Lincoln Electric Innershield® NR-555 is a self-shielded, all-position flux-cored arc welding (FCAW-S) wire classified per AWS A5.29: E81T8-Ni2-H8 for high-strength structural applications requiring both notch toughness and controlled diffusible hydrogen without external shielding gas. As an E81T8 electrode, NR-555 deposits weld metal meeting an 80 ksi (550 MPa) minimum tensile strength requirement — placing it in the higher-strength tier above the common E71T-8 class — while its Ni₂ designation provides approximately 2 % nickel for low-temperature Charpy V-Notch impact toughness. The H8 designation confirms diffusible hydrogen at ≤ 8 mL/100 g. NR-555 meets AWS D1.8 seismic supplement requirements and is the specification-grade self-shielded consumable for seismic moment connections, heavy structural fabrication, and offshore applications where gas shielding is not available or practical.
| Parameter | Value |
|---|---|
| AWS Classification | E81T8-Ni2-H8 (AWS A5.29 / ASME SFA-A5.29) |
| Applicable Standard | AWS A5.29 (Low Alloy Steel Electrodes for FCAW) |
| This SKU | 5/64 in (2.0 mm), 25 lb plastic spool (ED035566) |
| Shielding Gas | None — self-shielded (FCAW-S) |
| Polarity | DCEN (DC electrode negative) |
| Welding Positions | All positions (1G, 2G, 3G, 4G) |
| Tensile Strength (required E81T8) | 550–690 MPa (80–100 ksi) |
| Yield Strength (typical) | ~480–500 MPa (70–72 ksi) as-welded |
| Elongation | 19 % minimum per AWS A5.29 |
| Charpy V-Notch Impact | 27 J (20 ft-lbf) minimum at −29 °C (−20 °F) |
| Diffusible Hydrogen | ≤ 8.0 mL/100 g (H8 designation) |
| Nickel Content | ~2 % Ni in weld deposit |
| Seismic Compliance | AWS D1.8 seismic supplement lot-waiver requirements |
NR-555's combination of 80 ksi tensile strength, Ni₂ impact toughness, H8 hydrogen control, and D1.8 seismic compliance makes it one of the most capable self-shielded FCAW consumables available for code-governed structural work:
- Seismic moment frame fabrication — full-penetration and fillet welds on demand-critical connections per AISC 341 and AWS D1.8, including special moment frames (SMF) and intermediate moment frames (IMF)
- High-strength structural fabrication — A572 Grade 50 and A992 steel connections, heavy W-shapes, and built-up plate girders requiring 80 ksi consumable tensile strength overmatch
- Offshore and marine construction — platform jacket nodes, riser clamps, and subsea structural nodes where low-temperature CVN toughness at −20 °F is specified
- Bridge fabrication — primary member welds on fracture-critical members where both high strength and toughness with controlled hydrogen are required
- Field repair and maintenance — high-strength component repairs in outdoor environments where gas shielding cannot be maintained
NR-555 is classified under AWS A5.29 (Low Alloy Steel Electrodes for Flux Cored Arc Welding) rather than the more common AWS A5.20, reflecting its enhanced alloy system including approximately 2 % nickel for CVN toughness at −20 °F. The H8 hydrogen designation — achieved through careful flux formulation and packaging — is one full step lower than the H16 level of NR-233, making NR-555 the appropriate choice when crack-sensitive base metals, high restraint, or code requirements demand the lowest achievable hydrogen from a self-shielded process.
NR-555 operates on DCEN at extended stick-out per the Innershield process standard. At 5/64 in diameter, typical operating parameters are 110 in/min wire feed speed at 19 V, with electrode stick-out of approximately 7/8 in (22 mm). The welder-friendly arc and flat bead face in out-of-position fillets and groove welds allow operators at all skill levels to achieve consistent results. Per Lincoln Electric specifications, NR-555 meets AWS D1.8 seismic supplement lot-waiver requirements.
| Diameter | Polarity | ESO | WFS (in/min) | Voltage (V) | Position |
|---|---|---|---|---|---|
| 5/64 in (2.0 mm) | DCEN | 7/8 in (22 mm) | 90–130 | 18–21 | All positions |
| 5/64 in (2.0 mm) | DCEN | 7/8 in (22 mm) | 110 (recommended) | 19 | All positions |
Innershield NR-555 is classified as E81T8-Ni2-H8 per AWS A5.29 (Low Alloy Steel Electrodes for Flux Cored Arc Welding). The "81" indicates a minimum 80 ksi tensile strength; "T8" is an all-position, self-shielded, DCEN electrode with specified CVN impact toughness; "Ni2" identifies approximately 2 % nickel weld deposit chemistry; and "H8" confirms diffusible hydrogen ≤ 8 mL/100 g.
NR-233 is classified E71T-8-H16 (70 ksi tensile minimum, H16 hydrogen) while NR-555 is classified E81T8-Ni2-H8 (80 ksi tensile minimum, ~2 % Ni, H8 hydrogen). NR-555 is the higher-strength, lower-hydrogen option — chosen when base metal tensile strength requires overmatch at 80 ksi, when low-temperature CVN toughness needs nickel enhancement, or when the most stringent hydrogen control is needed from a self-shielded process.
Yes. Innershield NR-555 meets AWS D1.8 Structural Welding Code — Seismic Supplement lot-waiver requirements. Its E81T8 CVN impact toughness (27 J minimum at −29 °C), H8 diffusible hydrogen control, and 80 ksi tensile strength satisfy the toughness, strength, and hydrogen requirements for demand-critical welds in seismic moment frames where self-shielded FCAW is specified.
NR-555 uses DCEN (DC Electrode Negative). Connect the gun/torch lead to the negative output terminal and the work clamp to the positive terminal. Verify polarity on the power source before welding — incorrect polarity will produce unstable arc characteristics and non-compliant weld properties.
The ~2 % nickel in NR-555's weld deposit (Ni2 classification per AWS A5.29) enhances low-temperature Charpy V-Notch impact toughness. Nickel lowers the ductile-to-brittle transition temperature of the ferrite microstructure, enabling the weld metal to absorb impact energy at −29 °C (−20 °F) without brittle fracture. This is essential for seismic moment frame connections, bridge fracture-critical members, and cold-climate offshore applications where toughness at sub-zero temperatures is mandated by code or specification.
Browse the full welding wire collection, or compare to Innershield NR-233 (E71T-8-H16) for the 70 ksi all-position self-shielded option, or Outershield 71 Elite for the gas-shielded equivalent.