AWS A5.4 / ASME SFA-5.4 · Stainless stick electrode (SMAW / MMA)

E309L Dissimilar Metal Electrodes

E309L is an over-alloyed, extra-low-carbon austenitic stainless steel covered electrode classified to AWS A5.4 for welding stainless steel to carbon and low-alloy steel, for buffer and buttering layers before stainless cladding, and for welding 24 % chromium, 13 % nickel materials, carrying deliberately high chromium and nickel so the deposit remains austenitic and crack-free after it is diluted by the carbon steel side of the joint.

Dissimilar joints, stainless to carbon steel, and 309 / 24Cr-13Ni
Stainless stick electrode (SMAW / MMA)
EN ISO 3581-A
3 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 E309L means

E: A covered electrode for shielded metal arc welding (stick or MMA).
309: The weld metal composition, nominally 22–25 % chromium and 12–14 % nickel. It is substantially richer in both than the 304 or 316 material it is usually welding, and that excess is the entire point.
L: Extra low carbon, limiting chromium carbide precipitation and the intergranular corrosion that follows it. Important here because a dissimilar joint already has enough metallurgical complication without adding sensitisation.
Mo (E309LMo): A separate classification with roughly 2 to 3 % molybdenum added. Specify it when the stainless side of the joint is 316 or 316L, so the deposit carries the pitting resistance that side of the joint was chosen for. Plain E309L has no molybdenum.
-15 / -17: The coating. -15 is basic and DC+ only, with tougher weld metal and better low-temperature impacts. -17 is a silica-bearing rutile coating usable on AC and DC, with a fluid slag and a flatter bead — easier to run, particularly for cladding and surfacing passes.

Reading the E309L designation, left to right.

How it behaves

E309L in practice

Dilution is the problem E309L solves

When stainless is welded to carbon steel, the molten pool contains metal from both sides. A 308L or 316L deposit diluted by perhaps 30 % plain carbon steel ends up well short of the chromium and nickel it needs to stay austenitic, and the joint can solidify partly martensitic — hard, brittle, and liable to crack either immediately or under service load. E309L starts from a much richer composition, so that after the same dilution the deposit is still comfortably austenitic. It is not a better stainless electrode; it is an electrode formulated to survive being watered down.

Buttering and cladding

The same property makes E309L the standard first layer when carbon steel is to be clad with stainless, or when a stainless component will be welded to a carbon steel one later. A buttering layer of 309L is deposited on the carbon steel and, once it is thick enough that further passes no longer reach the parent, the remaining layers are made with the final stainless grade — 308L or 316L as the service requires. The 309L layer absorbs the dilution so the working surface does not have to.

Match the molybdenum to the stainless side

If the stainless side of a dissimilar joint is 316 or 316L, plain E309L leaves the joint with no molybdenum and therefore no pitting resistance where the 316L was specified to provide it. E309LMo exists for that case. The rule is simple: the deposit should carry whatever the stainless side was chosen for, after allowing for dilution — and that usually means over-alloying on that axis too.

Carbon migration in hot service

A dissimilar joint held at elevated temperature over time will move carbon from the carbon steel into the higher-chromium weld metal, leaving a soft decarburised band on the carbon steel side and a hard carburised band in the weld. The joint can weaken at exactly that interface, and the effect is slow enough to be invisible until it matters. Where a stainless-to-carbon joint will run hot, a nickel-based consumable is often specified instead, because nickel alloys do not draw carbon the way high-chromium stainless does. That is a design decision, not a welding one — but it is the reason 309L is not automatically right just because the joint is dissimilar.

What POFIS supplies

ESAB E309L grades

Every grade below carries the E309L classification, which is why a WPS naming E309L 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.

**E309L grades supplied by POFIS** — typical as-welded properties. Blank cells are values the manufacturer does not publish for that grade, not zeros.
Grade	Classification	Current	Yield	Tensile	Elong.	Impact (lowest published)
OK 67.60 POFIS recommends	E309L-17 (AWS A5.4) E 23 12 L R 3 2	DC+, AC	470 MPa	580 MPa	32 %	40 J at −10 °C
OK 67.75	E309L-15 (AWS A5.4) E 23 12 L B 4 2	DC+	470 MPa	600 MPa	35 %	55 J at −80 °C
OK 67.70	E309LMo-17 (AWS A5.4) E 23 12 2 L R 3 2	DC+, AC	510 MPa	610 MPa	32 %	35 J at −20 °C

OK 67.60 E309L-17 (AWS A5.4)

The general-purpose over-alloyed electrode for welding stainless to mild and low-alloy steel and for surfacing. AC or DC, 2.0 mm to 5.0 mm. Quote this one when a joint simply needs 309L.

Diameters: 2.0 mm, 2.5 mm, 3.2 mm, 4.0 mm, 5.0 mm
Alloy type: Austenitic CrNi, over-alloyed
Type: Acid rutile coating
Source: ESAB Filler Metal Handbook, page 4-34

OK 67.75 E309L-15 (AWS A5.4)

The basic-coated grade and much the tougher: 64 J at −50 °C and 55 J at −80 °C, against 40 J at −10 °C for the rutile. DC+ only. For transition layers and dissimilar joints with real impact requirements, and for welding 24Cr-13Ni in its own right.

Diameters: 2.5 mm, 3.2 mm, 4.0 mm
Alloy type: Austenitic CrNi, over-alloyed
Type: Basic coating
Source: ESAB Filler Metal Handbook, page 4-37

OK 67.70 E309LMo-17 (AWS A5.4)

The molybdenum-bearing version, for welding acid-resistant stainless to mild and low-alloy steel and for buffer layers under 316-type cladding. Use it whenever the stainless side is 316 or 316L, so the pitting resistance carries through the joint. Also the strongest here at 510 MPa yield.

Diameters: 2.0 mm, 2.5 mm, 3.2 mm, 4.0 mm, 5.0 mm
Alloy type: Austenitic CrNi, over-alloyed with molybdenum
Type: Acid rutile coating
Source: ESAB Filler Metal Handbook, page 4-35

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 E309L grade to specify

For general dissimilar joints and cladding

OK 67.60 is the broad-coverage E309L-17: acid-rutile coated, AC or DC, 2.0 mm to 5.0 mm, with an over-alloyed deposit suited to welding stainless to mild and low-alloy steel and to surfacing. For most stainless-to-carbon work this is the electrode to quote.

Where toughness is specified

OK 67.75 is the basic-coated E309L-15, and much the tougher of the two: 75 J at room temperature, 64 J at −50 °C and 55 J still at −80 °C, against 40 J at −10 °C for the rutile grade. DC+ only. Specify it for transition layers and dissimilar joints where the procedure sets real impact requirements, and for welding 24Cr-13Ni material in its own right.

When the stainless side is 316 or 316L

OK 67.70 is the E309LMo-17 grade, over-alloyed and carrying molybdenum, for welding acid-resistant stainless steels to mild and low-alloy steel and for buffer layers under 316-type cladding. It also gives the highest strength here at 510 MPa yield. Use it rather than plain 309L whenever the molybdenum has to carry through the joint.

If the joint will operate hot

Carbon migration across a stainless-to-carbon interface at elevated temperature can weaken the joint over time. Where the service temperature is high enough for that to matter, a nickel-based consumable such as an ENiCrFe type is commonly specified in place of 309L. Send POFIS the design temperature with the enquiry and we will flag it rather than quote 309L into a joint that should not have it.

What E309L is not for

It is not a general-purpose stainless electrode. On a straight 304L-to-304L or 316L-to-316L joint, 309L deposits an unnecessarily over-alloyed, higher-ferrite weld that costs more and gives nothing in return. Use E308L or E316L to match the parent, and keep 309L for the joints that actually dilute.

Storage & handling

Storing and handling E309L consumables

Basic-coated grades need a holding oven

OK 67.75 is basic-coated and absorbs moisture like any basic electrode. Keep it sealed until use and in a holding oven once opened. ESAB packs high-alloy electrodes of 4.0 mm and above in half-package VacPac, and smaller diameters in Mini VacPac, for exactly this reason.

Check the ferrite on a clad surface

An over-alloyed deposit carries a higher ferrite number than a matching one, and where 309L is used for cladding rather than a one-off joint, the ferrite in the finished surface is usually specified and measured. Agree the acceptance range before welding starts; it is governed by the client specification rather than by the electrode.

Frequently asked

E309L — common questions

What does E309L mean?

E is a covered stick electrode; 309 is the weld metal composition, nominally 22–25 % chromium and 12–14 % nickel, which is substantially richer than the stainless it usually welds; and L means extra low carbon at 0.04 % maximum. The high chromium and nickel are deliberate over-alloying, so the deposit stays austenitic after being diluted by the carbon steel side of a dissimilar joint.

What electrode is used to weld stainless steel to carbon steel?

E309L, or E309LMo when the stainless side is 316 or 316L. The molten pool takes metal from both sides, and a matching 308L or 316L deposit diluted by carbon steel can solidify partly martensitic — hard, brittle and liable to crack. E309L starts from a richer composition so that after dilution it is still comfortably austenitic.

What is the difference between E309L and E309LMo?

Molybdenum, at roughly 2 to 3 %. Use E309LMo when the stainless side of the joint is 316 or 316L, so the deposit carries the pitting resistance that grade was chosen for. Plain E309L has no molybdenum, which means a dissimilar joint to 316L welded with it has no chloride pitting resistance at the weld.

What is a buttering layer and why use 309L for it?

A buttering layer is a first deposit laid on the carbon steel before the main joint or cladding is made. Using 309L for it lets that layer absorb the dilution from the carbon steel; once it is thick enough that later passes no longer reach the parent metal, the remaining layers can be made with the final grade — 308L or 316L — without being diluted at all. It is the standard approach for stainless cladding of carbon steel.

Can E309L be used for normal stainless steel welding?

It can, but it should not be. On a 304L-to-304L or 316L-to-316L joint, 309L deposits an unnecessarily over-alloyed, higher-ferrite weld that costs more and provides no benefit — and on 316L it would actually have no molybdenum. Match the parent with E308L or E316L, and keep 309L for joints that genuinely dilute.

Is E309L suitable for high-temperature dissimilar joints?

Not always. At elevated temperature, carbon migrates from the carbon steel into the high-chromium weld metal, leaving a soft band on one side and a hard band in the weld, and the joint can weaken at that interface over time. Where a stainless-to-carbon joint will run hot, a nickel-based consumable is commonly specified instead. Give us the design temperature and we will flag it before quoting.

Who supplies E309L electrodes in Abu Dhabi?

POFIS supplies the full ESAB OK stainless electrode range, including E309L and E309LMo, 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. Tell us both parent materials and the service conditions and we will confirm the grade before quoting. Email weldiv@pofis.ae.

Procurement & supply

Buying the E309L consumables through POFIS

The E309L 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

Price on request

Request a quotation for the E309L filler metals

Send the form and the POFIS welding division replies with pricing, confirmed lead time, delivery terms and availability. Tell us who you are and what the job is, so the reply can be specific to it rather than a catalogue price list.

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