
What does the last number on a stick welding rod
The last number generally identifies the electrode coating and the compatible current type or polarity. For example, the 8 in E7018 indicates an iron-powder, low-hydrogen classification.
What does the 1 mean in E6010 or E7018?
The 1 is the position digit. In these common classifications, it indicates that the electrode is classified for welding in all positions.
Can I use any rod with an AC welder?
No. The final digit and the manufacturer’s specifications identify whether a rod is suitable for AC. Some electrodes are designed mainly for DC, while others can operate on AC, DC electrode positive, or both.
Conclusion
Understanding what do the numbers on a stick welding rod mean starts with separating the code into its parts: electrode type, weld-metal strength, welding position, and coating/current classification. Once those details are matched to the joint, machine, polarity, and rod diameter, the marking becomes a practical selection guide rather than a confusing string of numbers.
