The best stainless steel consumable depends on the grade: 308L is commonly used for 304, 316L for 316, and 309L for joining stainless steel to mild steel. Duplex and super duplex grades require specialist filler metals. Matching the filler metal to the parent grade maintains corrosion resistance and weld strength.
This page covers consumables for the common stainless grades and dissimilar-metal joints. For process formats see MIG wire and TIG rods.
What is the best welding consumable for stainless steel?
The best consumable depends on the stainless steel grade. 308L is commonly used for 304 stainless steel, while 316L is used for 316 stainless steel. 309L is typically selected for joining stainless steel to mild steel. Selecting the correct filler metal helps maintain corrosion resistance and weld strength.
304 stainless steel
What is 304 stainless steel?
304 stainless steel is one of the world’s most widely used stainless steels. It offers excellent corrosion resistance, good weldability and is commonly used in food processing, catering equipment and architectural fabrication. 304 is typically welded using 308L filler metals.
How do you weld 304 stainless steel?
304 stainless steel is commonly welded using TIG or MIG with 308L filler metal. Clean preparation, correct shielding gas and controlled heat input help maintain corrosion resistance and minimise distortion. Avoid contamination from carbon steel tools.
What filler rod should I use for 304 stainless steel?
308L TIG rods and 308LSi MIG wire are the recommended filler metals for welding 304 and 304L stainless steel. These consumables provide excellent corrosion resistance and weld quality.
316 stainless steel
What is 316 stainless steel?
316 stainless steel contains molybdenum, giving it improved corrosion resistance compared with 304. It is widely used in marine, pharmaceutical and chemical processing industries. 316 is typically welded using 316L filler metals.
How do you weld 316 stainless steel?
Use 316L filler rods or 316LSi MIG wire with appropriate Argon-based shielding gas. Maintain clean joint preparation and controlled heat input to preserve corrosion resistance. Back purging may be required for pipework and hygienic applications.
What filler metal should I use for 316 stainless steel?
316L filler rods or 316LSi MIG wire are recommended for welding 316 stainless steel. Using matching filler metals helps maintain corrosion resistance in demanding environments.
Duplex stainless steel
What is duplex stainless steel?
Duplex stainless steel combines austenitic and ferritic microstructures to provide excellent strength and corrosion resistance. It is widely used in offshore, marine and chemical processing industries.
How do you weld duplex stainless steel?
Duplex stainless steel requires specialist filler metals, controlled heat input and suitable shielding gases to maintain the correct ferrite balance. Approved welding procedures should always be followed.
What filler metal should I use for duplex stainless steel?
Use duplex filler metals specifically designed for the parent material being welded. Standard stainless steel filler rods are generally not suitable for duplex applications.
Super duplex stainless steel
What is super duplex stainless steel?
Super Duplex stainless steel offers even greater strength and corrosion resistance than standard duplex grades. It is commonly used in offshore oil and gas, desalination and aggressive chemical environments.
How do you weld super duplex stainless steel?
Super Duplex welding requires strict heat input control, specialist filler metals and correct shielding gas. Maintaining the correct weld metallurgy is essential for long-term performance.
Welding stainless steel to mild steel
Can I weld stainless steel to mild steel?
Yes. Stainless steel can be welded to mild steel using 309L filler rods or 309LSi MIG wire. These filler metals are specifically designed for dissimilar metal welding and help produce strong, reliable joints.
How do you weld dissimilar metals?
Dissimilar metals can often be welded using specialist filler metals such as 309L stainless steel filler rods. The correct consumable depends on the materials being joined and the intended service conditions. Technical guidance is recommended for challenging material combinations.
What filler metal should I use for dissimilar metal welding?
309L is one of the most commonly used filler metals for welding stainless steel to mild steel. Other dissimilar metal applications may require specialist nickel-based consumables. Always select the filler metal according to the parent materials and the welding procedure.
Quick stainless consumable reference
- 304 / 304L — 308L (TIG) / 308LSi (MIG)
- 316 — 316L (TIG) / 316LSi (MIG)
- Stainless to mild steel — 309L / 309LSi
- Duplex — specialist duplex filler metals
- Super duplex — specialist super duplex filler metals
Choosing stainless consumables with Weldability SIF
Matching the filler to the grade — and keeping stainless work free of carbon-steel contamination — is what preserves corrosion resistance in service. Weldability SIF supplies 308L, 316L, 309L and specialist duplex consumables across the UK, with technical advice to help you select correctly. Contact us for support.