Filler metal and shielding gas selector
Select the two base metals and the welding process. BenchMaths suggests the usual filler metal with AWS and EN ISO designations, the shielding gas and, where needed, the backing gas, with the reasons that matter for that pair of materials.
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What it calculates
- Filler wire or electrode: AWS A5.18/A5.28/A5.9 and EN ISO 14341, 14343 designations
- Shielding gas (e.g. M21 Ar/CO2, Ar/O2, pure Ar) and backing gas
- Dissimilar joints: carbon steel to stainless (309L), high-strength steels, Cr-Mo creep-resistant steels, aluminium alloys
- Notes on undermatching, hydrogen and dilution for the selected pair
Worked example
S355J2 welded to 1.4404 (316L) with MAG: a 309L (EN ISO 14343 23 12 L) wire with Ar + 2–3 % CO2 is the usual choice, because it tolerates dilution from the carbon steel side without martensite.
How to use it
- Create a free account with Google or e-mail.
- Open the calculator and enter your values; units can be metric or imperial.
- Read the result with its formula and source, and export to PDF, DXF or CSV where available.
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Frequently asked questions
Which wire do I use to weld carbon steel to stainless steel?
Usually a 309L type (EN ISO 14343 23 12 L, AWS ER309L). Its higher alloy content absorbs dilution from the carbon steel and keeps some ferrite in the weld metal.
Why use an undermatching filler on Hardox?
Wear plates are usually welded with a lower-strength, tougher filler to reduce the risk of hydrogen cracking; the calculator explains when matching filler is needed instead.
Does it cover TIG and stick welding?
Yes. You can choose MIG/MAG solid wire, flux-cored wire, TIG and manual metal arc.
Guides
- How to weld Hardox wear plateHardox is a quenched and tempered wear-resistant steel.
- When to use 309L filler metal309L is the standard filler metal for joining carbon or low-alloy steel to austenitic stainless steel such as 304L or 316L.
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Results are engineering estimates for planning. They do not replace the applicable standard, a qualified procedure or a check by a qualified engineer.