AWS A5.4/A5.4M · Stainless Steel
E347 Welding Electrode
E347 is niobium-stabilized stainless — the niobium ties up carbon so the weld resists intergranular attack even after long exposure at elevated temperature.
- 75 ksi tensile
- Polarity DCEP, AC
- 4 positions
- Shallow to medium penetration
- Stick (SMAW)
What E347 means
| Part | Meaning |
|---|---|
| E | Covered electrode for shielded metal arc welding |
| 347 | 19Cr-10Ni stabilized with niobium (columbium), typically 8x the carbon content minimum |
| -16 | Lime-titania coating usable on AC or DCEP |
E347 specifications
| AWS specification | AWS A5.4/A5.4M |
|---|---|
| Process | Stick (SMAW) |
| Form | Covered electrode |
| Polarity | DCEP, AC |
| Welding positions | Flat, Horizontal, Vertical, Overhead |
| Tensile strength (min) | 75 ksi (520 MPa) |
| Yield strength (min) | 45 ksi (310 MPa) |
| Elongation (min) | 30% |
| Impact toughness | Not required by the specification |
| Coating / core | Lime-titania (-16) |
| Penetration | Shallow to medium |
| Deposition rate | Medium |
| Slag | Self-lifting, remove fully between passes |
| Arc character | Smooth, slightly stiffer than E308L |
| Shielding gas | None — self-shielding |
E347 amperage by diameter
Typical operating ranges. Start near the middle of the range, then adjust by sound and bead profile. Reduce 10–15% for vertical and overhead work.
| Diameter | Amperage range | Typical start |
|---|---|---|
| 3/32 in (2.4 mm) | 40–80 A | 60 A |
| 1/8 in (3.2 mm) | 65–110 A | 88 A |
| 5/32 in (4.0 mm) | 95–150 A | 122 A |
| 3/16 in (4.8 mm) | 130–190 A | 160 A |
Polarity: DCEP standard; -16 coating also runs on AC.
What E347 is used for
- High-temperature piping and exhaust systems
- Refinery and petrochemical process equipment
- Aircraft and turbine exhaust components
- Joints that will be stress relieved or see long service between 800 and 1500 °F
- Welding Type 321 base metal, which cannot be matched with a titanium-stabilized electrode
Base metals
- Type 347 and 321
- Type 304 in elevated-temperature service
- Stabilized austenitic grades
Characteristics
- Niobium (columbium) preferentially forms carbides, leaving chromium in solution to resist corrosion
- Stabilization works over long exposures where even a low-carbon L grade would eventually sensitize
- Type 321 is titanium-stabilized, but titanium does not transfer across the arc — so 321 base metal is welded with 347 filler
- Somewhat more prone to hot cracking than E308L if ferrite runs low; keep heat input modest
- Retains strength at elevated temperature better than the plain 308 chemistry
Storage and handling
Dry storage; rod oven at 250–300 °F (120–150 °C) after opening.
- Same moisture discipline as other stainless covered electrodes.
- Redry damp rods per the manufacturer's data sheet, typically 500–600 °F (260–315 °C) for one hour.
- Keep isolated from carbon steel consumables.
Welding tips
- Use stringer beads and keep heat input low; weaving raises the hot-cracking risk on stabilized chemistries.
- Interpass temperature below 350 °F (175 °C).
- For Type 321 base metal, E347 is the correct choice — there is no commercially useful 321 covered electrode.
- If the service is below about 800 °F and short-term, E308L is usually cheaper and sufficient.
E347 frequently asked questions
What is the difference between E347 and E308L?
E347 is stabilized with niobium, which locks up carbon permanently. E308L simply keeps carbon low. For long service in the 800–1500 °F sensitization range, stabilization holds up better; for ordinary ambient-temperature corrosion service, E308L is adequate and cheaper.
Why is 321 stainless welded with 347 filler?
Type 321 is stabilized with titanium, but titanium oxidizes and does not survive transfer across the welding arc. Niobium does, so 347 filler delivers the same stabilizing effect in the weld metal.
What amperage for 1/8 in E347?
65–110 A DCEP, typically around 80–95 A.
Is E347 more crack sensitive?
Slightly. Stabilized chemistries are a little more prone to hot cracking than plain 308. Keep heat input modest, use stringer beads, and do not let interpass temperature climb.
Can E347 be used on 304 stainless?
Yes, and it is a good choice when 304 will see extended elevated-temperature service. For ordinary room-temperature corrosion resistance, E308L is the standard filler.
Compare E347 with
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