E7018 means a covered stick Electrode (E) with 70 ksi minimum tensile strength (70), usable in all positions (1), with a low-hydrogen potassium iron-powder covering that runs on AC or DCEP (8). Every AWS filler classification follows a pattern like this, and the ISO systems carry the same information in a different order.
This chart decodes the AWS classifications you will see on rod, wire and tungsten packets: A5.1 and A5.5 stick electrodes, A5.18 MIG and TIG wire, A5.20 flux-cored wire, A5.9 stainless, A5.10 aluminium and A5.12 tungsten, with the nearest ISO 2560, ISO 14341 and related designations. Read the tables for each digit and letter, then use the searchable list of common fillers at the end to see what each is used for. To choose a filler for a particular base metal, see the filler metal selection chart.
Stick electrodes: AWS A5.1 (E7018, E6010, E6013)
| Part | Meaning |
|---|---|
| E | Electrode (covered, for SMAW / stick welding) |
| 70 | Minimum tensile strength of the weld metal: 70 ksi (480 MPa). E60xx = 60 ksi (430 MPa). |
| 1 | Positions: 1 = all positions |
| 8 | With the 3rd digit, the covering and current: 18 = low hydrogen, potassium, iron powder, AC or DCEP |
Position digit (third from the end)
| Digit | Positions | Examples |
|---|---|---|
| 1 | All positions: flat, horizontal, vertical (up), overhead | E6010, E6011, E6013, E7018 |
| 2 | Flat and horizontal fillet only | E7024, E7028, E6027 |
| 4 | Flat, horizontal, overhead and vertical down | E7048 |
Last two digits: covering and current
| Last two digits | Covering | Current | Typical electrode and use |
|---|---|---|---|
| EXX10 | High cellulose, sodium | DCEP | E6010: deep digging arc, pipe roots, dirty steel |
| EXX11 | High cellulose, potassium | AC or DCEP | E6011: like 6010 but runs on AC |
| EXX12 | High titania, sodium | AC or DCEN | E6012: fill passes, poor fit-up, shallow penetration |
| EXX13 | High titania, potassium | AC, DCEP or DCEN | E6013: easy arc, thin sheet, general light work |
| EXX14 | Iron powder, titania | AC, DCEP or DCEN | E7014: faster than 6013, smooth bead |
| EXX15 | Low hydrogen, sodium | DCEP | E7015: low hydrogen on DC |
| EXX16 | Low hydrogen, potassium | AC or DCEP | E7016: low hydrogen, runs on AC |
| EXX18 | Low hydrogen, potassium, iron powder | AC or DCEP | E7018: structural, code work, crack-sensitive steels |
| EXX19 | Iron oxide, titania, potassium | AC, DCEP or DCEN | E6019: general purpose |
| EXX20 | High iron oxide | AC or DCEN (H-fillet); AC, DCEP or DCEN (flat) | E6020: flat and horizontal fillets |
| EXX22 | High iron oxide | AC or DCEN | E6022: single-pass, high speed |
| EXX24 | Iron powder, titania | AC, DCEP or DCEN | E7024: very high deposition flat and horizontal fillets |
| EXX27 | High iron oxide, iron powder | AC or DCEN (H-fillet); AC, DCEP or DCEN (flat) | E7027: high deposition, deep groove welds |
| EXX28 | Low hydrogen, potassium, iron powder | AC or DCEP | E7028: low hydrogen, high deposition flat and horizontal |
| EXX48 | Low hydrogen, potassium, iron powder | AC or DCEP | E7048: low hydrogen with vertical-down capability |
DCEP = direct current electrode positive (reverse polarity). DCEN = electrode negative (straight polarity). Low-hydrogen types (15, 16, 18, 28, 48) must be kept dry: store opened rods in a holding oven, typically 120 °C (250 °F) or as the maker states.
Optional designators after the classification
| Designator | Meaning | Used in |
|---|---|---|
| -1 | Improved toughness (for example E7018-1: Charpy 27 J at −46 °C / 20 ft·lbf at −50 °F) and, for E7024-1, improved ductility | A5.1 |
| M | Military-type requirements: stricter moisture, toughness and hydrogen limits (E7018M, E11018M) | A5.1, A5.5 |
| H4, H8, H16 | Maximum diffusible hydrogen: 4, 8 or 16 mL per 100 g of weld metal | A5.1, A5.5, A5.20 |
| R | Moisture-resistant covering: passes the absorbed moisture test after exposure to humid air | A5.1, A5.5 |
Low-alloy stick electrodes: AWS A5.5 suffixes (E8018-B2, -C1, -G)
A5.5 electrodes read the same way as A5.1 (E8018 = 80 ksi, all positions, low-hydrogen iron powder), then add a suffix for the alloy. E8018-B2 is an 80 ksi low-hydrogen electrode with 1.25% chromium and 0.5% molybdenum. H4, H8 and R work as in A5.1, for example E8018-C3 H4R.
| Suffix | Alloy | Typical use |
|---|---|---|
| -A1 | Carbon–molybdenum (0.5 Mo) | E7018-A1: C-Mo boiler plate and pipe |
| -B1 | 0.5 Cr – 0.5 Mo | E8018-B1 |
| -B2 | 1.25 Cr – 0.5 Mo | E8018-B2: P11 / F11 pipe and fittings |
| -B2L | As B2, low carbon (0.05% max) | E8018-B2L: better toughness, used where PWHT is limited (check the WPS) |
| -B3 | 2.25 Cr – 1 Mo | E9018-B3: P22 / F22 |
| -C1 | 2.5 Ni | E8018-C1: low-temperature service |
| -C2 | 3.5 Ni | E8018-C2: lower-temperature service |
| -C3 | 1 Ni (with limits on Cr, Mo, V) | E8018-C3: higher-strength structural steels, toughness |
| -D1, D2, D3 | Manganese–molybdenum | E9018-D1: higher-strength Mn-Mo steels |
| -NM1 | Nickel–molybdenum | E8018-NM1 |
| -W1, W2 | Weathering steel (Cu, Cr, Ni) | E8018-W2: weathering steels such as A588 |
| -P1, P2 | Pipeline (cellulosic) | E8010-P1: API 5L pipe, vertical down |
| -G | General: chemistry agreed between supplier and buyer, only a minimum of one alloying element required | E8018-G, E9018-G |
| M | Military high-strength | E11018M: HY-80 and quenched-and-tempered steels |
MIG and TIG wire: AWS A5.18 (ER70S-6, ER70S-3)
| Part | Meaning |
|---|---|
| ER | Electrode or Rod: usable as a MIG electrode or a TIG filler rod |
| 70 | 70 ksi (480 MPa) minimum tensile strength |
| S | Solid wire (C = composite / metal-cored) |
| 6 | Chemistry number: deoxidiser content (Mn, Si, and Al-Ti-Zr for S-2) |
| Classification | Chemistry | Use it for |
|---|---|---|
| ER70S-2 | Triple deoxidised (Al, Ti, Zr) | Rusty or dirty steel, TIG and MIG root passes, best for X-ray quality on less-clean steel |
| ER70S-3 | Moderate Mn and Si | Clean steel, general MIG and TIG, good with argon mixes |
| ER70S-4 | More Si than S-3 | Slightly better wetting than S-3 on lightly scaled steel |
| ER70S-6 | Highest Mn and Si | The everyday MIG wire: mill scale, light rust, CO2 or Ar/CO2, smooth wetting |
| ER70S-7 | Higher Mn, lower Si | Fewer silicon islands on the bead, slightly higher strength than S-6 |
| E70C-6M | Metal-cored (C = composite), M gas | High deposition, little slag, flat and horizontal production welding |
Low-alloy solid wires are in AWS A5.28 and read the same way, with a suffix like A5.5: ER80S-D2 (Mo), ER80S-Ni1, ER80S-B2, ER90S-B3. For MIG settings see the MIG wire feed speed and amperage calculator.
Flux-cored wire: AWS A5.20 (E71T-1C, E71T-11)
| Part | Meaning |
|---|---|
| E | Electrode |
| 7 | Minimum tensile strength × 10 ksi: 70 ksi (480 MPa) |
| 1 | Positions: 0 = flat and horizontal only, 1 = all positions |
| T | Tubular (flux-cored) electrode |
| -1 | Usability: shielding, polarity and slag type (table below) |
| C | Shielding gas: C = 100% CO2, M = 75–80% argon / balance CO2; no letter = self-shielded |
| T-number | Shielding | Polarity | Characteristics |
|---|---|---|---|
| T-1 | Gas (C or M) | DCEP | Rutile slag, spray-like arc, single and multi-pass. E71T-1C/M is the common all-position gas-shielded flux-core. |
| T-2 | Gas | DCEP | Like T-1 but higher Mn/Si: single pass only, can weld over more scale. |
| T-3 | Self-shielded | DCEP | Single pass, high speed on thin sheet. |
| T-4 | Self-shielded | DCEP | High deposition, shallow penetration, crack resistant, flat and horizontal. |
| T-5 | Gas | DCEP (some DCEN) | Basic (lime-fluoride) slag: better toughness and crack resistance than T-1, mainly flat and horizontal. |
| T-6 | Self-shielded | DCEP | Deep penetration, good toughness, easy slag removal in deep grooves. |
| T-7 | Self-shielded | DCEN | High deposition, multi-pass, flat and horizontal (some all-position). |
| T-8 | Self-shielded | DCEN | Good low-temperature toughness, all positions; structural and seismic work. |
| T-9 | Gas | DCEP | Like T-1 with improved impact toughness. |
| T-10 | Self-shielded | DCEN | Single pass, high speed, any thickness, flat and horizontal. |
| T-11 | Self-shielded | DCEN | General purpose, all positions, single and multi-pass; the maker limits the plate thickness. |
| T-12 | Gas | DCEP | Like T-1 with lower Mn to meet hardness limits and improved toughness. |
| T-13 | Self-shielded | DCEN | Root passes on pipe and other single-pass, short-circuit work. |
| T-14 | Self-shielded | DCEN | Single pass, very high speed on thin, coated or galvanised sheet. |
| T-G, T-GS | Not specified | Not specified | Usability not covered by another class (GS = single pass). |
Optional J = Charpy 27 J (20 ft·lbf) at −40 °C / −40 °F; D = tested to the seismic (AWS D1.8) heat-input requirements; H4/H8/H16 as above. Newer AWS A5.36 uses an open classification (for example E71T1-C1A0-CS1-H8) that names the gas and test condition directly; many packets now show both.
Stainless steel filler: AWS A5.9 and A5.4 (ER308L, ER309L, ER316L)
The number is the alloy type, usually matching the base metal series (308 filler for 304 base, because the filler carries a little more alloy and ferrite to resist hot cracking). L = 0.03% carbon max, which resists sensitisation and intergranular corrosion. Si = higher silicon for better wetting in MIG. H = higher carbon for high-temperature strength. Covered electrodes (A5.4) end in -15, -16 or -17 for the covering type.
| Classification | Nominal alloy | Use it for |
|---|---|---|
| ER308L | 19 Cr – 10 Ni, 0.03% C max | 304 and 304L stainless |
| ER308LSi | As 308L with more silicon (0.65–1.0%) | MIG on 304: wetter puddle, flatter bead |
| ER309L | 23 Cr – 12 Ni, low carbon | Stainless to carbon steel, 309 base metal, first layer of overlays |
| ER309LMo | 309L with 2–3% Mo | Dissimilar joints to 316, overlays on carbon steel |
| ER316L | 19 Cr – 12 Ni – 2.5 Mo, low carbon | 316 and 316L stainless |
| ER347 | 19 Cr – 10 Ni stabilised with niobium | 321 and 347, high-temperature service |
| ER310 | 26 Cr – 21 Ni | 310 heat-resistant stainless |
| ER312 | 29 Cr – 9 Ni, high ferrite | Hard-to-weld and dissimilar steels, tool steel repairs |
| ER2209 | 22 Cr – 9 Ni – 3 Mo duplex (over-alloyed in Ni) | 2205 duplex stainless |
| E308L-16 | Covered electrode (A5.4), rutile covering | Stick welding 304: -15 = DCEP basic, -16 = AC or DCEP, -17 = AC or DCEP, smoother rutile-silica |
Aluminium filler: AWS A5.10 (ER4043, ER5356)
Aluminium fillers use the Aluminum Association alloy number. 4xxx fillers are silicon alloys (fluid, crack resistant); 5xxx fillers are magnesium alloys (stronger, better colour match after anodising). ER = usable as MIG wire or TIG rod; R alone = rod only.
| Classification | Nominal alloy | Use it for |
|---|---|---|
| ER1100 | 99% Al | 1xxx and 3003; high conductivity and corrosion resistance |
| ER4043 | Al – 5 Si | 6061, 6082, 3003 and castings; fluid, crack resistant, bright bead; turns grey when anodised |
| ER4047 | Al – 12 Si | Low melting point, castings and joints prone to cracking, also used for brazing |
| ER4943 | Al – 5.5 Si – 0.4 Mg | Like 4043 with higher as-welded strength |
| ER5356 | Al – 5 Mg | 5xxx and 6xxx; stronger and more ductile than 4043, better anodised colour match |
| ER5183 | Al – 4.8 Mg – 0.7 Mn | 5083 and 5086 marine plate; highest strength of the common fillers |
| ER5556 | Al – 5.1 Mg – 0.8 Mn | High-strength 5xxx, similar to 5183 |
| ER5554 | Al – 2.7 Mg – 0.8 Mn | 5454 and service above about 65 °C (150 °F) |
Tungsten electrodes: AWS A5.12 colour codes
| AWS class | Oxide | AWS colour | ISO 6848 class and colour | Typical use |
|---|---|---|---|---|
| EWP | Pure tungsten | Green | WP: green | AC aluminium on older transformer machines (balled tip) |
| EWCe-2 | 2% ceria | Orange | WC20: grey | Low-amp DC, easy starts, thin sheet |
| EWLa-1 | 1% lanthana | Black | WL10: black | AC or DC |
| EWLa-1.5 | 1.5% lanthana | Gold | WL15: gold | AC or DC, close to thoriated performance |
| EWLa-2 | 2% lanthana | Blue | WL20: blue | AC or DC all-rounder; a good default |
| EWTh-1 | 1% thoria | Yellow | WT10: yellow | DC steel and stainless (radioactive grinding dust) |
| EWTh-2 | 2% thoria | Red | WT20: red | DC steel and stainless (radioactive grinding dust) |
| EWZr-1 | Zirconia | Brown | WZ8: white (WZ3: brown) | AC aluminium, holds a balled tip |
| EWG | Other or blended oxides | Maker's colour | Not listed | Rare-earth blends such as E3 (purple) |
AWS and ISO use the same colours except 2% ceriated (orange in AWS, grey in ISO) and zirconiated. For size and grind angle see the TIG tungsten selector.
ISO equivalents: ISO 2560 and ISO 14341
ISO 2560-A, used in Europe, classifies by yield strength and impact temperature instead of tensile strength. A typical E7018 is classified E 42 4 B 42 H5:
| Part | Meaning |
|---|---|
| E | Covered electrode |
| 42 | Minimum yield strength 420 MPa (35 = 355, 38 = 380, 46 = 460, 50 = 500 MPa) |
| 4 | Charpy 47 J at −40 °C (Z = none, A = +20, 0 = 0, 2 = −20, 3 = −30, 4 = −40, 5 = −50, 6 = −60 °C) |
| B | Covering: B = basic (low hydrogen). Others: R rutile, RB rutile-basic, RC rutile-cellulosic, RR thick rutile, C cellulosic, A acid |
| 4 | Weld metal recovery and current: 4 = over 105 up to 125%, DC only (odd numbers 1, 3, 5, 7 = AC and DC) |
| 2 | Positions: 1 all; 2 all except vertical down; 3 flat butt, flat and horizontal fillet; 4 flat; 5 vertical down plus 3 |
| H5 | Diffusible hydrogen 5 mL per 100 g max (H10, H15 also used) |
ISO 14341-A reads the same way for MIG wire: G 42 4 M21 3Si1 = gas-shielded (G), 420 MPa yield, 47 J at −40 °C, gas M21 (argon + 15–25% CO2; C1 = 100% CO2), wire chemistry 3Si1. The "B" versions of the ISO standards (ISO 2560-B, ISO 14341-B) follow the AWS pattern with metric tensile strength: E4918 is the E7018 equivalent.
| AWS | Nearest ISO designation | Standard | Notes |
|---|---|---|---|
| E7018 | E 42 4 B 42 H5 (typical; check the maker) | ISO 2560-A | ISO 2560-B: E4918 |
| E6013 | E 38 0 RC 11 or E 38 2 RB 12 (depends on product) | ISO 2560-A | ISO 2560-B: E4313 |
| E6010 | E 38 3 C 21 (typical) | ISO 2560-A | ISO 2560-B: E4310 |
| ER70S-6 | G 42 4 M21 3Si1 (or G4Si1) | ISO 14341-A | ISO 14341-B wire symbol: S6 |
| E71T-1M | T 42 2 P M21 1 H10 (typical) | ISO 17632-A | P = rutile, fast-freezing slag |
| ER308L | G 19 9 L | ISO 14343-A | ER316L = G 19 12 3 L; ER309L = G 23 12 L |
| ER4043 | S Al 4043A (AlSi5) | ISO 18273 | ER5356 = S Al 5356 (AlMg5Cr(A)) |
| EWLa-2 | WL20 | ISO 6848 | Same blue band |
Equivalents are approximate. The full ISO designation depends on the tested properties of each product, so one AWS class can map to several ISO designations. Check the maker's data sheet, which normally lists both.
Common electrodes and wires and what they are for
| Classification | Standard and process | Current | Typical use |
|---|---|---|---|
| E6010 | A5.1 SMAW | DCEP | Pipe roots, deep penetration, dirty or painted steel, vertical down roots |
| E6011 | A5.1 SMAW | AC, DCEP | Farm and repair work on AC machines, rusty steel |
| E6013 | A5.1 SMAW | AC, DC± | Light sheet, general repair, easy to strike, smooth bead |
| E7014 | A5.1 SMAW | AC, DC± | General fabrication, faster than 6013 |
| E7018 | A5.1 SMAW | AC, DCEP | Structural steel, code and crack-sensitive work; keep rods in a holding oven |
| E7018-1 H4R | A5.1 SMAW | AC, DCEP | As 7018 with −46 °C toughness, very low hydrogen, moisture resistant |
| E7024 | A5.1 SMAW | AC, DC± | Long flat and horizontal fillets, high deposition |
| E8018-B2 | A5.5 SMAW | AC, DCEP | 1.25Cr-0.5Mo pipe (P11), with preheat and PWHT |
| E8018-C3 | A5.5 SMAW | AC, DCEP | Higher-strength steels needing toughness |
| E11018M | A5.5 SMAW | DCEP | High-strength quenched and tempered steels (T-1 / A514, HY-80) |
| ER70S-3 | A5.18 GMAW / GTAW | DCEP (MIG) | Clean mild steel, general MIG and TIG |
| ER70S-6 | A5.18 GMAW / GTAW | DCEP (MIG) | All-purpose MIG wire for mild steel with scale or light rust |
| ER70S-2 | A5.18 GTAW / GMAW | DCEN (TIG) | TIG rod for mild steel, root passes |
| ER80S-D2 | A5.28 GMAW / GTAW | DCEP (MIG) | Mo-bearing wire for 4130-type and higher-strength steels |
| E71T-1C / E71T-1M | A5.20 FCAW-G | DCEP | All-position gas-shielded flux-core, structural fabrication |
| E71T-11 | A5.20 FCAW-S | DCEN | Gasless flux-core for light outdoor and general work (thickness limited) |
| E71T-8 | A5.20 FCAW-S | DCEN | Gasless structural and seismic work needing toughness |
| E70T-4 | A5.20 FCAW-S | DCEP | High-deposition gasless flat and horizontal welds |
| ER308L | A5.9 GMAW / GTAW | DCEP / DCEN | 304 and 304L stainless |
| ER309L | A5.9 GMAW / GTAW | DCEP / DCEN | Stainless to carbon steel |
| ER316L | A5.9 GMAW / GTAW | DCEP / DCEN | 316 and 316L stainless |
| E308L-16 | A5.4 SMAW | AC, DCEP | Stick welding 304 stainless |
| ER4043 | A5.10 GMAW / GTAW | DCEP / AC | 6061, 6082, castings: crack resistant |
| ER5356 | A5.10 GMAW / GTAW | DCEP / AC | 5xxx and 6xxx, higher strength, anodising |
| ER5183 | A5.10 GMAW / GTAW | DCEP / AC | 5083 marine plate |
No rows match that search.
Shop tips
- Hydrogen is the cause of most cracking in hard or thick steel. Use low-hydrogen fillers (E7018, H4/H8 wires), keep them dry and preheat as needed; the weld preheat calculator gives a starting temperature.
- Strength matters less than you think for mild steel: E70 filler already over-matches common structural steels. Toughness, hydrogen level and position usually decide the choice.
- When a WPS names a classification, use that classification or an approved alternative; a "similar" filler is not automatically allowed.
- Check the polarity on the packet. Self-shielded flux-core like E71T-11 runs DCEN, the opposite of solid MIG wire.
Related calculators and charts
Sources: AWS A5.1, A5.4, A5.5, A5.9, A5.10, A5.12, A5.18, A5.20 and A5.28 filler metal specifications; ISO 2560, ISO 14341, ISO 14343, ISO 17632, ISO 18273 and ISO 6848. Descriptions are summaries; ISO equivalents are approximate. Check the current edition of the specification and the maker's data sheet for critical work.