AWS A5.18 / ASME SFA-5.18 · Solid MIG wire & TIG rod (GMAW / GTAW)

ER70S-6 MIG Wire and TIG Rod

ER70S-6 is a manganese-silicon deoxidised solid wire classified to AWS A5.18 for gas metal arc welding and gas tungsten arc welding of carbon and carbon-manganese steels, depositing weld metal with a minimum tensile strength of 70,000 psi (490 MPa) and carrying the highest manganese and silicon content of the A5.18 carbon steel wires, which is what lets it weld over mill scale and light rust with low spatter.

Carbon and carbon-manganese steel
Solid MIG wire & TIG rod (GMAW / GTAW)
EN ISO 14341-A
8 ESAB grades

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Price on request. POFIS is an ESAB Authorized Distributor & Service Centre in Abu Dhabi — quotations include confirmed lead time and delivery terms.

The designation

What ER70S-6 means

ER: An electrode or rod — the same filler can be fed as a continuous MIG electrode or cut into lengths as a TIG rod, which is why the prefix carries both letters.
70: Minimum tensile strength of the deposited weld metal in thousands of pounds per square inch — 70,000 psi, which is 490 MPa.
S: Solid wire, as opposed to a tubular flux-cored or metal-cored electrode. All the shielding comes from the gas; the wire itself contributes none.
6: The chemistry suffix, and the part that matters most. A 6 means the highest manganese and silicon of the carbon steel solid wires — roughly 1.4–1.85 % Mn and 0.8–1.15 % Si — which are deoxidisers. They scavenge oxygen from mill scale and surface rust, so the wire tolerates less-than-perfect plate preparation and runs with low spatter.
G3Si1 / G4Si1: The EN ISO 14341-A equivalents. G4Si1 carries more silicon and manganese than G3Si1, giving higher weld metal strength and a more fluid pool. A wire dual-classified ER70S-6 and G4Si1 is the stronger of the two, which is why the EN designation is worth reading even on a page that names the AWS class.

Reading the ER70S-6 designation, left to right.

How it behaves

ER70S-6 in practice

Why ER70S-6 rather than ER70S-3

The difference between the A5.18 grades is deoxidiser content, not strength — both are 70 ksi classes. ER70S-6 carries the most manganese and silicon, so it copes with mill scale, light rust and oily plate that would give an ER70S-3 deposit porosity. On clean, prepared material ER70S-3 welds perfectly well and gives a slightly flatter bead, but in a fabrication shop or on a site weld, the plate is rarely clean enough to make that a sensible gamble. ER70S-6 is the default for a reason.

The shielding gas changes the answer

The same wire gives different mechanical properties under different gas. Pure CO₂ (C1) is cheaper, penetrates deeply and produces more spatter; an argon–CO₂ mix (M21, typically 80/20 or 82/18) gives a smoother arc, far less spatter and higher strength. OK Autrod 12.64 deposits 490 MPa yield under M21 and 460 MPa under CO₂ — a 30 MPa difference from the gas alone. A welding procedure that qualified on M21 is not qualified on CO₂, so match the gas to the WPS and not to what is on the trolley.

Copper-coated or not

Traditional MIG wire carries a thin copper flash that improves electrical contact and resists corrosion in storage. ESAB's AristoRod wires drop the copper in favour of a surface treatment, which cuts copper build-up in the contact tip and the liner. On short runs the difference is academic. On long robotic or mechanised runs — and in a hot, humid workshop where liners clog — it is the difference between a shift of uninterrupted welding and repeated stoppages to change tips.

The same wire in TIG

ER70S-6 is also supplied as cut lengths for TIG welding, where it is shielded by pure argon (I1) rather than a mix. The classification is identical and so is the chemistry, but the properties published against it differ because the gas and the process differ. ESAB lists these separately as the OK Tigrod range; do not order MIG spool wire expecting to use it as TIG filler.

What POFIS supplies

ESAB ER70S-6 grades

Every grade below carries the ER70S-6 classification, which is why a WPS naming ER70S-6 can be satisfied by any of them. They are not interchangeable in practice — the differences in current type, hydrogen level and impact toughness are what decide which one belongs on your job. Figures are the manufacturer's typical as-welded values.

**ER70S-6 grades supplied by POFIS** — typical as-welded properties. Blank cells are values the manufacturer does not publish for that grade, not zeros.
Grade	Classification	Yield	Tensile	Elong.	Impact (lowest published)
OK Autrod 12.51 POFIS recommends	ER70S-6 (AWS A5.18) G 3Si1 / G 42 4 M21 3Si1	460 MPa	560 MPa	26 %	90 J at −40 °C
OK Autrod 12.64	ER70S-6 (AWS A5.18) G 4Si1 / G 46 5 M21 4Si1	490 MPa	590 MPa	29 %	80 J at −50 °C
OK Autrod 12.64 HP	ER70S-6 (AWS A5.18) G 4Si1 / G 50 5 M21 4Si1	540 MPa	630 MPa	26 %	85 J at −60 °C
OK Autrod 12.66	ER70S-6 (AWS A5.18)	545 MPa	600 MPa	26 %	80 J at −30 °C
OK AristoRod 12.50	ER70S-6 (AWS A5.18) G 3Si1 / G 42 4 M21 3Si1	470 MPa	560 MPa	26 %	70 J at −50 °C
OK AristoRod 12.63	ER70S-6 (AWS A5.18) G 4Si1 / G 46 5 M21 4Si1	490 MPa	590 MPa	29 %	80 J at −50 °C
OK Tigrod 12.61	ER70S-6 (AWS A5.18)	470 MPa	560 MPa	26 %	60 J at −40 °C
OK Tigrod 12.64	ER70S-6 (AWS A5.18)	525 MPa	595 MPa	26 %	90 J at −50 °C

OK Autrod 12.51 ER70S-6 (AWS A5.18)

The standard copper-coated general-purpose MIG wire, and the widest diameter range in the group — 0.6 mm for sheet metal through to 1.6 mm. The default for structural and engineering steelwork up to 420 MPa yield.

Diameters: 0.6 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.14 mm, 1.2 mm, 1.32 mm, 1.4 mm, 1.6 mm
Alloy type: Carbon-manganese steel (Mn/Si-alloyed), copper coated
Type: Solid MIG wire (GMAW)
Source: ESAB Filler Metal Handbook, page 1-41

OK Autrod 12.64 ER70S-6 (AWS A5.18)

The higher-silicon G4Si1 version of 12.51: 30 MPa more yield strength from the same classification, a more fluid pool that wets in flatter, and 80 J down at −50 °C.

Diameters: 0.8 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 2.0 mm
Alloy type: Carbon-manganese steel (Mn/Si-alloyed), copper coated
Type: Solid MIG wire (GMAW)
Source: ESAB Filler Metal Handbook, page 1-46

OK Autrod 12.64 HP ER70S-6 (AWS A5.18)

The controlled-purity grade: very low impurity levels and the best low-temperature toughness of the group, holding 85 J at −60 °C. Specify it for sub-zero service and where weld metal cleanliness is under scrutiny.

Alloy type: Carbon-manganese steel (Mn/Si-alloyed), copper coated
Type: Solid MIG wire (GMAW)
Source: ESAB Filler Metal Handbook, page 1-48

OK Autrod 12.66 ER70S-6 (AWS A5.18)

Designed for downhill circumferential GMAW on line pipe in API 5L grades X52 to X70. The grade to quote for pipeline girth welds rather than a general-purpose wire run downhill.

Alloy type: Carbon-manganese steel (Mn/Si-alloyed), copper coated
Type: Solid MIG wire (GMAW), pipeline downhill
Source: ESAB Filler Metal Handbook, page 1-50

OK AristoRod 12.50 ER70S-6 (AWS A5.18)

The non-copper-coated equivalent of 12.51. The surface treatment keeps contact tips and liners clear through long uninterrupted runs, which is why this is the wire for robotic and mechanised welding. Supplied in the octagonal Marathon Pac.

Diameters: 0.8 mm, 0.9 mm, 1.0 mm, 1.14 mm, 1.2 mm, 1.32 mm, 1.4 mm, 1.6 mm, 2.0 mm
Alloy type: Carbon-manganese steel (Mn/Si-alloyed), non copper coated
Type: Solid MIG wire (GMAW)
Approvals: ABS · BV · CE · CWB · DB · DNV-GL · LR · PRS · RINA · UKCA · VdTÜV
Source: ESAB Filler Metal Handbook, page 1-32

OK AristoRod 12.63 ER70S-6 (AWS A5.18)

The non-copper-coated G4Si1: the strength and toughness of 12.64 with AristoRod feedability. The choice where a robotic cell also has to meet a −50 °C impact requirement.

Diameters: 0.8 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm
Alloy type: Carbon-Manganese steel (Mn/Si-alloyed), non copper coated
Type: Solid MIG wire (GMAW)
Source: ESAB Filler Metal Handbook, page 1-37

OK Tigrod 12.61 ER70S-6 (AWS A5.18)

The G3Si1 TIG rod matching OK Autrod 12.51, shielded by pure argon. For root runs and thin-section work on general engineering and structural steels.

Alloy type: Carbon-manganese steel
Type: TIG rod (GTAW), argon I1 shielded
Source: ESAB Filler Metal Handbook, page 1-64

OK Tigrod 12.64 ER70S-6 (AWS A5.18)

The G4Si1 TIG rod, and markedly the tougher of the two: 150 J at −40 °C and 100 J at −46 °C under argon. Specify it where a TIG root stays in a low-temperature service weld.

Alloy type: Carbon-manganese steel
Type: TIG rod (GTAW), argon I1 shielded
Source: ESAB Filler Metal Handbook, page 1-66

Diameters are listed from the manufacturer's deposition data. Ordering part numbers and pack sizes are confirmed with your quotation — send the grade and diameters you need to weldiv@pofis.ae.

Specifying

Which ER70S-6 grade to specify

For general fabrication on a manual MIG set

OK Autrod 12.51 is the standard copper-coated G3Si1/ER70S-6 wire and the usual answer for structural and engineering steelwork up to about 420 MPa yield. It carries the widest diameter range of the group, from 0.6 mm for sheet through to 1.6 mm, so one wire type covers most of a workshop.

When you want more strength from the same classification

OK Autrod 12.64 is the G4Si1 version: more silicon and manganese, 490 MPa typical yield against 460 MPa for 12.51 under the same M21 gas, and a more fluid pool that gives a flatter bead. It holds 80 J at −50 °C. Where a procedure is marginal on strength, moving from 12.51 to 12.64 is often enough without changing classification.

For robotic and mechanised welding

OK AristoRod 12.50 and 12.63 are the non-copper-coated equivalents of 12.51 and 12.64. The surface treatment keeps the contact tip and liner clear over long uninterrupted runs, which is exactly the duty where copper build-up costs production. Both are supplied in the octagonal Marathon Pac bulk drum for continuous feeding.

For low-temperature and high-integrity work

OK Autrod 12.64 HP is the controlled-purity grade: higher strengthening elements, very low impurity levels, and 540 MPa typical yield with 85 J at −60 °C under M21 — the best low-temperature toughness in this group by a clear margin. Specify it where the procedure calls for sub-zero impacts or where weld metal cleanliness is being scrutinised.

For pipeline girth welds

OK Autrod 12.66 is designed for downhill circumferential GMAW on line pipe in API 5L grades X52 to X70, with 545 MPa typical yield under M21. It is the grade to quote for cross-country pipeline and station pipework rather than a general-purpose wire run downhill.

For TIG root runs and thin section

OK Tigrod 12.61 is the G3Si1 rod and OK Tigrod 12.64 the G4Si1, matching 12.51 and 12.64 respectively. 12.64 is markedly tougher — 150 J at −40 °C and 100 J at −46 °C under argon — and is the one to specify where a TIG root will be left in a low-temperature service weld.

Storage & handling

Storing and handling ER70S-6 consumables

Keep wire dry and the drum closed

Solid wire does not absorb moisture the way a basic electrode coating does, but surface rust and condensation on a part-used spool both cause porosity. Store spools in their packaging in a dry area, and close a Marathon Pac between shifts rather than leaving it open to workshop air.

Liners and contact tips are consumables too

Most feeding problems blamed on wire are liner problems. A liner packed with copper flash, drawing lubricant or fine swarf raises feed force until the arc becomes unstable, and the symptom looks like a bad batch of wire. Replace liners on a schedule, match the liner to the wire diameter, and keep the gun as straight as the job allows.

Frequently asked

ER70S-6 — common questions

What does ER70S-6 mean?

ER means an electrode or rod usable for MIG or TIG; 70 is the minimum tensile strength of the weld metal in thousands of psi, so 70,000 psi or 490 MPa; S means a solid wire rather than a tubular one; and 6 is the chemistry suffix, denoting the highest manganese and silicon content of the AWS A5.18 carbon steel wires. Those two elements are deoxidisers, which is what lets ER70S-6 weld over mill scale and light rust with low spatter.

What is the difference between ER70S-6 and ER70S-3?

Strength is the same — both are 70 ksi classes. ER70S-6 carries more manganese and silicon, so it tolerates mill scale, surface rust and residual oil that would leave an ER70S-3 deposit porous. ER70S-3 gives a slightly flatter bead on clean prepared plate and is a little cheaper. In practice most fabrication uses ER70S-6, because plate is rarely as clean as a procedure assumes.

Can ER70S-6 be used with pure CO₂?

Yes, and ESAB publishes properties for CO₂ (C1), M20 and M21. But the figures differ: OK Autrod 12.64 gives 490 MPa yield under M21 and 460 MPa under pure CO₂. CO₂ is cheaper and penetrates more deeply; an argon–CO₂ mix gives a smoother arc with much less spatter and higher strength. Whichever your WPS qualified on is the one you must weld with, because a procedure qualified on a mix is not qualified on CO₂.

What is the difference between AristoRod and Autrod?

Chemistry and classification are the same; the surface is not. Autrod wires are copper-coated in the traditional way. AristoRod wires are non-copper-coated with a surface treatment that stops copper flaking into the contact tip and liner. For short manual runs this makes little difference. For long robotic or mechanised runs it is the difference between a continuous shift and repeated stoppages to clear a liner.

Which ER70S-6 wire diameter should I use?

As a rule: 0.6–0.8 mm for sheet and thin section, 0.9–1.0 mm for general fabrication and positional work, 1.2 mm for most structural welding, and 1.4–2.0 mm for heavy plate and high-deposition mechanised welding. The wire diameter has to suit the machine's output and the feeder rolls as well as the joint, so check the current range for the diameter against your power source.

Is ER70S-6 the same as G3Si1?

They overlap but are not identical. G3Si1 and G4Si1 are the EN ISO 14341-A designations, and both can carry the AWS ER70S-6 classification. G4Si1 has more silicon and manganese than G3Si1 and gives higher weld metal strength. If your procedure is written to EN rather than AWS, read the EN designation — it is the more specific of the two.

Where can I buy ER70S-6 MIG wire in Abu Dhabi?

POFIS supplies the full ESAB OK Autrod, AristoRod and Tigrod ranges from Abu Dhabi across the UAE and the wider GCC. We are an ESAB Authorized Distributor and Service Centre, an approved ADNOC vendor and ISO 9001 certified. Send the diameter, shielding gas and pack type you need to weldiv@pofis.ae for a quotation with confirmed lead time.

Procurement & supply

Buying the ER70S-6 consumables through POFIS

The ER70S-6 consumables is supplied from Abu Dhabi by Perfect Oilfield & Industrial Supply LLC as an ESAB Authorized Distributor and Service Centre. The information below covers what procurement and QA/QC departments normally need before raising a purchase order.

Lead time

Stock items dispatch from Abu Dhabi within 24–48 hours. Indent items are quoted with a confirmed lead time at the time of offer.

Approved vendor status

POFIS is an approved ADNOC vendor and is listed on the approved vendor lists (AVL) of major operators and EPC contractors across the GCC. We can complete supplier registration and prequalification documentation on request.

Payment terms

Standard credit terms are available to registered corporate accounts. LPO, LC and advance payment are all accepted.

Delivery terms

Delivery across the UAE and the wider GCC. Quotations can be issued on EXW, FOB, CIF or DDP terms to suit your project.

Warranty

Full manufacturer warranty, honoured locally. As an ESAB Authorized Service Centre we carry out warranty work and repairs in Abu Dhabi rather than returning equipment abroad.

Service & spares

In-UAE service, commissioning, operator training and spare parts backing for every machine we supply.

ISO 9001 Certified
Approved ADNOC Vendor
ESAB Authorized Distributor & Service Centre

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