What is the scope of AWS A5.29 / A5.29M?
AWS A5.29/A5.29M is the American Welding Society specification that prescribes requirements for the classification of low-alloy steel electrodes used in flux cored arc welding (FCAW), with or without external shielding gas.[reference:0] The standard covers tubular (flux cored) electrodes, including both gas-shielded and self-shielded types.[reference:1] Classification is based on the chemical composition and mechanical properties of the weld metal, along with certain usability characteristics.[reference:2] Optional supplemental designators are provided for improved toughness, diffusible hydrogen limits, and shielding gas ranges.[reference:3] The specification addresses standard sizes, marking, manufacturing, and packaging requirements.[reference:4] A guide is appended to the standard as a source of information concerning the classification system and the intended use of low-alloy steel flux cored electrodes.[reference:5] The current edition is AWS A5.29/A5.29M:2022, the sixth edition, which revises the 2021 edition.[reference:6] The specification uses both U.S. Customary Units and SI units, and each system must be used independently of the other.[reference:7] Metal cored low-alloy steel electrodes are not classified under this specification; they are classified under AWS A5.28/A5.28M.[reference:8]
What is the classification system used in AWS A5.29 / A5.29M?
The AWS A5.29 classification system follows the format EXXTX-X#M, where each element carries specific technical meaning.[reference:9] The prefix “E” denotes an electrode.[reference:10] The following two digits indicate the minimum tensile strength of the weld metal in units of 10 ksi (or 10 MPa for A5.29M): 6 = 60 ksi (420 MPa), 7 = 70 ksi (480 MPa), 8 = 80 ksi (550 MPa), 9 = 90 ksi (620 MPa), 10 = 100 ksi (690 MPa), 11 = 110 ksi (760 MPa), and 12 = 120 ksi (830 MPa).[reference:11] The next digit designates the welding position: 0 = flat and horizontal only, and 1 = all positions.[reference:12] The letter “T” indicates a tubular electrode.[reference:13] The numeral following “T” identifies the type of electrode: 1 and 5 are gas-shielded types, while 4 and 8 are self-shielded types.[reference:14] The chemical composition designator follows the hyphen: A = carbon-molybdenum steel, B = chromium-molybdenum steel, C = nickel steel, D = manganese-molybdenum steel, K = other alloy steels, W = weathering steel, and G = general classification.[reference:15] The suffix “M” indicates that the electrode was classified using 75–80% Ar with balance CO₂.[reference:16] Optional supplemental designators include J for improved toughness and HZ for diffusible hydrogen limits, where Z specifies the maximum hydrogen content in ml/100g.[reference:17] Verify the complete designator rules with the latest edition.
What is the complete list of AWS A5.29 / A5.29M classifications?
The classifications below are compiled from multiple public sources, including manufacturer data sheets, technical reference tables, and standard summaries.
Because AWS standards are periodically revised, verify the complete and current list with the latest edition.
Carbon-molybdenum steel classifications (A designator)
E70T4-A1
E70T5-A1
E71T1-A1
E80T1-A1
E81T1-A1
E81T1-A1C
These classifications designate carbon-molybdenum steel electrodes containing approximately 0.5% molybdenum.[reference:18][reference:19][reference:20] E70T5-A1 is a gas-shielded electrode requiring CO₂ shielding, while E70T4-A1 is a self-shielded electrode.[reference:21] The “1” position designator indicates all-position welding capability for the E71T1 and E81T1 series.[reference:22] Verify the complete A-series list with the latest edition.
Chromium-molybdenum steel classifications (B designator)
E80T1-B1
E81T1-B1
E80T1-B2
E80T1-B2H
E81T1-B2
E81T1-B2C according to EN ISO 17634-A-T CrMo1 P C
E80T5-B2
E80T5-B2L
E90T1-B3
E91T1-B3
E91T1-B3C
E91T1-B3M
E90T5-B3M
E91T1-B6C
E91T1-B6M
E91T1-B9M
These classifications designate chromium-molybdenum steel electrodes with varying chromium and molybdenum contents.[reference:23][reference:24][reference:25] B1 contains approximately 0.5% Cr-0.5% Mo, B2 contains approximately 1.25% Cr-0.5% Mo, B3 contains approximately 2.25% Cr-1% Mo, B6 contains approximately 5% Cr-0.5% Mo, and B9 contains approximately 9% Cr-1% Mo.[reference:26] The “L” suffix designates low-carbon versions, while the “H” suffix indicates high-carbon versions.[reference:27] The “C” and “M” suffixes designate CO₂ and Ar-CO₂ mixed gas shielding, respectively. Verify the complete B-series list with the latest edition.
Nickel steel classifications (C and Ni designators)
E71T8-Ni1
E71T8-Ni2
E80T1-Ni1
E81T1-Ni1
E81T1-Ni1C
E81T1-Ni1M
E80T1-Ni2
E81T1-Ni2
E81T1-Ni2C
E81T1-Ni2M
E80T5-Ni1
E80T5-Ni2
E80T5-Ni3
These classifications designate nickel steel electrodes with nickel contents ranging from approximately 1% to 3.5%.[reference:28][reference:29][reference:30] The E71T8-Ni1 and E71T8-Ni2 classifications are self-shielded electrodes that require no external shielding gas.[reference:31] The E81T1-Ni1C and E81T1-Ni1M classifications are gas-shielded electrodes designed for low-temperature toughness applications.[reference:32] E80T5-Ni3 offers the highest nickel content and correspondingly the best low-temperature impact toughness among the nickel steel classifications.[reference:33] Verify the complete nickel steel list with the latest edition.
Manganese-molybdenum steel classifications (D designator)
E90T5-D2
E91T5-D2
These classifications designate manganese-molybdenum steel electrodes containing approximately 1.75% manganese and 0.5% molybdenum.[reference:34] The D2 designation corresponds to the same alloy system found in solid wire classifications under AWS A5.28, such as ER80S-D2. Verify the complete D-series list with the latest edition.
Other alloy steel classifications (K designator)
E61T8-K6
E70T4-K2
E71T8-K2
E71T8-K6
E80T1-K2
E80T5-K1
E80T5-K2
E81T1-K2
E81T1-K2C
E81T1-K2M
E90T5-K2
E90C-K3
E91T1-K3
E91T1-K3C
E91T1-K3M
E100T5-K3
E100T5-K4
E101T1-K3
E110T5-K3
E110T5-K4
E111T1-K3
E110T5-KAM
These classifications designate other low-alloy steel electrodes with proprietary or specialized alloy compositions optimized for specific strength and toughness requirements.[reference:35][reference:36][reference:37] The K2 designations typically contain approximately 1.5% nickel along with titanium and boron additions for enhanced toughness.[reference:38] The K3 and K4 designations provide higher strength levels for demanding structural applications. E110T5-K3 and E110T5-K4 offer minimum tensile strengths of 110 ksi (760 MPa).[reference:39] The KAM designation is a variation within the K-series. Verify the complete K-series list with the latest edition.
Weathering steel classifications (W designator)
E80T1-W
E81T1-W2C
These classifications designate weathering steel electrodes formulated to provide corrosion resistance and color-match properties equivalent to weathering steels such as ASTM A588 and A242.[reference:40][reference:41] The W2C suffix indicates a specific weathering steel composition with CO₂ shielding. Verify the complete W-series list with the latest edition.
General and unclassified electrodes (G designator)
E70T4-G
E71T1-GC
E71T1-GM
E80T1-GC
E80T5-GM
E81T1-GC
E81T1-GM
E91T1-GC
E100T5-G
E101T1-G
E110T1-G
E110T1-K3C
E111T1-G
E111T1-GM
E120T1-G
E121T1-G
E110C-G
The “G” designator indicates a general classification for which the chemical composition of the deposited weld metal is not specified by the standard and is instead established by agreement between supplier and purchaser.[reference:42] These classifications may be either modifications of other discrete classifications or entirely new classifications.[reference:43] The “C” and “M” suffixes indicate CO₂ and mixed gas shielding conditions, respectively. Verify the complete G-series list with the latest edition.
What are the mechanical property requirements for AWS A5.29 electrodes?
The mechanical property requirements for AWS A5.29 filler metals include minimum tensile strength, minimum yield strength, minimum elongation, and Charpy V-notch impact toughness.
For E81T1-Ni1, typical values include a yield strength of 470–500 MPa (68–72 ksi), a tensile strength of 550–690 MPa (80–100 ksi), and a minimum elongation of 19%.[reference:44] Impact toughness for E81T1-Ni2 reaches 47 J minimum at –60°C, making it suitable for offshore and low-temperature applications.[reference:45] For E110T5-K3 and E110T5-K4, the minimum tensile strength is 760 MPa (110 ksi), with yield strengths of 680–690 MPa and minimum elongations of 16–17%.[reference:46] The impact test temperature designator (0, 2, 4, 5, 6, or 8) indicates the temperature at which the weld metal meets or exceeds 27 J (20 ft·lbf).[reference:47] E81T1-Ni1JH4, for example, indicates improved toughness (J) and a diffusible hydrogen limit of 4 ml/100g (H4).[reference:48] The precise mechanical property tables are contained within the standard and should be consulted directly for design and qualification purposes.
Verify all mechanical property requirements with the latest edition.
AWS A5.29/A5.29M does not exist in isolation; several companion specifications provide complementary or overlapping coverage for low-alloy steel filler metals.[reference:49] AWS A5.28/A5.28M specifies low-alloy steel electrodes and rods for gas shielded arc welding, covering solid wires and metal cored electrodes, whereas A5.29 addresses flux cored wires.[reference:50] AWS A5.20/A5.20M addresses carbon steel electrodes for flux cored arc welding, serving as the carbon steel counterpart to A5.29.[reference:51] AWS A5.23/A5.23M specifies low-alloy steel electrodes and fluxes for submerged arc welding.
AWS A5.36/A5.36M provides a unified classification system for carbon and low-alloy steel flux cored and metal cored electrodes, incorporating classifications from multiple filler metal specifications.[reference:52] The ASME Boiler and Pressure Vessel Code, Section II, Part C, adopts AWS A5.29 as SFA-5.29, and users should confirm the corresponding SFA edition for their application.
Consulting these specifications together provides a comprehensive framework for filler metal selection, qualification, and quality assurance.
The AWS filler metal classification system is organized by welding process and base metal type, with each specification (A5.x) addressing a distinct process or product form.
AWS A5.29 is part of this hierarchical system and addresses low-alloy steel flux cored electrodes specifically.
The “A5” series covers filler metals for arc welding, and the numbering sequence roughly corresponds to the chronological development of the specifications.
The “/A5.29M” suffix indicates that the specification includes both U.S. Customary Units and SI units, a convention applied to AWS standards that have been harmonized with ISO practices.[reference:53] The 2022 edition introduced several important updates, including new optional supplemental designators for shielding gas ranges and diffusible hydrogen limits.
Users should always confirm that they are working from the most current edition of any AWS specification, as classifications and requirements may be added, revised, or withdrawn between editions.
Verify the current edition number and any superseded designations with the latest edition of AWS A5.29/A5.29M.
