Electrode comparison
E308L vs ER308L
Same 19Cr-10Ni low-carbon chemistry. E308L is a flux-covered stick electrode; ER308L is bare wire or rod for MIG and TIG.
E308L vs ER308L at a glance
| E308L | ER308L | |
|---|---|---|
| AWS specification | AWS A5.4/A5.4M | AWS A5.9/A5.9M |
| Process | Stick (SMAW) | TIG (GTAW) / MIG (GMAW) |
| Form | Covered electrode | Solid wire / rod |
| Tensile strength (min) | 75 ksi | 75 ksi |
| Yield strength (min) | 45 ksi | 45 ksi |
| Elongation (min) | 35% | 35% |
| Impact toughness | Not required; austenitic deposits stay tough to cryogenic temperatures | Not required; austenitic deposits stay tough to cryogenic temperatures |
| Polarity | DCEP, AC | DCEP (GMAW), DCEN (GTAW) |
| Positions | Flat, Horizontal, Vertical, Overhead | Flat, Horizontal, Vertical, Overhead |
| Penetration | Shallow to medium | Medium |
| Deposition rate | Medium | Medium to high depending on process |
| Coating / core | Lime-titania (-16) | None — bare wire or rod |
| Slag | Self-lifting, brittle, must be removed completely between passes | None; a light oxide film should be brushed or pickled off |
| Shielding gas | None — self-shielding | 100% argon for TIG; tri-mix 90% He / 7.5% Ar / 2.5% CO2 for spray MIG |
| Storage | Keep dry. Stainless coatings pick up moisture and cause porosity and worm tracks. | Keep clean and dry. Contamination, not moisture, is the main enemy for bare stainless filler. |
| Primary use | Food, dairy and beverage equipment | Sanitary tube and pipe welding for food, dairy and pharma |
Which should you use?
The alloy is effectively the same — both are low-carbon 19Cr-10Ni fillers for Type 304 and 304L, with ER308L held to a slightly tighter 0.03% carbon maximum against E308L's 0.04%. The difference is entirely process. E308L is a covered electrode: portable, works in wind, leaves slag that must be chipped between every pass. ER308L is bare: no slag, cleaner welds, far better control, and the only sensible choice for sanitary tube, thin material and anything where the weld will be inspected or polished.
Choose E308L when
- Field repair on stainless with no gas available
- Thick sections and heavy fabrication
- Windy conditions
Choose ER308L when
- Sanitary tube, food and pharmaceutical piping
- Thin sheet and tube
- Welds that will be polished, inspected or left visible
- Root passes where a back purge is used
Amperage compared
| Diameter | E308L | ER308L |
|---|---|---|
| 3/32 in (2.4 mm) | 40–80 A | — |
| 1/8 in (3.2 mm) | 65–110 A | — |
| 5/32 in (4.0 mm) | 95–150 A | — |
| 3/16 in (4.8 mm) | 130–190 A | — |
| 0.030 in (0.8 mm) MIG | — | 50–150 A |
| 0.035 in (0.9 mm) MIG | — | 70–180 A |
| 0.045 in (1.2 mm) MIG | — | 100–250 A |
| 1/16 in (1.6 mm) TIG | — | 40–90 A |
| 3/32 in (2.4 mm) TIG | — | 70–130 A |
| 1/8 in (3.2 mm) TIG | — | 100–180 A |
Ranges are typical starting points. Diameters listed for only one electrode are shown as — for the other.
E308L vs ER308L — common questions
Is the weld metal the same?
Essentially, though ER308L is held to a slightly lower carbon maximum. In service both give the same corrosion resistance on 304 base metal.
Which produces a cleaner weld?
ER308L. With no flux there is no slag to trap between passes and no slag residue to remove, which matters a great deal on sanitary and inspected work.
Do both need a back purge?
On pipe roots, yes. Sugaring is caused by oxygen reaching the hot unshielded root, and that happens regardless of which process laid the pass.
Full specifications
E308L
AWS A5.4/A5.4M
E308L is the standard stick electrode for welding 304 and 304L stainless, with a low 0.04% maximum carbon that protects against intergranular corrosion.
ER308L
AWS A5.9/A5.9M
ER308L is the bare wire and TIG rod for 304 and 304L stainless — the same low-carbon 19Cr-10Ni chemistry as E308L, without a flux coating.