Welding is a cornerstone of industries from construction to aerospace, where the strength and durability of a joint can determine the success of a project—or its failure. Selecting the appropriate electrode or filler metal is a critical decision that impacts weld quality, safety, and longevity. Whether you’re joining carbon steel for a pipeline, aluminum for an aircraft, or exotic alloys for a chemical reactor, the filler must align with the base metal’s properties and the welding process’s requirements. A mismatch can lead to cracks, corrosion, or weak welds, risking costly repairs or catastrophic consequences.
This blog post provides a detailed guide to choosing welding electrodes and filler metals for a wide range of alloys, including carbon steel, low alloy steel, stainless steel, aluminum, copper alloys, nickel alloys, cast iron, brass, bronze, and special alloys. We’ve expanded the scope to include emerging alloys like advanced aluminum grades and super duplex stainless steels, drawing on industry standards from the American Welding Society (AWS) and insights from leading manufacturers like Lincoln Electric and ESAB. Our comprehensive tables list recommended fillers for SMAW (stick), GMAW (MIG), GTAW (TIG), and FCAW (flux-cored), along with applications and practical notes to guide welders, engineers, and enthusiasts.
The Importance of Filler Metal Selection
Filler metals are the binding agents in welding, filling gaps and fusing base metals to create a cohesive joint. Choosing the right filler ensures:
- Chemical Compatibility: Matches the base metal’s composition to prevent issues like galvanic corrosion.
- Mechanical Integrity: Delivers strength, toughness, or ductility suited to the application’s demands.
- Process Suitability: Works seamlessly with welding methods like MIG, TIG, or stick.
- Environmental Resistance: Withstands conditions like high temperatures, corrosion, or cryogenic stress.
For instance, welding a carbon steel pressure vessel with an incompatible filler could cause hydrogen-induced cracking, while using the wrong nickel alloy filler in a chemical plant might lead to premature corrosion. Standards like AWS A5.x (e.g., AWS A5.1) and ISO 14343 provide classifications to ensure fillers meet these needs, making selection a science as much as an art.
Factors to Consider in Filler Metal Selection
Before exploring the tables, here are key factors to guide your choice:
- Base Metal Type: Identify the alloy, such as ASTM A36 steel or 6061 aluminum, to match composition.
- Welding Process: SMAW electrodes differ from GMAW wires or GTAW rods in design and application.
- Service Conditions: Consider temperature, corrosion, or fatigue (e.g., marine vs. high-heat environments).
- Joint Design: Thick sections need high-deposition fillers; thin sheets require precision.
- Code Compliance: Adhere to standards like ASME BPVC or AWS D1.1.
- Welding Position: Some fillers excel in vertical or overhead positions.
- Cost vs. Quality: Balance budget with performance, especially for critical welds.
With these factors in mind, let’s dive into the selection charts, covering both traditional and emerging alloys to provide a comprehensive resource.
Filler Metal Selection Charts
The following tables recommend electrodes and filler metals for various alloys, based on AWS classifications and industry practices. Each table includes base metal grades, recommended fillers for SMAW, GMAW, GTAW, and FCAW, typical applications, and notes for practical guidance. We’ve included newer alloys like advanced aluminum grades and super duplex stainless steels to reflect modern welding demands.
Welding Electrode Selector
Carbon Steel
Carbon steels, known for their versatility, are used in structures, pipelines, and machinery. Grades like ASTM A572 Gr. 50 offer higher strength for modern applications.
The selection of consumables is based on AWS standards (e.g., AWS A5.1 for SMAW, A5.5 for low-alloy electrodes, A5.17 for SAW) and industry practices, matching the carbon content, strength, and weldability of each grade. SMAW electrodes focus on low-hydrogen options (e.g., E7018) for most grades to minimize cracking, while SAW electrodes (e.g., F7A6-EM12K) are chosen for high-productivity welding of thicker sections.
| Base Metal Grade | GMAW Wire | GTAW Rod | SMAW Electrode | SAW Electrode | Applications | Notes |
|---|---|---|---|---|---|---|
| A36 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Structural beams, bridges | Low carbon; excellent weldability; no preheat needed |
| 1018 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Shafts, machine parts | Low carbon; clean surface for best results |
| 1020 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Automotive components | Low carbon; good for general welding |
| 1045 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Gears, axles | Medium carbon; preheat 200-300°C to avoid cracking |
| 1060 | ER309L | ER309L | E309L-16 | F309L-EC1 | Cutting tools, springs | High carbon; preheat 250-350°C; austenitic filler for crack resistance |
| A516 Gr. 70 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Pressure vessels | Low carbon; use low-hydrogen consumables |
| A572 Gr. 50 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Bridges, construction | Low carbon; high strength; good weldability |
| AISI 1010 | ER70S-6 | ER70S-2 | E6013 | F7A2-EM12K | Sheet metal, pipes | Ultra-low carbon; highly weldable; E6013 for thin sections |
| AISI 1030 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Forgings, machinery | Medium carbon; preheat 150-200°C |
| AISI 1050 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Shafts, couplings | Medium carbon; preheat 200-250°C |
| AISI 1080 | ER309L | ER309L | E309L-16 | F309L-EC1 | Knives, wear plates | High carbon; preheat 300-400°C; slow cooling |
| API 5L Gr. B | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Pipelines | Low carbon; excellent for butt welds |
| API 5L X42 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Gas pipelines | Low carbon; control heat input |
| API 5L X52 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Oil pipelines | Low carbon; use low-hydrogen fillers |
| API 5L X60 | ER80S-Ni1 | ER80S-Ni1 | E8018-C1 | F8A4-ENi1 | High-pressure pipelines | Medium strength; preheat may be needed |
| AISI 1008 | ER70S-6 | ER70S-2 | E6013 | F7A2-EM12K | Wire products, nails | Ultra-low carbon; minimal prep; E6013 for light welds |
| AISI 1025 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Automotive frames | Low carbon; good ductility |
| AISI 1040 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Crankshafts | Medium carbon; preheat 150-200°C |
| AISI 1070 | ER309L | ER309L | E309L-16 | F309L-EC1 | Springs, blades | High carbon; preheat 250-350°C |
| ASTM A106 Gr. B | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Boiler pipes | Low carbon; seamless welding |
| ASTM A53 Gr. B | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Water lines | Low carbon; good for structural welds |
| AISI 1015 | ER70S-6 | ER70S-2 | E7018 | F7A2-EM12K | Fasteners, rods | Low carbon; clean welds easily achieved |
| AISI 1035 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Machine parts | Medium carbon; preheat 150-200°C |
| AISI 1095 | ER309L | ER309L | E309L-16 | F309L-EC1 | Cutting tools | High carbon; preheat 300-400°C; post-weld heat treatment |
| AISI 1141 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | High-strength bolts | Medium carbon; sulfur may cause cracking |
| AISI 1144 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Shafts, screws | Free-machining; avoid welding if possible due to sulfur |
| ASTM A500 Gr. B | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Structural tubing | Low carbon; good for hollow sections |
| ASTM AISI 1022 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Rivets, screws | Low carbon; excellent weldability |
| AISI 1043 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Gears, shafts | Medium carbon; preheat 200-250°C |
| AISI 1065 | ER309L | ER309L | E309L-16 | F309L-EC1 | Springs, dies | High carbon; preheat 250-350°C |
| ASTM A516 Gr. 60 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Storage tanks | Low carbon; low-hydrogen process preferred |
| ASTM AISI 1012 | ER70S-6 | ER70S-2 | E6013 | F7A2-EM12K | Thin sheets | Ultra-low carbon; E6013 for thin sections |
| AISI 1055 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Axles, tools | Medium carbon; preheat 200-300°C |
| AISI 1085 | ER309L | ER309L | E309L-16 | F309L-EC1 | Wear-resistant parts | High carbon; preheat 300-400°C |
| API 5L X46 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Pipelines | Low carbon; control interpass temp |
| API 5L X65 | ER80S-Ni1 | ER80S-Ni1 | E8018-C1 | F8A4-ENi1 | Offshore pipelines | Higher strength; preheat 100-150°C |
| ASTM AISI 1006 | ER70S-6 | ER70S-2 | E6013 | F7A2-EM12K | Wire mesh | Ultra-low carbon; excellent weldability |
| AISI 1026 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Tubing, fittings | Low carbon; good for seamless welds |
| AISI 1038 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Crankshafts | Medium carbon; preheat 150-200°C |
| AISI 1075 | ER309L | ER309L | E309L-16 | F309L-EC1 | Blades, springs | High carbon; preheat 250-350°C |
| ASTM A285 Gr. C | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Boiler plates | Low carbon; good for pressure vessels |
| ASTM AISI 1017 | ER70S-6 | ER70S-2 | E7018 | F7A2-EM12K | Structural parts | Low carbon; clean surface critical |
| AISI 1049 | ER80S-D2 | ER80S-D2 | E8018-C3 | F8A4-EG | Gears, couplings | Medium carbon; preheat 200-250°C |
| AISI 1090 | ER309L | ER309L | E309L-16 | F309L-EC1 | Tools, dies | High carbon; preheat 300-400°C |
| ASTM A656 Gr. 50 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Truck frames | Low carbon; high-strength low-alloy |
| ASTM AISI 1021 | ER70S-6 | ER70S-2 | E7018 | F7A6-EM12K | Forgings | Low carbon; good weldability |
| AISI 1037 | ER70S-6 | ER70S-6 | E7018 | F7A6-EM12K | Machine components | Medium carbon; preheat 150-200°C |
| AISI 1084 | ER309L | ER309L | E309L-16 | F309L-EC1 | Cutting edges | High carbon; preheat 300-400°C |
| ASTM AISI 1005 | ER70S-6 | ER70S-2 | E6013 | F7A2-EM12K | Thin wires | Ultra-low carbon; highly weldable |
| AISI 1064 | ER309L | ER309L | E309L-16 | F309L-EC1 | Springs, tools | High carbon; preheat 250-350°C |
Additional Notes:
- SMAW Electrodes: E7018 is the go-to low-hydrogen electrode for most low and medium carbon steels due to its versatility and crack resistance. E6013 is used for thin, low-carbon sections where ease of use matters. For high carbon steels, E309L-16 provides austenitic welds to reduce cracking, though strength may not match the base metal.
- SAW Electrodes: F7A6-EM12K is standard for low carbon steels, offering high deposition rates for thick sections. For higher strength or alloyed grades (e.g., API X65), F8A4-ENi1 or similar are used to match mechanical properties. Flux choice (e.g., neutral or active) affects weld quality—consult specs for critical applications.
- Preheat and PWHT: Medium carbon (0.3-0.6% C) and high carbon (>0.6% C) grades require preheat (noted in table) to prevent HAZ cracking. PWHT may be needed for high carbon steels or thick sections to reduce residual stresses.
- Free-Machining Grades (e.g., 1141, 1144): High sulfur/phosphorus content increases cracking risk. Use low-hydrogen consumables and consider avoiding welding if possible.
- Carbon Equivalent (CE): For grades like API X60/X65, calculate CE (C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15) to determine preheat. CE > 0.4 typically requires preheat.
| Base Metal Grade | SMAW Electrode | GMAW Wire | GTAW Rod | FCAW Wire | Applications | Notes |
|---|---|---|---|---|---|---|
| ASTM A36 | E7018 | ER70S-6 | ER70S-2 | E71T-1 | Building frames, bridges | E7018 for low hydrogen; ER70S-6 for general MIG welding. |
| ASTM A516 Gr. 70 | E7016 | ER70S-3 | ER70S-3 | E70T-5 | Pressure vessels | E7016 for clean surfaces; ER70S-3 for smooth TIG welds. |
| ASTM A572 Gr. 50 | E7018 | ER70S-6 | ER70S-2 | E71T-1 | High-rise structures | Matches 50 ksi yield; preheat for thick sections. |
| API 5L Gr. B | E6010 (root), E7018 (fill) | ER70S-4 | ER70S-2 | E71T-8 | Pipelines | E6010 for root penetration; ER70S-4 for multi-pass. |
| API 5L X65 | E8018-C3 | ER80S-Ni1 | ER80S-Ni1 | E81T1-Ni1 | Gas pipelines | Matches 65 ksi yield; use low hydrogen fillers. |
| API 5L X70 | E9018-G | ER90S-G | ER90S-G | E91T1-K2 | High-pressure pipelines | For 70 ksi yield; cellulosic E8010-P1 for root in pipeline welding. |
Low Alloy Steel
Low alloy steels, with added elements like chromium or molybdenum, offer enhanced strength and heat resistance, used in power plants and heavy equipment.
| Base Metal Grade | SMAW Electrode | GMAW Wire | GTAW Rod | FCAW Wire | Applications | Notes |
|---|---|---|---|---|---|---|
| AISI 4130 | E8018-B2 | ER80S-D2 | ER80S-D2 | E81T1-B2 | Oilfield equipment | Matches Cr-Mo; preheat to 200°C to avoid cracks. |
| ASTM A387 Gr. 11 | E7018-A1 | ER80S-B2 | ER80S-B2 | E81T1-B2 | Boiler plates | For 1.25% Cr – 0.5% Mo; post-weld heat treatment (PWHT) often needed. |
| ASTM A387 Gr. 22 | E8018-B3 | ER90S-B3 | ER90S-B3 | E91T1-B3 | High-temperature vessels | For 2.25% Cr – 1% Mo; PWHT critical. |
| ASTM A335 P22 | E8018-B3 | ER90S-B3 | ER90S-B3 | E91T1-B3 | Power plant piping | Matches high-temperature properties; control cooling. |
| ASTM A588 | E8018-W | ER80S-G | ER80S-G | E81T1-W | Weathering steel bridges | For Corten steel; resists atmospheric corrosion. |
| ASTM A514 | E11018-M | ER110S-1 | ER110S-1 | E110T5-K4 | Mining equipment | High-strength; PWHT to reduce residual stress. |
Low alloy steels are designed for enhanced strength, toughness, or resistance to specific environments (e.g., high temperature, corrosion), and electrode selection is based on matching the base metal’s composition, mechanical properties, and service conditions. Electrode recommendations prioritize weld integrity, avoiding issues like cracking or embrittlement.
| Low Alloy Steel Grade | Category | Recommended Welding Electrode |
|---|---|---|
| AISI 4130 | Cr-Mo, Q&T | E8018-B2, E7018-A1 |
| AISI 4140 | Cr-Mo, Q&T | E9018-M, E10018-D2 |
| AISI 4340 | Ni-Cr-Mo, Q&T | E10018-D2, E11018-M |
| ASTM A204 Gr. A | Mo Steel | E7018-A1 |
| ASTM A204 Gr. B | Mo Steel | E7018-A1 |
| ASTM A204 Gr. C | Mo Steel | E7018-A1 |
| ASTM A335 P1 | Cr-Mo | E7018-A1 |
| ASTM A335 P11 | Cr-Mo (1.25Cr-0.5Mo) | E8018-B2 |
| ASTM A335 P12 | Cr-Mo (1Cr-0.5Mo) | E8018-B2 |
| ASTM A335 P22 | Cr-Mo (2.25Cr-1Mo) | E9018-B3 |
| ASTM A335 P5 | Cr-Mo (5Cr-0.5Mo) | E8018-B6 |
| ASTM A335 P9 | Cr-Mo (9Cr-1Mo) | E9018-B9 |
| ASTM A387 Gr. 11 | Cr-Mo (1.25Cr-0.5Mo) | E8018-B2 |
| ASTM A387 Gr. 12 | Cr-Mo (1Cr-0.5Mo) | E8018-B2 |
| ASTM A387 Gr. 22 | Cr-Mo (2.25Cr-1Mo) | E9018-B3 |
| ASTM A387 Gr. 5 | Cr-Mo (5Cr-0.5Mo) | E8018-B6 |
| ASTM A387 Gr. 9 | Cr-Mo (9Cr-1Mo) | E9018-B9 |
| ASTM A514 Gr. B | Q&T, High-Strength | E11018-M, E10018-D2 |
| ASTM A514 Gr. E | Q&T, High-Strength | E11018-M |
| ASTM A514 Gr. F | Q&T, High-Strength | E11018-M |
| ASTM A516 Gr. 60 | Carbon-Mn | E7018 |
| ASTM A516 Gr. 70 | Carbon-Mn | E7018 |
| ASTM A517 Gr. A | Q&T, High-Strength | E11018-M |
| ASTM A517 Gr. B | Q&T, High-Strength | E11018-M |
| ASTM A533 Gr. B | Mn-Mo-Ni | E9018-M, E8018-G |
| ASTM A588 Gr. A | Weathering Steel | E8018-W |
| ASTM A588 Gr. B | Weathering Steel | E8018-W |
| ASTM A588 Gr. C | Weathering Steel | E8018-W |
| ASTM A633 Gr. C | Normalized, HSLA | E8018-C3 |
| ASTM A633 Gr. D | Normalized, HSLA | E8018-C3 |
| ASTM A633 Gr. E | Normalized, HSLA | E10018-D2 |
| ASTM A710 Gr. A | HSLA, Precipitation-Hardened | E8018-C3 |
| ASTM A710 Gr. B | HSLA, Precipitation-Hardened | E8018-C3 |
| SAE 6150 | Cr-V, Q&T | E9018-M |
| SAE 8620 | Ni-Cr-Mo, Carburizing | E8018-C3 |
| SAE 8630 | Ni-Cr-Mo, Q&T | E9018-M |
| SAE 8640 | Ni-Cr-Mo, Q&T | E10018-D2 |
| HY-80 | Ni-Cr-Mo, Q&T (Military) | E11018-M |
| HY-100 | Ni-Cr-Mo, Q&T (Military) | E11018-M |
| ASTM A737 Gr. B | HSLA, Pressure Vessel | E8018-C3 |
| ASTM A737 Gr. C | HSLA, Pressure Vessel | E8018-C3 |
| ASTM A302 Gr. A | Mn-Mo, Pressure Vessel | E7018-A1 |
| ASTM A302 Gr. B | Mn-Mo, Pressure Vessel | E8018-G |
| ASTM A508 Gr. 1 | Mn-Mo-Ni, Forging | E8018-G |
| ASTM A508 Gr. 2 | Mn-Mo-Ni, Forging | E9018-M |
| ASTM A508 Gr. 3 | Mn-Mo-Ni, Forging | E9018-M |
| ASTM A543 Gr. B | Ni-Cr-Mo, Q&T | E11018-M |
| ASTM A543 Gr. C | Ni-Cr-Mo, Q&T | E11018-M |
| ASTM A678 Gr. A | Q&T, HSLA | E9018-M |
| ASTM A678 Gr. B | Q&T, HSLA | E10018-D2 |
Notes:
- Electrode Designations:
- The “E” prefix indicates an electrode for SMAW.
- The first two digits (e.g., 70, 80, 90, 100, 110) denote minimum tensile strength in ksi (e.g., E7018 = 70 ksi).
- Suffixes like -A1, -B2, -B3, -C3, -D2, -M, -W indicate alloying elements or specific properties:
- -A1: Mo addition for creep resistance (e.g., A204, P1).
- -B2, -B3, -B6, -B9: Cr-Mo for high-temperature service (e.g., P11, P22, P5, P9).
- -C3: Ni for toughness in low temperatures (e.g., A633, A710).
- -D2: Mn-Mo for high strength (e.g., A514, 4340).
- -M: Ni-Cr-Mo for high-strength, quenched-and-tempered steels (e.g., HY-80, 4140).
- -W: Weathering steel electrodes with Ni-Cu for corrosion resistance (e.g., A588).
- The suffix “-18” indicates low-hydrogen coating, critical for low alloy steels to prevent hydrogen-induced cracking.
- Selection Considerations:
- Cr-Mo Steels (e.g., P11, P22): Use matching Cr-Mo electrodes (E8018-B2, E9018-B3) for high-temperature strength and creep resistance.
- High-Strength Low Alloy (HSLA) Steels (e.g., A514, A633): Require low-hydrogen, high-tensile electrodes (E10018, E11018) to match strength and toughness.
- Weathering Steels (e.g., A588): Use E8018-W to ensure corrosion resistance in atmospheric conditions.
- Mn-Mo and Ni-Mo Steels (e.g., A533, A508): Electrodes like E8018-G or E9018-M provide toughness for pressure vessel applications.
- Q&T Steels (e.g., 4140, HY-80): High-strength electrodes (E10018-D2, E11018-M) prevent weld metal undermatching and cracking.
- Welding Precautions:
- Preheat: Most low alloy steels require preheat (100–400°C, depending on grade and thickness) to reduce residual stresses and prevent cracking.
- Post-Weld Heat Treatment (PWHT): Common for Cr-Mo grades (e.g., P22, P9) and pressure vessel steels to relieve stresses and restore properties.
- Low-Hydrogen Practice: Store electrodes in ovens (120–150°C) to avoid moisture, and use low-hydrogen techniques to minimize cold cracking.
- Dissimilar Welding: For joining low alloy steel to carbon steel, E7018 or E8018-C3 are often used; for stainless steel, E309-16 is typical.
- Limitations:
- Some grades (e.g., A514, HY-80) are sensitive to heat input; use stringer beads and avoid excessive weaving.
- High-strength grades require precise control of cooling rates to maintain properties.
Stainless Steel
Stainless steels, valued for corrosion resistance, are common in food processing, marine, and chemical industries. Newer grades like 2507 enhance performance.
| Stainless Steel Grade | Type | Recommended Welding Electrode |
|---|---|---|
| 201 | Austenitic | E308-16, E309-16 |
| 202 | Austenitic | E308-16, E309-16 |
| 301 | Austenitic | E308-16, E308L-16 |
| 302 | Austenitic | E308-16, E308L-16 |
| 304 | Austenitic | E308-16, E308L-16 |
| 304L | Austenitic | E308L-16 |
| 304H | Austenitic | E308H-16 |
| 305 | Austenitic | E308-16, E308L-16 |
| 309 | Austenitic | E309-16, E309L-16 |
| 309L | Austenitic | E309L-16 |
| 310 | Austenitic | E310-16 |
| 310S | Austenitic | E310-16 |
| 316 | Austenitic | E316-16, E316L-16 |
| 316L | Austenitic | E316L-16 |
| 316H | Austenitic | E316H-16 |
| 317 | Austenitic | E317-16, E317L-16 |
| 317L | Austenitic | E317L-16 |
| 321 | Austenitic | E347-16 |
| 347 | Austenitic | E347-16 |
| 348 | Austenitic | E347-16 |
| 403 | Martensitic | E410-16 |
| 405 | Ferritic | E430-16, E309-16 |
| 409 | Ferritic | E309-16, E309L-16 |
| 410 | Martensitic | E410-16 |
| 410S | Ferritic | E410-16, E309L-16 |
| 416 | Martensitic | E312-16 |
| 420 | Martensitic | E420-16, E410-16 |
| 430 | Ferritic | E430-16, E309-16 |
| 430F | Ferritic | E430-16, E309-16 |
| 434 | Ferritic | E309-16, E316-16 |
| 436 | Ferritic | E309-16, E316-16 |
| 439 | Ferritic | E309-16, E308L-16 |
| 440A | Martensitic | E312-16, E410-16 |
| 440B | Martensitic | E312-16, E410-16 |
| 440C | Martensitic | E312-16, E410-16 |
| 441 | Ferritic | E309-16, E308L-16 |
| 444 | Ferritic | E316L-16, E309Mo-16 |
| 2205 (S31803) | Duplex | E2209-16 |
| 2507 (S32750) | Duplex | E2594-16 |
| 2304 (S32304) | Duplex | E2209-16 |
| 255 (S32550) | Duplex | E2553-16 |
| 15-5PH (S15500) | Precipitation-Hardening | E630-16 |
| 17-4PH (S17400) | Precipitation-Hardening | E630-16 |
| 17-7PH (S17700) | Precipitation-Hardening | E308-16, E309-16 |
| 904L (N08904) | Austenitic | E385-16 |
| 254 SMO (S31254) | Austenitic | E385-16, E309Mo-16 |
| AL-6XN (N08367) | Austenitic | E309Mo-16, E385-16 |
| 330 (N08330) | Austenitic | E330-16 |
| 253 MA (S30815) | Austenitic | E309-16, E310-16 |
| 314 | Austenitic | E310-16 |
Notes:
- Electrode Designations:
- The “E” prefix indicates an electrode for arc welding (SMAW).
- The number (e.g., 308, 316) matches the base metal’s alloy composition.
- “L” denotes low carbon (e.g., E308L-16) to reduce carbide precipitation and improve corrosion resistance.
- “H” indicates higher carbon for high-temperature strength (e.g., E308H-16).
- The suffix “-16” or “-15” refers to the coating type and polarity (-16 for AC or DC electrode positive, -15 for DC electrode positive only). Most recommendations here use -16 for versatility.
- Selection Considerations:
- Austenitic Grades (e.g., 304, 316): Use matching electrodes (E308, E316) or low-carbon variants (E308L, E316L) to prevent intergranular corrosion.
- Ferritic Grades (e.g., 430, 409): Often welded with austenitic electrodes (E309, E308L) to improve weld toughness, as ferritic electrodes are less common.
- Martensitic Grades (e.g., 410, 420): Require matching electrodes (E410) or high-alloy electrodes (E312) for crack resistance.
- Duplex Grades (e.g., 2205): Use duplex-specific electrodes (E2209, E2594) to balance austenite-ferrite phases.
- Precipitation-Hardening Grades (e.g., 17-4PH): Use electrodes like E630 to match the alloy’s strength and corrosion properties.
- Dissimilar Welding:
- For welding stainless steel to carbon steel or dissimilar stainless grades, E309-16 or E309L-16 are commonly used due to their ability to handle dilution and prevent cracking.
- Welding Tips:
- Ensure proper joint preparation (clean surfaces, no contaminants).
- Use the lowest possible current to avoid overheating, which can degrade corrosion resistance.
- Store electrodes in a dry environment to prevent moisture pickup, which can cause porosity.
| Base Metal Grade | SMAW Electrode | GMAW Wire | GTAW Rod | FCAW Wire | Applications | Notes |
|---|---|---|---|---|---|---|
| 304/304L | E308L-16 | ER308L | ER308L | E308LT-1 | Kitchen equipment | Low carbon prevents carbide precipitation; versatile filler. |
| 316/316L | E316L-16 | ER316L | ER316L | E316LT-1 | Marine tanks | Molybdenum for pitting resistance; match composition. |
| 321 | E347-16 | ER321 | ER321 | E347T-1 | Aircraft exhausts | Titanium-stabilized for high temperatures; E347 as alternative. |
| 347 | E347-16 | ER347 | ER347 | E347T-1 | Refinery piping | Niobium-stabilized; resists intergranular corrosion. |
| 2205 Duplex | E2209-16 | ER2209 | ER2209 | E2209T-1 | Offshore platforms | Balances ferrite/austenite; nitrogen shielding for MIG. |
| 2507 Super Duplex | E2594-16 | ER2594 | ER2594 | E2594T-1 | Chemical processing | High PREN (>40) for extreme corrosion resistance. |
| 310 | E310-16 | ER310 | ER310 | N/A | Furnace components | High chromium for oxidation resistance at high temperatures. |
Aluminum
Aluminum alloys, lightweight and corrosion-resistant, are used in automotive, aerospace, and marine applications. New grades like 6013 offer improved weldability.
| Base Metal Grade | GMAW Wire | GTAW Rod | Applications | Notes |
|---|---|---|---|---|
| 6061 | ER4043 | ER4043 | Vehicle frames | Silicon-based; good for general welding; clean oxide layer. |
| 5083 | ER5356 | ER5356 | Ship hulls | Magnesium-based; high strength for marine use. |
| 5052 | ER5356 | ER5356 | Fuel tanks | Welds well with 6061; corrosion-resistant. |
| 2024 | ER2319 | ER2319 | Aircraft skins | Copper-based; matches composition; preheat thin sections. |
| 7075 | ER5356 | ER5356 | Aerospace fittings | Crack-sensitive; weld with caution; ER5356 for strength. |
| 6013 | ER4043 | ER4043 | Automotive panels | Newer alloy; ER4043 for weldability; emerging in lightweight structures. |
Copper and Copper Alloys
Copper alloys, including brass and bronze, offer conductivity and corrosion resistance for electrical and marine uses. Silicon bronze is versatile for dissimilar welds.
| Base Metal Grade | SMAW Electrode | GMAW Wire | GTAW Rod | Applications | Notes |
|---|---|---|---|---|---|
| C11000 (Pure Copper) | ECu | ERCu | ERCu | Busbars | Deoxidized copper; GTAW for precision; argon shielding. |
| C70600 (Cu-Ni 90/10) | ECuNi | ERCuNi | ERCuNi | Heat exchangers | Matches nickel for seawater resistance; clean surfaces. |
| C71500 (Cu-Ni 70/30) | ECuNi | ERCuNi | ERCuNi | Desalination pipes | Higher nickel; control heat to avoid porosity. |
| C26000 (Cartridge Brass) | ECuSi | ERCuSi-A | ERCuSi-A | Plumbing fixtures | Silicon bronze minimizes zinc fuming; versatile filler. |
| C83600 (Tin Bronze) | ECuSn-C | ERCuSn-A | ERCuSn-A | Bearings | Tin bronze for matching alloy; preheat thick sections. |
| C95400 (Al Bronze) | ECuAl-A2 | ERCuAl-A2 | ERCuAl-A2 | Propellers | Aluminum bronze for wear resistance; avoid overheating. |
| C65500 (Silicon Bronze) | ECuSi | ERCuSi-A | ERCuSi-A | Sculptures | Used for brass, bronze, or dissimilar welds; low fuming. |
| Alloy Grade | Category | Recommended Welding Electrode |
|---|---|---|
| C11000 (Electrolytic Cu) | Pure Copper | ECu |
| C10100 (OFHC Copper) | Oxygen-Free Copper | ECu |
| C12200 (Phosphorized Cu) | Deoxidized Copper | ECu |
| C14500 (Tellurium Cu) | Free-Machining Copper | ECu |
| C18200 (Cr Copper) | Chromium Copper | ECuCr |
| C19400 (Cu-Fe-P) | High-Strength Copper | ECu |
| C26000 (Cartridge Brass) | Cu-Zn (Brass) | ECuSi, ECuSn-A |
| C26800 (Yellow Brass) | Cu-Zn (Brass) | ECuSi, ECuSn-A |
| C36000 (Free-Cut Brass) | Cu-Zn-Pb (Brass) | ECuSi |
| C46400 (Naval Brass) | Cu-Zn-Sn (Brass) | ECuSn-C |
| C51000 (Phosphor Bronze) | Cu-Sn-P (Bronze) | ECuSn-A |
| C52100 (Phosphor Bronze) | Cu-Sn-P (Bronze) | ECuSn-A |
| C61418 (Al Bronze) | Cu-Al-Fe-Mn | ECuAl-A2 |
| C63000 (Ni-Al Bronze) | Cu-Al-Ni-Fe | ECuAl-A2 |
| C70600 (Cu-Ni 90/10) | Copper-Nickel | ECuNi |
| C71500 (Cu-Ni 70/30) | Copper-Nickel | ECuNi |
| C75200 (Nickel Silver) | Cu-Ni-Zn | ECuNi |
| C81100 (Silicon Bronze) | Cu-Si | ECuSi |
| C83600 (Leaded Bronze) | Cu-Sn-Pb-Zn | ECuSn-C |
| C93200 (Bearing Bronze) | Cu-Sn-Pb | ECuSn-C |
| Monel 400 (N04400) | Ni-Cu | ENiCu-7 |
| Monel K500 (N05500) | Ni-Cu (Age-Hardened) | ENiCu-7 |
| Inconel 600 (N06600) | Ni-Cr-Fe | ENiCrFe-3 |
| Inconel 625 (N06625) | Ni-Cr-Mo-Nb | ENiCrMo-3 |
| Inconel 718 (N07718) | Ni-Cr-Fe-Nb (Age-Hardened) | ENiCrFe-3 |
| Incoloy 800 (N08800) | Ni-Cr-Fe | ENiCrFe-2 |
| Incoloy 825 (N08825) | Ni-Fe-Cr-Mo | ENiCrMo-3 |
| Hastelloy C-276 (N10276) | Ni-Mo-Cr | ENiCrMo-4 |
| Hastelloy C-22 (N06022) | Ni-Cr-Mo-W | ENiCrMo-10 |
| Hastelloy X (N06002) | Ni-Cr-Fe-Mo | ENiCrMo-2 |
| Alloy 20 (N08020) | Ni-Cr-Mo-Fe | ENiCrMo-3 |
| Nickel 200 (N02200) | Commercially Pure Nickel | ENi-1 |
| Nickel 201 (N02201) | Low-Carbon Nickel | ENi-1 |
| Cupronickel C71640 | Cu-Ni-Fe-Mn | ECuNi |
| Aluminum Bronze C95400 | Cu-Al-Fe | ECuAl-A2 |
| Silicon Bronze C65500 | Cu-Si-Mn | ECuSi |
| Tin Bronze C90300 | Cu-Sn-Zn | ECuSn-A |
| Leaded Tin Bronze C92700 | Cu-Sn-Pb | ECuSn-C |
| Admiralty Brass C44300 | Cu-Zn-Sn | ECuSn-A |
| Manganese Bronze C86300 | Cu-Zn-Mn-Fe | ECuMn-A |
| Nickel Aluminum Bronze C95800 | Cu-Al-Ni-Fe | ECuAl-A2 |
| Beryllium Copper C17200 | Cu-Be | ECu |
| Phosphor Copper C18980 | Cu-P | ECu |
| Red Brass C23000 | Cu-Zn | ECuSi |
| Gilding Metal C22000 | Cu-Zn | ECuSi |
| Muntz Metal C28000 | Cu-Zn | ECuSi |
| Inconel 690 (N06690) | Ni-Cr-Fe | ENiCrFe-7 |
| Hastelloy B-3 (N10675) | Ni-Mo | ENiMo-10 |
| Nimonic 75 (N06075) | Ni-Cr-Ti | ENiCrFe-3 |
| Rene 41 (N07041) | Ni-Cr-Co-Mo | ENiCrFe-3 |
| Waspaloy (N07001) | Ni-Cr-Co-Mo-Ti | ENiCrFe-3 |
Notes:
- Electrode Designations:
- ECu: Copper electrodes for pure and deoxidized copper, ensuring good conductivity.
- ECuSn-A/C: Tin-bronze electrodes for bronzes and brasses, providing strength and corrosion resistance.
- ECuSi: Silicon-bronze electrodes for brasses and copper alloys, offering good flow and versatility.
- ECuAl-A2: Aluminum-bronze electrodes for high-strength copper-aluminum alloys.
- ECuNi: Copper-nickel electrodes for Cu-Ni alloys, matching marine corrosion resistance.
- ENi-1: Pure nickel electrodes for commercially pure nickel.
- ENiCu-7: Nickel-copper electrodes for Monel alloys, balancing strength and corrosion resistance.
- ENiCrFe-X: Nickel-chromium-iron electrodes for Inconel and Incoloy alloys, suited for high-temperature applications.
- ENiCrMo-X: Nickel-chromium-molybdenum electrodes for Hastelloy and Inconel 625, offering superior corrosion resistance.
- Selection Considerations:
- Copper Alloys:
- Pure copper (e.g., C11000) requires deoxidized electrodes (ECu) to prevent porosity from oxygen.
- Brasses (e.g., C26000) use ECuSi or ECuSn for better weldability and to minimize zinc fuming.
- Bronzes (e.g., C51000, C95400) need matching tin or aluminum electrodes (ECuSn-A, ECuAl-A2) for strength.
- Copper-nickel alloys (e.g., C70600) use ECuNi to maintain corrosion resistance in seawater.
- Nickel Alloys:
- Monel (e.g., N04400) uses ENiCu-7 for resistance to acids and seawater.
- Inconel (e.g., N06600, N06625) requires ENiCrFe or ENiCrMo electrodes for high-temperature strength and oxidation resistance.
- Hastelloy (e.g., C-276, C-22) uses ENiCrMo electrodes for extreme corrosion resistance in aggressive environments.
- Pure nickel (e.g., N02200) uses ENi-1 for ductility and corrosion resistance in caustic environments.
- Copper Alloys:
- Welding Precautions:
- Copper Alloys:
- Preheat (100–300°C) for thick sections to reduce thermal conductivity issues.
- Use low heat input to avoid burn-through or distortion, especially for thin copper.
- Clean surfaces to remove oxides, which can cause porosity.
- For brasses, ensure ventilation due to zinc fuming.
- Nickel Alloys:
- Low-hydrogen practices are critical to prevent cracking in high-nickel welds.
- Preheat is generally not required, but interpass temperature control (e.g., <150°C) prevents hot cracking.
- Use stringer beads to minimize heat-affected zone (HAZ) issues.
- Clean thoroughly to avoid contamination from sulfur or lead, which can embrittle nickel welds.
- Copper Alloys:
- Dissimilar Welding:
- Copper to steel: Use ECuNi or ENi-1 to handle dilution and thermal expansion differences.
- Nickel to steel: ENiCrFe-3 or ENiCrMo-3 for compatibility and crack resistance.
- Copper to nickel: ECuNi or ENiCu-7 for balanced properties.
- Limitations:
- Copper alloys have high thermal conductivity, requiring higher welding currents or specialized equipment.
- Nickel alloys are prone to hot cracking if not welded with proper filler and technique.
- Some alloys (e.g., beryllium copper) require safety precautions due to toxic fumes.
Nickel and Nickel Alloys
Nickel alloys withstand extreme corrosion and heat, used in aerospace, chemical, and energy sectors. Inconel 718 is a newer high-performance grade.
| Base Metal Grade | SMAW Electrode | GMAW Wire | GTAW Rod | Applications | Notes |
|---|---|---|---|---|---|
| Inconel 600 | ENiCrFe-3 | ERNiCr-3 | ERNiCr-3 | Petrochemical furnaces | Resists oxidation; GTAW for thin sections. |
| Inconel 625 | ENiCrMo-3 | ERNiCrMo-3 | ERNiCrMo-3 | Turbine blades | Broad corrosion resistance; low heat input. |
| Inconel 718 | ENiCrFe-7 | ERNiCrFe-7 | ERNiCrFe-7 | Jet engines | Age-hardenable; PWHT for strength; emerging in aerospace. |
| Monel 400 | ENiCu-7 | ERNiCu-7 | ERNiCu-7 | Marine valves | Copper-nickel alloy; clean to avoid porosity. |
| Hastelloy C-276 | ENiCrMo-4 | ERNiCrMo-4 | ERNiCrMo-4 | Acid reactors | For severe corrosion; use inert shielding gas. |
| Incoloy 800 | ENiCrFe-2 | ERNiCr-3 | ERNiCr-3 | Heat exchangers | High-temperature strength; versatile filler. |
Cast Iron
Cast iron’s brittleness requires specialized fillers, often nickel-based, for repairs in machinery and automotive parts.
| Base Metal Type | SMAW Electrode | GTAW Rod | Applications | Notes |
|---|---|---|---|---|
| Gray Cast Iron | ENi-CI | ERNi-1 | Engine blocks | Pure nickel for machinability; preheat to 150–200°C. |
| Ductile Cast Iron | ENiFe-CI | ERNiFeMn-CI | Gearboxes | Nickel-iron for strength; slow cooling to prevent cracks. |
| Malleable Cast Iron | ENi-CI | ERNi-1 | Pipe fittings | Similar to gray iron; low heat input critical. |
Special Alloys
Special alloys like titanium and cobalt-based materials are used in high-performance applications, with newer grades like 17-4 PH gaining traction.
| Base Metal Grade | GMAW Wire | GTAW Rod | Applications | Notes |
|---|---|---|---|---|
| Titanium Gr. 2 | N/A | ERTi-2 | Medical implants | Inert gas shielding; clean to avoid contamination. |
| Titanium Gr. 5 (Ti-6Al-4V) | N/A | ERTi-5 | Aerospace frames | High strength; argon shielding mandatory. |
| Magnesium AZ31B | N/A | ERMg-1 | Automotive castings | GTAW only; high-purity argon; low heat. |
| Zirconium 702 | N/A | ERZr-2 | Nuclear reactors | Strict cleanliness; specialized shielding. |
| 17-4 PH Stainless | ER630 | ER630 | Turbine shafts | Precipitation-hardening; emerging in high-stress uses; PWHT needed. |
| Stellite 6 | N/A | ERCoCr-A | Hardfacing valves | Cobalt-based; for wear resistance; TIG for precision. |
Dissimilar Metal Welding
Welding different alloys requires fillers that bridge properties, often used in complex assemblies.
| Base Metal Pair | SMAW Electrode | GMAW Wire | GTAW Rod | Applications | Notes |
|---|---|---|---|---|---|
| Carbon Steel to 304 Stainless | E309L-16 | ER309L | ER309L | Industrial piping | Over-alloyed to prevent cracking; clean interfaces. |
| Aluminum to Copper | N/A | ERCuSi-A | ERCuSi-A | Electrical joints | Silicon bronze filler; GTAW with care to avoid melting aluminum. |
| Stainless Steel to Nickel Alloy | ENiCrMo-3 | ERNiCrMo-3 | ERNiCrMo-3 | Chemical plants | Matches higher alloy; control dilution. |
Practical Tips for Filler Metal Selection
- Verify with MTCs: Always check Material Test Certificates to confirm base metal properties before selecting fillers (MTC Guide).
- Clean Thoroughly: Remove oxides, grease, or scale to prevent weld imperfections, especially for aluminum and titanium.
- Match Strength: Ensure filler strength meets or exceeds the base metal’s minimum requirements to avoid weak joints.
- Control Heat Input: High heat can distort thin sections or embrittle alloys like cast iron; use low-current settings where needed.
- Follow Standards: Refer to AWS A5.x or ISO 14343 for precise classifications.
- Test Welds: For critical applications, perform test welds to verify compatibility and inspect for defects.
- Consult Experts: For new alloys or complex jobs, contact manufacturers like Lincoln Electric for tailored advice.
Common Mistakes to Avoid
- Overmatching Strength: Using a filler much stronger than needed (e.g., E9018 for A36 steel) can cause cracking if not properly managed.
- Ignoring Preheat: Skipping preheat for low alloy steels or cast iron risks brittle welds.
- Wrong Shielding Gas: Using CO2 instead of argon for aluminum MIG welding leads to porosity.
- Neglecting Standards: Failing to check AWS or ASME codes can result in non-compliant welds, especially in regulated industries.
Real-World Example: Pipeline vs. Aerospace Welding
Consider two scenarios:
- Pipeline Welding (API 5L X70):
- Choice: E8010-P1 (SMAW) for root, E9045-P2 for fill/cap; ER90S-G (GMAW) for automated welds.
- Reason: Cellulosic electrodes ensure deep penetration for root passes; high-strength fillers match X70’s 70 ksi yield.
- Outcome: Welds pass radiographic testing, ensuring leak-free gas transport.
- Aerospace Welding (Titanium Gr. 5):
- Choice: ERTi-5 (GTAW) with argon shielding.
- Reason: Matches Ti-6Al-4V’s high strength; inert gas prevents contamination.
- Outcome: Welds meet stringent fatigue requirements for aircraft components.
These examples highlight how filler choice adapts to the material and application, balancing strength, process, and environment.
Conclusion
Selecting the right welding electrode or filler metal is a pivotal step in achieving welds that are strong, durable, and fit for purpose. From carbon steel pipelines to titanium aerospace parts, the tables above cover a wide range of alloys, including newer grades like 6013 aluminum and 2507 super duplex, reflecting modern industry needs. By matching fillers to base metals, welding processes, and service conditions, and adhering to standards like AWS and ISO, welders can ensure quality and safety. Whether you’re a seasoned professional or a DIY enthusiast, use these charts as a starting point, verify with material test certificates, and consult experts for complex projects. Your welds are only as good as the choices you make—choose wisely.
Have a welding project in mind? Drop your questions or alloy challenges in the comments, and let’s find the perfect filler solution together!
Key Citations
- AWS Filler Metal Specifications Overview – Comprehensive guide to AWS filler metal classifications.
- Lincoln Electric Welding Solutions – Industry-leading filler metal selection resources.
- ESAB Welding Filler Metal Data – Detailed filler metal recommendations for various alloys.
- Material Welding MTC Guide – Explains material test certificates for base metal verification.
- ISO 14343 Stainless Steel Standard – International standard for stainless steel welding consumables.