For most mild and structural steel, ER70S-6 MIG wire, ER70S-2 TIG rods and 6013 or 7018 MMA electrodes are widely used. High-strength and wear-resistant grades such as Hardox, Domex and weathering steel need low-hydrogen or matching consumables. The correct choice depends on the grade, welding process, material thickness and required mechanical properties.
This page covers consumables for mild steel, the common structural grades (S275, S355), and specialist steels. For process-specific detail see MIG wire, TIG rods and MMA electrodes.
What is the best welding consumable for mild steel?
For most mild steel applications, ER70S-6 MIG wire, ER70S-2 TIG rods and 6013 or 7018 MMA electrodes are widely used. The correct choice depends on the welding process, material thickness and required mechanical properties.
Which consumables are best for structural steel?
Structural steel applications commonly use ER70S-6 MIG wire, 7018 low-hydrogen electrodes and gas-shielded flux-cored wires. These consumables provide excellent mechanical properties and are suitable for heavy fabrication and construction.
S275 structural steel
What is S275 steel?
S275 is a structural mild steel widely used in construction, fabrication and engineering. It offers good weldability, strength and machinability, making it suitable for beams, columns, platforms and general fabricated structures. S275 can be welded using MIG, TIG or MMA processes with consumables such as ER70S-6 MIG wire, ER70S-2 TIG rods or 7018 electrodes.
How do you weld S275 steel?
S275 steel is easily welded using MIG, TIG or MMA welding. Ensure the material is clean, use the correct filler metal and select appropriate welding parameters for the material thickness. For most fabrication work, ER70S-6 MIG wire or 7018 low-hydrogen electrodes provide excellent results.
What filler metal should I use for S275 steel?
ER70S-6 MIG wire, ER70S-2 TIG rods and 7018 MMA electrodes are commonly used for S275 structural steel. These consumables provide excellent strength and are widely used in fabrication and structural engineering. The best choice depends on the welding process, joint design and any mechanical property requirements.
S355 structural steel
What is S355 steel?
S355 is a high-strength structural steel commonly used in construction, bridges, cranes and heavy engineering. It offers greater strength than S275 while maintaining good weldability. Correct filler metal selection is important to maintain structural performance.
How do you weld S355 steel?
S355 can be welded successfully using MIG, TIG, MMA and flux-cored processes. Use low-hydrogen consumables where required and follow approved welding procedures for thicker sections. Preheating may be necessary depending on material thickness and carbon equivalent.
What filler metal should I use for S355 steel?
ER70S-6 MIG wire is commonly used for general fabrication, while 7018 low-hydrogen electrodes are widely used for structural and coded welding. Always ensure the filler metal meets the required mechanical properties and the toughness requirements of the welding procedure.
Hardox wear plate
What is Hardox steel?
Hardox is a wear-resistant steel plate designed for high abrasion environments such as mining, quarrying and earthmoving equipment. Although weldable, correct filler metal selection is important to avoid cracking.
How do you weld Hardox steel?
Hardox should be welded using low-hydrogen consumables and appropriate preheat where required. Always follow the manufacturer’s welding recommendations for the specific Hardox grade.
What filler metal should I use for Hardox?
Hardox wear plate is typically welded using low-hydrogen consumables or filler metals recommended by the plate manufacturer. Low-hydrogen electrodes and suitable MIG or flux-cored wires are commonly used depending on the application — the correct filler metal depends on whether wear resistance or structural strength is the priority. Following the correct welding procedure helps maintain strength and wear resistance.
Domex high-strength steel
What is Domex steel?
Domex is a high-strength structural steel designed for lightweight construction and high-performance fabrication. It offers excellent weldability while providing increased yield strength.
How do you weld Domex steel?
Domex steels are generally welded using low-hydrogen consumables with controlled heat input. Correct filler selection helps maintain strength and minimise distortion.
Weathering steel
What is weathering steel?
Weathering steel, often known by trade names such as COR-TEN®, develops a protective oxide layer that improves atmospheric corrosion resistance. It is widely used in bridges, architectural structures and outdoor installations.
How do you weld weathering steel?
Weathering steel should be welded using filler metals specifically designed to match its corrosion-resistant properties. Selecting the correct consumables helps maintain appearance and long-term durability.
What filler metal should I use for weathering steel?
Weathering steel requires matching filler metals formulated for atmospheric corrosion resistance. Using standard mild steel filler metals may affect the appearance and weathering characteristics of the finished structure.
Can galvanised steel be welded?
Yes. Galvanised steel can be welded, but the zinc coating should be removed from the weld area where possible to improve weld quality and reduce zinc fumes. Appropriate ventilation or fume extraction should always be used when welding galvanised materials.
Quick steel consumable reference
- Mild steel — ER70S-6 (MIG), ER70S-2 (TIG), 6013 or 7018 (MMA)
- S275 / S355 structural — ER70S-6, ER70S-2, 7018 low-hydrogen
- Hardox — low-hydrogen electrodes / MIG / flux-cored per manufacturer
- Domex — low-hydrogen consumables, controlled heat input
- Weathering steel — matching corrosion-resistant filler metals
Choosing steel consumables with Weldability SIF
From everyday mild steel to coded structural and wear-resistant grades, getting the filler metal right protects strength, toughness and durability. Weldability SIF supplies consumables for the full range of steels across the UK, with technical advice to match the correct product to your grade and procedure. Contact us for support.