AWS Class ER4043 MIG & TIG
ER4043 Aluminium Welding Wire - TIG Filler Rod & MIG Wire Supplier in India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified Mumbai-based supplier, importer and stockist of ER4043 aluminium welding wire classified under AWS A5.10 / ASME SFA-5.10.
ER4043 is an aluminium-silicon welding wire containing 4.5-6.0% silicon. This silicon lowers the melting point, makes the weld pool more fluid, and reduces the risk of hot cracking when welding 1XXX, 3XXX, and 6XXX wrought alloys, as well as cast grades like A356, A357, 319, and 443. The wire produces smooth, bright beads with very little spatter and is one of the easiest aluminium fillers to weld. Weld deposits are not heat-treatable. On 6061-T6, typical as-welded tensile strength is about 170 MPa (24.5 ksi) with 8% elongation. TIG rods are available in 1.6, 2.4, 3.2, and 4.0 mm diameters at 1000 mm length. MIG wire comes in 0.8, 1.0, 1.2, and 1.6 mm on D100, D200, and D300 reels. ER4043 is used with AC for TIG (GTAW) and DCEP for MIG (GMAW), with 100% Argon or Argon/Helium shielding.
Also known as 4043 aluminium filler wire, AlSi5 TIG rod, Al-Si welding wire, and UNS A94043. It is the most commonly used aluminium filler wire for general TIG (GTAW) and MIG (GMAW) welding. ER4043 aluminium welding wire is commonly used for 6xxx alloys, automotive parts, and heat exchangers because it flows easily, resists cracking and produces clean, smooth-looking welds.
ER4043 Welding Wire Specifications
ER4043 specifications listed below cover classification, processes, polarity, shielding gas and diameters.
| AWS Classification | ER4043 |
|---|---|
| Specification | AWS A5.10 / ASME SFA-5.10 |
| UNS Designation | A94043 |
| Welding Processes | GTAW, GMAW, SAW |
| Polarity | (GTAW): AC (preferred) or DCEP (GMAW): DCEP |
| Positions | All |
| Shielding Gas | (GTAW): 100% Argon; Ar/He for thick sections (GMAW): 100% Argon or 75Ar/25He |
| TIG Rod Diameters | 1.6, 2.4, 3.2, 4.0 mm |
| MIG Wire Diameters | 0.8, 1.0, 1.2, 1.6 mm |
| TIG Rod Length | 1000 mm (36″) |
AWS Classification Explained: What Does ER4043 Mean?
The AWS A5.10 code is made of two parts that describe what the wire does and which alloy it is.
| Designator | Meaning |
|---|---|
| ER | Electrode/Rod — dual-purpose bare wire for GMAW (electrode) and GTAW (rod) |
| 4043 | Aluminium Association alloy — 4XXX series (Al-Si); 4.5–6.0% silicon |
In 4XXX alloys, silicon lowers the freezing range of the weld and helps prevent hot cracks. ER4047 has about 12% silicon, ER5356 uses 5% magnesium for higher strength, and ER2319 adds 6.3% copper for heat-treatable aerospace joints.
Chemical Composition of ER4043 Wire per AWS A5.10
This table shows the required chemical composition of ER4043 welding wire under AWS A5.10, including each element and its allowed percentage range.
| Specification | Silicon (Si) | Iron (Fe) | Copper (Cu) | Manganese (Mn) | Magnesium (Mg) | Zinc (Zn) | Titanium (Ti) | Beryllium (Be) | Aluminium (Al) | Other (each / total) |
|---|---|---|---|---|---|---|---|---|---|---|
| AWS A5.10 Req. (%) | 4.5–6.0 | 0.80 max | 0.30 max | 0.05 max | 0.05 max | 0.10 max | 0.20 max | 0.0003 max | Remainder | 0.05 / 0.15 max |
The very low magnesium limit (0.05% max) is deliberate. It makes ER4043 safe for heat-treatable 6XXX alloys, because too much magnesium in the filler can increase the risk of cracking.
Mechanical Properties of ER4043 Weld Deposits
The following table presents typical mechanical properties of ER4043 weld deposits on 6061-T6 aluminium, based on as-welded conditions.
| Specification | Tensile Strength | Yield Strength | Elongation | Shear Strength (fillet weld) |
|---|---|---|---|---|
| AWS A5.10 Minimum | 170 MPa (24.5 ksi) | 70 MPa (10 ksi) | 8% | 117 MPa (17 ksi) |
On 6061-T6, the weld area becomes soft and weaker than the 310 MPa T6 base metal, and the HAZ always loses its T6 temper. For maximum as-welded tensile strength on 5XXX alloys, use ER5183 or ER5356.
Base Metal Compatibility for ER4043
This table shows which aluminium base metals are compatible with ER4043 filler wire, along with suitable alloy grades and recommended usage.
| Base Alloy Series | Specific Alloys | P-Number | Notes |
|---|---|---|---|
| 1XXX (Pure Al) | 1100, 1350 | P-21 | ER4043 or ER1100 |
| 3XXX (Al-Mn) | 3003, 3004, 3005 | P-21 | ER4043 preferred |
| 4XXX (Al-Si) | 4043, 4047 | P-22 | Matching filler |
| 5XXX (<3% Mg) | 5005, 5050, 5052 | P-22 | ER4043 acceptable |
| 6XXX (Al-Mg-Si) | 6005, 6061, 6063, 6082, 6351 | P-23 | ER4043 preferred for crack resistance |
| Cast Al-Si | 356, A356, A357, 319, 443 | — | ER4043 ideal |
Avoid using ER4043 with alloys 5083, 5086, 5454, 5456, 2014, 2219, 7005, and 7039. Instead, use ER5356 or ER5183 for 5XXX, and ER2319 for 2014/2219. ER4043 has an F-Number 22 (SFA-5.10). A-Number is not applicable.
Recommended Welding Parameters for ER4043 TIG & MIG Wire
This table shows recommended settings for ER4043 TIG and MIG wire to help you get a stable arc and consistent weld quality.
GTAW (TIG) — AC Polarity Preferred:
| Wire Diameter | Amperage (A) | Voltage (V) | Gas |
|---|---|---|---|
| 1.6 mm (1/16″) | 60–110 | 12–16 | 100% Argon |
| 2.4 mm (3/32″) | 100–170 | 14–18 | 100% Argon |
| 3.2 mm (1/8″) | 140–240 | 16–22 | 100% Argon |
GMAW (MIG) — DCEP:
| Wire Diameter | Amperage (A) | Voltage (V) | WFS (m/min) | Gas |
|---|---|---|---|---|
| 0.8 mm | 60–120 | 16–22 | 6–12 | 100% Argon |
| 1.0 mm | 80–160 | 18–24 | 6–14 | 100% Argon |
| 1.2 mm | 120–250 | 20–28 | 6–16 | 100% Argon |
Before welding, scrub off oxide with a stainless steel brush and clean with acetone. For sections over 12 mm, use a 75% Argon / 25% Helium mix and a push technique for MIG.
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Industrial Welding Applications of ER4043 Filler Wire
ER4043 filler wire is widely used in many industries because it flows smoothly, is less likely to crack, and works well for welding and repairing aluminium parts.
- Automotive: ER4043 is widely applied for welding structural aluminium components, body panels, engine blocks, transmission housings, radiator sections and exhaust heat shields.
- General Fabrication: In fabrication shops, it is utilised for aluminium furniture, frames, enclosures, architectural profiles, handrails and window frames.
- HVAC: It works well for aluminium ductwork, heat exchangers, evaporator coils and condenser assemblies.
- Food and Beverage: It handles aluminium tanks, piping and vessels in non-corrosive processing environments.
- Repair Welding: It is applied for restoring cast aluminium components such as pump housings, engine blocks, valve bodies and impellers by effectively filling porosity and other defects.
- Brazing: Commonly selected as the filler metal for 1100 and 3003 aluminium assemblies in HVAC equipment and heat exchanger manufacturing.
- Electrical: Used for welding aluminium busbars and conductors where good electrical conductivity and reliable joints are required.
Storage and Handling of ER4043 Aluminium Welding Wire
Store the wire in its original sealed packaging at 15-30°C, with humidity below 60% RH. Because aluminium oxide reforms within seconds, clean the wire and base metal right before welding. Keep spools away from oils and cutting fluids, as hydrocarbon contamination can cause porosity. Use U-groove drive rolls with nylon or Teflon MIG gun liners. Choose contact tips that are 0.1-0.2 mm larger than the wire diameter. The wire has an indefinite shelf life if the packaging remains sealed.
Available Forms, Diameters and Packaging of ER4043 Filler Wire
ER4043 filler wire comes in different forms, sizes, and packaging to suit various welding methods and job requirements.
| Form | Diameters | Packaging |
|---|---|---|
| TIG Rod (GTAW) | 1.6, 2.4, 3.2, 4.0 mm | 2.5 kg / 5 kg tubes; 1000 mm cut lengths |
| MIG Spool (GMAW) | 0.8, 1.0, 1.2, 1.6 mm | 0.5, 2, 5, 7 kg spools (D100/D200/D300); 15 kg bulk on request |
All wire comes with MTC 3.1 certificates as per EN 10204. Custom packaging is available on request.
How to Order ER4043 Welding Wire from Nicorex Alloys
Specify the following details in your order when placing an order for ER4043 welding wire from Nicorex Alloy:
- Wire Type: GTAW/GMAW ER4043 (AWS A5.10)
- Size: 0.8-2.4 mm, spool/cut length
- Current Type: DCEN/DCEP with Argon shielding gas
- Welding Position: Flat, horizontal, vertical, overhead
- Material Grade: UNS A94043, EN ISO AlSi5
- Quantity: Spool weight or cut length kg
- Standard: AWS A5.10, ASME SFA 5.10
- Documentation: MTC EN 10204 3.1
- Packaging: Spool or rigid tube/box
- Delivery Destination: Domestic or international
Frequently Asked Questions
What is the price of ER4043 welding wire per kg in India?
Pricing depends on the product form, wire diameter, order quantity and current aluminium prices. Contact Nicorex Alloys for a quote with MTC 3.1 documentation.
What is the difference between ER4043 and ER5356 for welding 6061 Aluminium?
ER4043 (Al-5% Si) flows better, cracks less, and gives higher fillet shear strength. ER5356 (Al-5% Mg) has higher tensile strength, better ductility, improved saltwater corrosion resistance and anodised colour match.
Why does ER4043 produce a dark weld after anodising?
The 5% silicon in ER4043 does not anodise evenly with the aluminium. This causes the weld to appear dark grey compared to the base metal.
What is the F-Number for ER4043 per ASME Section IX?
R4043 under SFA-5.10 has F-Number 22, as listed in QW-432. A-Number does not apply because QW-442 is only for ferrous weld metals.
When should ER4043 not be used?
Do not use ER4043 with 5XXX alloys containing more than 3% magnesium, in anodised joints needing colour match, at temperatures above 65°C where stress corrosion is likely, in cryogenic service below -196°C, or on 2XXX aerospace alloys without approval.