Lincoln Excalibur 308L is a low-carbon E308L-16 stainless steel welding rod engineered to weld Type 304 and 304L austenitic stainless steel — the most widely used stainless steel grades in food processing, pharmaceutical manufacturing, architectural, and general industrial applications. With weld metal carbon content ≤ 0.04 % and a balanced 19–21 Cr / 9–11 Ni chemistry, Excalibur 308L prevents sensitization-induced intergranular corrosion while delivering smooth AC and DCEP arc performance in all positions.
Excalibur 308L is Lincoln Electric's premium E308L-16 SMAW electrode for Type 304 and 304L stainless steel. The AWS designation E308L-16 decodes as: "E" = electrode; "308L" = 18-8 chromium-nickel chemistry with low carbon (≤ 0.04 %); "-16" = rutile-basic flux enabling AC and DCEP welding in all positions. Like all Excalibur stainless rods, the 308L version uses tightly controlled flux chemistry to ensure consistent ferrite content (FN 3–10 typical), which prevents hot cracking in the austenitic weld metal during rapid solidification. The "L" (low carbon) classification means post-weld sensitization — the precipitation of chromium carbides that depletes HAZ chromium and creates corrosion pathways — does not occur even in thick multi-pass welds. This makes Excalibur 308L ideal for service involving aqueous, acidic, or food-contact media without post-weld solution annealing. Excalibur 308L is to 304/304L stainless welding what Excalibur 7018 MR is to carbon-steel welding — a reliable, production-proven Lincoln flagship electrode.
| Property | Specification |
|---|---|
| AWS Classification | E308L-16 |
| AWS Standard | AWS A5.4/A5.4M |
| Carbon (max) | 0.04% |
| Chromium | 19.0–21.0% |
| Nickel | 9.0–11.0% |
| Tensile Strength (min.) | 74,000 psi (510 MPa) |
| Yield Strength (min.) | 54,000 psi (372 MPa) |
| Elongation (min.) | 35% |
| Flux Type | Rutile-basic (-16) |
| Current | AC, DCEP |
| Positions | All |
| Diameters | 3/32, 1/8, 5/32, 3/16 in |
The 35 % elongation minimum is among the highest for any AWS A5.4 electrode classification, confirming excellent ductility and impact toughness in the 308L weld metal — important for equipment subject to thermal cycling, vibration, or cryogenic service down to -320 °F.
- Type 304 and 304L stainless steel piping, vessels, tanks, and sheet metal — the primary base metal application for E308L-16 weld metal.
- Food processing and dairy equipment — sanitary stainless construction per 3-A dairy standards and FDA requirements for food-contact surfaces.
- Pharmaceutical vessels and bioreactors — USP water systems, CIP (clean-in-place) circuits, and sanitary fittings where passivation must be maintained.
- Architectural and cladding stainless — handrails, facades, and trim work where appearance weld quality matters.
- Repair welding of 304 stainless components — heat exchangers, process piping, storage tanks, and equipment in chemical and petrochemical plants.
- Dissimilar welds: 304 to 308, 304 to 304L, or 304 to 321 — E308L-16 is conservative and compatible with standard and L-grade 304 family base metals.
- Cryogenic service — E308L weld metal remains ductile down to liquid nitrogen temperatures (-320 °F), making it suitable for cryogenic vessels and LNG/LOX storage systems.
| Diameter | Amperage Range | Typical Use |
|---|---|---|
| 3/32 in (2.4 mm) | 50–75 A | Thin-wall pipe, sheet metal, root passes |
| 1/8 in (3.2 mm) | 70–110 A | Standard piping, vessel walls, fittings |
| 5/32 in (4.0 mm) | 95–140 A | Medium-section vessels, structural |
| 3/16 in (4.8 mm) | 120–170 A | Heavy fill passes on thick plate |
Key technique points for 308L stainless SMAW:
- Interpass temperature: Always keep below 300 °F (150 °C) between passes. Stainless holds heat poorly — more time between passes is required than with carbon steel of equivalent thickness.
- Arc length: Keep tight — approximately 1× core diameter. Long arc length on stainless increases nitrogen and oxygen pickup from the atmosphere, promoting porosity and loss of corrosion resistance.
- Stainless-dedicated wire brush: Use only SS wire brushes between passes. Carbon-steel bristle contamination embeds iron particles that corrode and compromise the passive oxide layer of completed welds.
- Distortion control: Use tack welding sequences, back-step technique, and fixturing to minimize distortion on thin 304 sheet and plate. Stainless has 50 % higher thermal expansion than carbon steel and significant distortion without control.
- Sealed container: Store in original sealed Lincoln container in a dry area (below 70 % RH, 40–100 °F). Indefinite shelf life in sealed packaging.
- Re-drying: If moisture-exposed, dry at 300–350 °F for 1–2 hours before use. Do not exceed 400 °F.
- Holding oven: In high-humidity production shops, keep opened canisters in a 200–250 °F holding oven between uses.
- Contamination prevention: Store stainless electrodes away from carbon-steel electrodes, grinding dust, and carbon-steel chips. Even residual iron contamination on the flux surface can cause arc instability and iron porosity in stainless welds.
Primary compatible base metals:
- Type 304, 304L austenitic stainless (UNS S30400, S30403)
- Type 302, 302B, 303 (for non-critical or general repair use)
- Type 308, 308L
- Dissimilar: 304/304L to 321 (note: for high-temperature 321 service involving creep, verify with metallurgical specialist)
Joint types: all groove and fillet types in all positions. Follow ASME Section IX for pressure-containing joints. PWHT is not required and should be avoided for austenitic stainless — annealing in the sensitizing range defeats the purpose of the L-grade chemistry.
Q: What is the difference between E308-16 and E308L-16?
E308L-16 limits carbon to ≤ 0.04 % vs. ≤ 0.08 % for E308-16. Low carbon prevents sensitization — the precipitation of chromium carbides at grain boundaries — which can lead to intergranular corrosion in welded joints exposed to aqueous media. For any food, pharmaceutical, or corrosion-critical application, specify E308L-16.
Q: Can I use 308L to weld 304H stainless?
304H contains higher carbon (0.04–0.10 %) for elevated-temperature creep strength. E308L-16 does not match the elevated-temperature strength of 304H weld metal. For high-temperature service (above 1100 °F), use E308H-16. For ambient-temperature service or repair, E308L-16 is acceptable — confirm with the applicable code.
Q: Why is the ferrite number important in 308L weld metal?
A small amount of delta ferrite (FN 3–10) in the fully austenitic weld metal acts as a hot cracking inhibitor. Pure austenite has a continuous grain structure through which solidification cracks can propagate. Ferrite creates discontinuities that arrest crack propagation. Too much ferrite (FN > 15) reduces impact toughness and corrosion resistance. Lincoln controls Excalibur 308L flux to consistently deliver FN 4–8.
Q: Is E308L-16 suitable for cryogenic LNG service?
Yes. Austenitic stainless steel weld metal (E308L type) maintains excellent impact toughness down to -320 °F and is widely used for LNG, LOX, and liquid nitrogen service. Verify with the applicable design code (ASME Section VIII, BS EN 13458, etc.) for specific impact testing requirements at service temperature.
Q: What cleaning process should I use before welding 304 stainless?
(1) Degrease with acetone or isopropyl alcohol to remove all oils, greases, and cutting fluids; (2) Remove any mill scale, heavy oxides, or laser-cut dross with a stainless wire brush or abrasive flap disc; (3) Do not use carbon-steel tools that can embed iron particles; (4) Keep the joint clean and dry before welding. Do not touch cleaned surfaces with bare hands — skin oils cause porosity and affect the passive oxide layer.
Q: What is the best electrode size for thin-wall 304 tubing (Schedule 10, 2 in OD)?
For 2 in Schedule 10 pipe (0.109 in wall), use 3/32 in E308L-16 at 55–70 A DCEP. The thin wall requires careful amperage control and short arc length to prevent burn-through. Back-purge with argon for root passes on pipe that will contact product.
Q: Can I use E308L-16 on 316 stainless?
E308L-16 lacks the molybdenum addition (2–3 %) present in 316 weld metal. In most general fabrication and repair situations, E308L-16 is used as a budget substitute for 316/316L filler — the weld will have somewhat less pitting and crevice corrosion resistance in chloride environments. For service in chloride or acidic media, use E316L-16 to maintain full corrosion performance.
Type 304 and 304L austenitic stainless steel is the most widely used stainless grade in food service, pharmaceutical, architectural, and general industrial applications — accounting for approximately 50% of all stainless steel consumed globally. For any welding performed on 304/304L, the E308L-16 electrode (Excalibur 308L) is the standard filler metal recommendation. The 18% chromium and 10% nickel in the weld metal deposit match the 304 alloy system, providing equivalent corrosion resistance and austenitic structure in the weld metal and HAZ. The L-grade carbon limitation (0.04% max) prevents sensitization — a critical concern for food processing, pharmaceutical, and water treatment applications where intergranular corrosion at weld HAZs would compromise product purity or pipe integrity. Passive film restoration (passivation) after welding — typically with nitric acid or citric acid solution per ASTM A380 or ASTM A967 — restores the full corrosion resistance of the weld and adjacent HAZ surface. For all food, pharmaceutical, and potable water applications, specify post-weld passivation in the fabrication procedure. Excalibur 308L provides the substrate quality (proper ferrite control, low carbon, clean slag) that supports effective passivation without corrosion-compromising defects in the weld surface.