Materials
What filler wire or rod for stainless steel?
Quick answer
For stainless steel use ER308L (304 grade), ER316L (316 grade) — match the parent metal. Matching filler to the parent grade is the rule — mismatched filler either cracks, corrodes or underperforms the base metal.
Filler selection
- Process choice: TIG for quality, MIG with tri-mix or 98/2 argon-CO2 for speed
- Filler: ER308L (304 grade), ER316L (316 grade) — match the parent metal
- Prep: dedicated stainless brushes and discs — carbon steel contamination causes rust later
Why matching matters
Filler chemistry controls strength, corrosion behaviour and crack resistance. The classic Australian mistake is welding 316 stainless with 308 filler — it works, until the job sits in a coastal or chemical environment and the weld rusts first. When in doubt, weld with a filler at least as alloyed as the parent.