Lincoln 503609-2 Conarc 48

Product Overview

What Is Lincoln Conarc 48 Welding Electrode?

Lincoln Electric 503609-2 Conarc 48 is a dual-classified welding electrode suitable for both SMAW (shielded metal arc welding / stick) and SAW (submerged arc welding) applications. Conarc designates a class of Lincoln electrodes formulated for combined SMAW/SAW use — the "48" designation indicates the 480 MPa (approximately 70 ksi) minimum yield strength classification of the deposit. Conarc 48 is classified under EN ISO 2560-A as E 42 2 B H5 (SMAW) and is the matching electrode for submerged arc welding procedures that require an all-position covered electrode alternative for gouging repairs, root-pass work, and field repair of SAW welds. In North American terminology, Conarc 48 corresponds broadly to an E7018-type basic low-hydrogen electrode with the matching chemistry for Lincoln's OP 122 TT submerged arc flux combination.

The 503609-2 part number indicates the 2 kg (approximately 4.4 lb) packaging size of 4.0 mm (approximately 5/32 in) diameter electrodes. This packaging format is commonly used in European, offshore, and export markets where 2 kg hermetically sealed boxes provide storage and handling flexibility in field environments. Lincoln Electric manufactures Conarc 48 in its European facilities under ISO 9001 and ISO 3834 quality management systems, meeting EN 13479 and comparable international quality standards.

AWS / EN Classification, Specifications & Mechanical Properties

• EN ISO Classification: E 42 2 B H5 per EN ISO 2560-A
• North American Equivalent: E7018 (basic low-hydrogen SMAW)
• SAW Classification: Designed for use with Lincoln OP 122 TT flux (EN ISO 14171-A: S 42 2 FB S4)
• Coating Type: Basic (iron powder / low-hydrogen)
• Hydrogen Level: H5 — maximum 5 mL diffusible hydrogen per 100 g deposited weld metal
• Part Number / Package: 503609-2 — 2 kg box
• Diameter: 4.0 mm (5/32 in equivalent)
• Minimum Tensile Strength: ≥480 MPa (≈69,600 psi)
• Minimum Yield Strength: ≥400 MPa (≈58,000 psi)
• Elongation: ≥22%
• CVN Impact (–20 °C / –4 °F): ≥47 J (34 ft-lbf) — "2" toughness designator

Best Applications for Lincoln Conarc 48

• Offshore and Marine Platform Fabrication: Jacket and topside structural steel fabrication where combined SMAW/SAW procedure qualifications are maintained. Conarc 48 is the go-to stick electrode when the production SAW line is interrupted and the certified WPS allows an SMAW electrode matched to the SAW combination.
• Shipbuilding and Naval Construction: Class society-approved SMAW electrode for ordinary and higher-tensile hull structural steel (ABS Grade A–EH, LR Grade A–EH, DNV GL Grade A–EH). The H5 classification satisfies most class society requirements for preheat reduction on Grade D and EH steels.
• Pressure Vessel and Boiler Fabrication (European and Export Markets): ASME and PED (Pressure Equipment Directive) fabrication in carbon and carbon-manganese steels to EN 10028-2 (P265GH, P295GH, P355GH grades) where EN ISO 2560-A-compliant SMAW filler metal is required by the welding procedure.
• SAW Root-Pass and Repair Welding: On submerged arc weld procedures using Lincoln's compatible flux/wire system, Conarc 48 serves as the qualified SMAW electrode for root passes (which cannot be made with SAW in tight groove geometries) and for repair grinding and re-welding of SAW weld defects.
• General Structural Steel Fabrication (EN 1011-1 applications): Fabrication of structural steel assemblies to EN 1090 execution class EXC2–EXC4 where WPS qualification requires EN ISO 2560-A-classified basic electrode.
• Heavy Equipment and Rail Car Fabrication: Crane booms, rail car chassis, and heavy transport frames in S355 structural steel (ASTM A572 Grade 50 equivalent) where EN or international standards govern the fabrication and basic SMAW electrodes are preferred for out-of-position joints that cannot be positioned for SAW.

How to Weld with Lincoln Conarc 48 — Settings, Gas & Technique

Electrode Conditioning

Conarc 48 is a basic (B) coating electrode — the primary moisture-sensitive type. Electrodes shipped in sealed hermetic packaging (factory-sealed vacuum foil) are ready to use without re-drying. Opened packages: if electrodes have been exposed to ambient air for more than 4 hours, re-dry at 300–350 °C (572–662 °F) for 1 hour before use. Maintain dried electrodes in a holding oven at 150 °C (302 °F). Do not re-dry more than twice — repeated baking degrades the coating.

Machine Settings (DCEP or AC)

• Polarity: DC+ (DCEP, reverse polarity) or AC. DC+ provides better penetration and a more stable arc for basic coatings; AC is acceptable where DC is not available.
• Amperage for 4.0 mm (5/32 in) electrode:
  • Flat position (1G, 1F): 140–200 A
  • Horizontal position (2G, 2F): 130–180 A
  • Vertical-up (3G, 3F): 110–160 A
  • Overhead (4G, 4F): 110–155 A
• Arc length: Short arc (~1× electrode diameter) is required for basic electrodes to avoid porosity — basic coatings are sensitive to long arc length, which disrupts the protective CO₂/CO gas shield generated by the coating.

Welding Technique for Basic Low-Hydrogen Electrodes

Use a drag technique or slight whip in the upward vertical position. For root passes in groove welds, maintain consistent travel speed and do not allow the puddle to get ahead of the electrode. Basic electrodes produce a fluid, self-leveling puddle that requires controlled travel to prevent excessive reinforcement. Clean slag with a chipping hammer and stainless wire brush before depositing the next pass — basic electrode slag is glassy and adherent and must be completely removed to prevent slag inclusions.

Storage and Handling of Lincoln Conarc 48 Electrodes

• Store sealed packages in a dry location at 50–120 °F (10–49 °C). Lincoln Conarc 48 is shipped in hermetically sealed, vacuum-foil packages that maintain H5 hydrogen classification indefinitely in unopened condition.
• Once opened: use within 4 hours without re-drying (at <80% RH). For humid environments (>80% RH) or where H5 must be maintained for critical welds, move immediately to a holding oven at 150 °C.
• Re-dry wet or damp electrodes at 300–350 °C for 1 hour maximum (max 2 re-dry cycles). Mark re-dried electrodes and track re-dry count.
• Do not use electrodes with cracked, flaking, or water-damaged coatings — damaged coatings produce porosity, high hydrogen, and erratic arc behavior.

Compatible Machines and Base Metals

Any DC or AC power source suitable for 4.0 mm basic SMAW electrodes at 110–200 A is suitable for Conarc 48. Lincoln Electric machines commonly paired with Conarc 48 in industrial and offshore settings:

• Lincoln Idealarc DC-400 and DC-600 (heavy-duty industrial DC)
• Lincoln Ranger 250 GXT and 305 G (engine-driven DC for field work)
• Lincoln Electric SAE-400 and SAE-600 (engine-driven for heavy field SMAW)
• Lincoln Power Wave AC/DC 1000 SD (SAW platform with AC output for Conarc 48 when SMAW fallback is needed)

Primary base metals:

• EN 10025-2 structural steel grades S235, S275, S355 (all delivery conditions)
• EN 10028-2 pressure vessel steels P265GH, P295GH, P355GH
• ABS, DNV GL, and LR Grade A, B, D, E, AH, DH, EH hull structural steel
• ASTM A36 and A572 Grade 50 (North American equivalent with procedure qualification)

Frequently Asked Questions — Lincoln Conarc 48 Electrode

Q1: What does "Conarc" mean in Lincoln Electric's product naming?
A: "Conarc" is Lincoln Electric's designation for dual-classified SMAW electrodes designed to be the covered-electrode companion to a specific submerged arc wire/flux combination. The name signifies that the electrode is "CO" (compatible) with the "N" (neutral) or "A" (active) "arc" (SMAW) process — in practice, it means a basic low-hydrogen electrode with chemistry matched to a Lincoln SAW flux/wire system, so that a single WPS can qualify both processes with consistent mechanical properties and AWS/EN classification parity.

Q2: What Lincoln submerged arc flux is Conarc 48 designed to match?
A: Conarc 48 is the SMAW complement to Lincoln's OP 122 TT flux combined with OK Autrod 12.22 or equivalent S2 wire. The OP 122 TT / OK Autrod 12.22 combination is classified EN ISO 14171-A: S 42 2 FB S4, matching the Conarc 48 deposit chemistry and mechanical properties for combined SMAW/SAW WPS qualification. This is commonly specified for offshore structural steel and shipbuilding where single WPS qualification covering both processes is administratively efficient.

Q3: Is Conarc 48 (503609-2) available in North America?
A: Conarc 48 is primarily a European and international market product. In North America, the equivalent basic low-hydrogen SMAW electrode is Lincoln Electric's Excalibur 7018 or similar E7018 products. Conarc 48 can be ordered through Lincoln Electric distributors with international supply capabilities or directly through Lincoln's industrial supply network. WeldingMart.com can assist with availability and lead time for this product.

Q4: Can Conarc 48 be used for welding offshore structural steel without preheat?
A: The H5 hydrogen classification of Conarc 48 enables reduced preheat requirements compared to H10 or H16 electrodes for comparable steels per EN 1011-2 (IIW carbon equivalent method). For S355 structural steel up to 25 mm (1 in) thickness with carbon equivalent CE ≤0.43, preheat may be reduced to ambient temperature (≥5 °C / 41 °F) with H5 electrodes. Thicker sections or higher carbon equivalent still require preheat — verify using EN 1011-2 tables or the Lincoln Electric preheat calculator for the specific heat number and thickness.

Q5: What is the redrying procedure if Conarc 48 electrodes have been left out overnight?
A: If electrodes have been exposed to ambient air (<80% RH) for 4–8 hours, re-dry at 300 °C (572 °F) for 60 minutes in a certified electrode oven. For exposure longer than 8 hours, or in high-humidity environments (>80% RH), increase drying to 350 °C (662 °F) for 60–90 minutes. Do not exceed 400 °C (752 °F) — excessively high re-drying temperature damages the silicate binder in the basic coating and causes coating delamination, which renders the electrodes unusable. Do not re-dry more than twice.

Q6: What is the "2" toughness designator in the EN ISO 2560-A classification?
A: The "2" in E 42 2 B H5 indicates the minimum average Charpy V-notch (CVN) impact energy of ≥47 J (34 ft-lbf) at a test temperature of –20 °C (–4 °F). This satisfies the requirements for Grade D and Grade DH (high-strength) hull structural steel welding per major class societies (ABS, DNV GL, LR) for service in temperate and cold-climate environments. For the EN 1090/EN 1993 steel structure execution class requirements, "2" designation satisfies EXC3 and EXC4 impact toughness requirements for S355 structural steel.

Q7: How does Conarc 48 compare to Lincoln Excalibur 7018 for structural steel welding?
A: Both are basic low-hydrogen electrodes with similar 70 ksi class deposits. Key differences: Conarc 48 is EN ISO 2560-A classified and packaged in 2 kg hermetic boxes for European/international markets; Excalibur 7018 is AWS A5.1 classified and packaged in standard North American tube formats. Conarc 48 is specifically matched to Lincoln's SAW flux/wire combination for dual-process WPS qualification, while Excalibur 7018 is a standalone SMAW product not specifically matched to a SAW combination.