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TIG Rods and Cut-Length Filler

TIG filler is sold as straight cut-length rods in tubes or boxes, with each rod carrying its classification. This sheet covers the common carbon, stainless and aluminum rods, how cut-length filler is packaged and marked, and how to match a rod to a job.

Ref WG-0107AWS A5.18AWS A5.9AWS A5.10

Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.

What it is

Gas tungsten arc welding (GTAW or TIG) uses a non-consumable tungsten electrode, and filler is added by hand from a straight rod. Cut-length rods are classified in the same AWS specifications as the matching wire: AWS A5.18 for carbon steel, AWS A5.9 for stainless steel and AWS A5.10 for aluminum. Rods are the same chemistry as MIG wire of the same class but are cut to length and packed in tubes or cartons. The common length in North America is 36 in. Imported rods are often 1 m.

How to identify

AWS specifications require cut-length filler to be identified with its classification. Makers stamp or emboss the class near one end of each rod or use a flag tag. If rods have been mixed in a tray, read the stamp. Do not guess from color. Carbon steel rods are often copper coated. Stainless rods are bright. Aluminum rods are dull silver and much lighter. Diameter is on the tube label and can be checked with calipers. See measuring wire and electrode diameter.

Common TIG rods

Class	Spec	Base metal	Notes
ER70S-2	AWS A5.18	Carbon steel	Extra deoxidizers; good on slightly dirty steel and root passes
ER70S-6	AWS A5.18	Carbon steel	Higher silicon and manganese; common general rod
ER308L	AWS A5.9	304 and 304L stainless	Low carbon
ER309L	AWS A5.9	Stainless to carbon steel	Dissimilar joints
ER316L	AWS A5.9	316 and 316L stainless	Contains molybdenum
ER4043	AWS A5.10	6xxx and cast aluminum	Fluid, crack resistant
ER5356	AWS A5.10	5xxx and 6xxx aluminum	Higher strength, better anodize match

Packaging

Package	Typical content	Notes
Tube	Small weight of one class and diameter	Keeps rods clean; label shows class, size and lot
Carton	Larger weight, often several tubes	Common for shops buying in volume
Sample or mixed pack	A few rods of several classes	Useful for maintenance trucks

Key points

Match rod diameter to material thickness and amperage. Thin work uses small rod.
Keep rods in their tube. Oil, moisture and shop dust cause porosity.
Aluminum rod oxidizes over time. Store it dry and wipe it with a clean cloth and approved solvent before use.
Keep the lot number when a job requires filler traceability.
See the stainless filler selection chart and the aluminum filler metals sheet for base metal matches.

Common mistakes

Using MIG wire cut from a spool as rod on code work that needs certified cut lengths.
Mixing unmarked rods in a tray.
Leaving aluminum rod uncovered in a damp shop.
Picking ER70S-6 for stainless because "steel is steel."

Governing standards: AWS A5.18 (carbon steel filler for gas shielded arc welding); AWS A5.9 (stainless steel filler); AWS A5.10 (aluminum filler). Filler maker data sheets.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.

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