Welding Rods Explained
Whether you’re just starting out in welding or refining your technique, understanding the tools of the trade is key.
Among the most essential components are welding rods.
This equipment plays a vital role in creating strong, lasting metal joints.
From the coatings that line their surface to the colours that distinguish one type from another, welding rods come with a lot to unpack.
This guide breaks down the basics in clear terms, helping you explore the different types, how they’re used, and what those numbers and colours actually mean.
Key Takeaways
- Consumable vs non-consumable: Stick (SMAW) and MIG welding use consumable rods (they melt into the weld), whereas TIG welding uses non-consumable tungsten electrodes plus a separate filler rod.
- Rod materials: There are electrodes for many base metals, and each are designed to match the metal being welded.
- AWS codes: Electrode codes convey properties. The “E” means electrode. The first digits are tensile strength. The next digit(s) show welding position. The final digit(s) indicate coating and current.
- Tungsten colours: TIG tungsten electrodes are colour-coded by alloy. For instance, red tips are 2% thoriated tungsten, white tips are zirconiated, blue are lanthanated, and grey are ceriated.
- Choosing rods: Select a rod to match the base metal and weld requirements. The rod’s alloy, strength and code must suit the parent metal and weld position.
- Storage: Keep electrodes dry. Low-hydrogen rods must be stored in a rod oven to prevent moisture pickup.
What are Welding Rods?
Welding rods (electrodes) are metal sticks used in welding.
They conduct electrical current and create the welding arc.
In many processes (stick welding, for example), the rod melts and becomes the filler material that joins the metals.
These rods are often flux-coated, which helps stabilise the arc and protect the molten metal.
As the rod burns, the flux forms a slag that shields and cleans the weld.
Welding rods come in different forms.
In stick welding, you hold individual flux-coated rods.
In MIG welding, a continuous bare metal wire feeds as the electrode.
In TIG welding, the tungsten rod does not melt.
Instead, it provides the heat while you manually add a separate filler rod.
In all cases, the electrode (or rod) plays a key role in carrying current and adding material to the joint.
Understanding what a welding rod is also means recognising its classification.
Under AWS (American Welding Society) standards, stick electrodes are given codes (like E7018) that tell you their alloy, strength, position suitability, and coating.
In practice, a welder selects a rod with the right chemistry and coating for the base metal and welding method in use.
Differences Between Consumable vs Non-Consumable Welding Rods
Welding electrodes fall into two main categories: consumable and non-consumable.
Consumable Welding Rods/Electrodes
Consumable welding rods/electrodes melt during welding and become part of the weld.
Stick (arc) welding rods and MIG wire are consumable.
They have lower melting points and usually include flux.
As the electrode melts, it provides filler metal to the joint.
For example, a stick electrode in MIG or shielded metal-arc welding (SMAW) is made of steel and filler material.
Because it melts completely into the weld, it is called consumable.
The flux coating on a consumable stick electrode also vaporises to form shielding gas and slag.
Non-consumable Welding Rods/Electrodes
Non-consumable welding rods/electrodes do not melt into the joint.
The classic example is the tungsten electrode used in TIG welding.
Tungsten has a very high melting point, so the electrode stays intact, acting only as a heat source.
In non-consumable processes, a separate filler rod (if needed) is added manually.
For instance, in TIG welding you strike the arc with a tungsten rod, then feed a steel or aluminium filler rod into the weld pool.
The tungsten electrode itself is not consumed.
Consumable vs Non-consumable Welding Rods/Electrodes
The choice between consumable vs non-consumable depends on the process and requirements.
Consumable electrodes carry the weld metal and shielding within one wire, offering fast deposition.
Non-consumable electrodes provide a very stable arc and clean welds, since the filler is separate and cleaner.
Different Welding Rod Metals
Welding rods are made of many metals or alloys to match the base material being welded.
The most common filler is carbon steel, but there are rods for stainless steel, cast iron, aluminium, and more.
Below are some typical examples:
Carbon Steel Welding Rods/Electrodes
These stick electrodes (like E6013, E7018) are made of mild or low-alloy steel.
They match common structural steels and are used for general welding.
Rods for steel are often classified by tensile strength.
Steel rods have coatings (cellulosic, rutile, low-hydrogen) to aid the welding process.
They are the most widely used filler rods.
Stainless Steel Welding Rods/Electrodes
These rods contain chromium and nickel to match stainless steel base metals.
They produce corrosion-resistant welds on stainless alloys.
Examples include E308 or E316 series rods.
They ensure the weld metal composition stays compatible with the parent stainless steel and prevent rust or tarnish.
They may have special coatings to handle the high alloy content.
Cast Iron Welding Rods/Electrodes
Cast iron cannot be welded with ordinary steel rods because it is brittle.
Special iron / nickel-based rods (often called Ni-99, 99% Nickel) are used for cast iron welding.
These nickel rods bond well to cast iron and minimise cracking.
After welding, the joint can be machined.
In TIG welding, there are also nickel TIG fillers for cast iron.
Using the wrong rod on cast iron would lead to porosity and cracking, so matching the rod alloy is crucial.
Aluminium Welding Rods/Electrodes
Welding aluminium requires filler of similar aluminium alloy.
MIG welding uses aluminium MIG welding wire.
TIG uses an aluminium filler rod (ER4043, ER5356, etc.) instead of a steel rod.
Aluminium fillers melt easily but require AC current and cleaning.
These rods handle aluminium’s oxides and high thermal conductivity.
Aluminium rods are not coated (unlike stick rods) but the torch provides argon shielding. .
Copper, Bronze and Others
Copper alloys are welded with bronze or copper-nickel rods.
Bronze rod can join steel to bronze or brass.
Special alloy rods exist for nickel or Monel to weld copper-nickel.
For many metals, matching filler rods exist.
For example, bronze brazing rods are used for brass fittings.
Specialty Alloys
In niche cases, there are electrodes for tool steels, high-temperature alloys, or rare metals.
What Welding Rod Codes Mean
Welding rods (electrodes) are labelled with an AWS code that encodes their key properties.
For example, an electrode marked E7018 follows AWS A5.1 classification.
The code breakdown is as follows:
Prefix Letter (E, R or ER)
Most welding rods begin with ‘E’ (electrode) meaning a current-carrying rod.
‘R’ can indicate a filler rod (used in brazing or gas welding) that is not an electrode.
‘ER’ (electrode, rod) typically means a flux-cored or MIG wire electrode (the filler and electrode are one).
For stick rods, you usually see just ‘E’ at the start.
Tensile Strength (first two or three digits)
After the letter, the first two digits (for four-digit codes like E6010, E7018) or first three digits (for five-digit codes like E10018) give the weld deposit’s minimum tensile strength in kilo-pounds per square inch (ksi).
For example, in E7018 the ‘70’ means 70 ksi (70,000 psi) tensile strength.
Similarly, an E6010 or E6013 has ‘60’ meaning 60 ksi.
Welding Position (third digit)
The next digit tells you which positions the rod can be used in.
A ‘1’ as the third digit means all positions (flat, horizontal, vertical and overhead).
A ‘2’ means flat and horizontal only.
A ‘3’ would mean vertical-down only (rarely used).
A ‘4’ (seen in E7014, E7024 etc.) usually means flat, horizontal, vertical down and overhead.
So in E7018, the ‘1’ indicates it can weld in any position.
Coating Type & Current (final digit)
The last digit (0–8) indicates the electrode coating and which currents/polarities it supports.
Each number stands for a flux type:
- 0 or 1: high-cellulose sodium or potassium (deep penetration, DC+ only or AC/DC for 6010/6011 rods).
- 2 or 3: titania (rutile) coatings for AC/DC.
- 4: iron powder + titania (improves deposition).
- 5,6,8: low-hydrogen coatings (which minimise hydrogen in the weld). For instance, ‘8’ in 7018 means a low-hydrogen iron-powder flux allowing AC or DC.
- 7: potassium-based (less common).
Putting it all together, E7018 means:
- E = Electrode for arc welding,
- 70 = 70,000 psi tensile
- 1 = all positions
- 8 = basic low-hydrogen coating suitable for AC or DC.
By contrast, E6010 means 60 ksi tensile, all-position, high-cellulose sodium flux (fast-freezing, deep penetration).
The Different Colours of Tungsten Electrode Welding Rods
Tungsten electrodes (used in TIG welding) come with different tip colours, each colour denoting a specific alloy and application.
Red Tipped
For example, red-tipped tungsten contains 2% thorium oxide and is called thoriated tungsten.
These red electrodes are durable and give a very stable arc on steel and stainless steel.
White Tipped
White-tipped tungsten has about 0.8% zirconia (zirconium) and is ideal for AC welding of aluminium and magnesium.
It resists contamination and holds up under high current.
Blue Tipped & Grey Tipped
Blue-tipped tungsten contains lanthana (2% lanthanum oxide) and grey-tipped tungsten contains ceria (2% cerium oxide).
Both blue (lanthanated) and grey (ceriated) electrodes start arcs easily and are versatile.
They work well on thin material and with both AC and DC currents.
They give smooth, stable arcs for precision work.
Turquoise Tipped
Turquoise (often labeled Multi Star or rare earth mix) contains a mixture of rare-earth oxides and is suited to many tasks, offering a stable arc and long life.
Purple Tipped
Purple tungsten (E3, containing rare-earths) behaves similarly, giving especially low burn-off and very consistent performance.
Picking the Right Welding Rod
Choosing the correct welding rod is crucial for a strong, defect-free weld, in a similar way to knowing which welding machine is right for you.
The main rule is to match the rod to the base metal and application.
For example, to weld mild steel you would typically use a carbon steel rod.
To weld stainless steel, a stainless filler rod.
To weld cast iron, a nickel-iron rod.
The rod’s alloy and tensile strength should be compatible with the parent metal.
Using the wrong filler can cause cracking, corrosion or a weak joint.
Other Factors
Other factors include welding position and current.
Electrodes are rated for certain positions (flat, horizontal, vertical, overhead).
Some rods only work with DC current (e.g. 6010 rods with DC+), while others (like 6011 or 7018) work with AC or DC.
Always ensure the rod’s specifications match your equipment (AC or DC supply).
Also, consider joint requirements and environment.
Thicker plates may need higher amperage and slower-freezing rods.
Thin sheet may need fast-freezing rods to avoid burn-through.
If you weld outdoors or in windy conditions, a flux-coated rod is better.
Always review your welding procedure and use the AWS code on the electrode or supplier’s guide to confirm compatibility.
Finally, knowing which welding rod to use depending on your type of welding such as TIG vs MIG welding, or stick welding.
Storing Welding Rods
Proper storage of welding rods is vital to maintain their quality.
Electrodes must be kept dry and moisture-free.
Moisture in the air will gradually seep into the flux coating of stick rods, especially low-hydrogen types, which ruins their performance.
A wet rod can give excessive spatter, erratic arcs and hydrogen-induced cracking.
Therefore, store unused rods in a sealed container or cabinet.
Rod Ovens
Many shops use rod ovens or holding ovens to keep electrodes dry.
Low-hydrogen electrodes should be stored at about 110 – 150 °C (225 – 300 °F).
This keeps any moisture out.
In contrast, high-cellulose or fast-freeze rods have more moisture in their coating by design and usually do not need oven storage.
If a rod has been left out in humidity, it must be re-dried (rebaked) before use.
This is typically done by placing it in an oven at the recommended temperature for a specified time.
Manufacturers often specify drying procedures on the rod label.
In any case, always keep rods in a moisture-proof container or oven when not in use.
Keeping rods stored correctly ensures the flux coating works as intended and helps achieve strong, reliable welds.
Final Thoughts
You should now have a better understanding of welding rods.
Welding rods (electrodes) are fundamental tools in metal joining.
They deliver current, create the arc, and often supply the filler metal needed to fuse parts. T
Rods come in various alloys to match the base metal – from carbon steel to stainless, aluminium to cast iron – each with a flux or composition tailored to its material.
Electrodes are labelled with standardized codes that tell you their strength, positions, and coating type.
When welding, always pick a rod whose code and metal type match your job.
The right rod ensures compatibility, strength and weld quality.
By understanding rod types, materials and codes, a welder can choose the proper electrode and produce clean, strong welds safely and effectively.
For more information on welding rods, or help with any and all of your welding needs, get in contact with us here at Xtreme Plasma.