4143 aluminum is a 4xxx series filler alloy with 6.8–8.2% silicon, engineered for welding and brazing applications where good fluidity and wetting are essential. It is widely used as MIG/TIG wire and brazing rod for joining 5xxx, 6xxx, and clad alloys in automotive heat exchangers and HVAC assemblies. Linsy supplies 4143 in wire, rod, sheet, tube, and bar — all backed by mill test certificates.
Moduli disponibili: welding wire / rod / sheet / tube / bar
Temperamenti comuni: O / F
Supporto per l'elaborazione: spool winding / cut-length rod / drawing / light forming
Documenti di qualità: Rapporto MTC allegato a ogni ordine
4143 aluminum (EN AW-4143 / UNS A94143) is a silicon-bearing 4xxx series alloy developed primarily as a welding and brazing filler metal. The 6.8–8.2% silicon content lowers the melting range and improves molten-metal fluidity, allowing the weld pool to wet and flow across the joint with low hot-cracking tendency.
Unlike structural 4xxx alloys such as 4032 (which is forged into pistons), 4143 is a consumable filler — it is drawn into wire and rod for joining other aluminum alloys rather than serving as a load-bearing base metal. A small magnesium addition (0.2–1.0%) lets 4143 weld 5xxx-series and 6xxx-series parts while retaining moderate post-weld strength.
The dominant form of 4143. Supplied as spooled MIG wire, cut-length TIG rod, and brazing rod. Temper O (annealed) is standard for welding consumables to ensure soft, feedable wire.
| Lega | Temperamento | Diametro (mm) | Forma |
|---|---|---|---|
| 4143 | O | 0.8–5.0 | Spool wire / cut rod |
Custom spool sizes and cut lengths available on request.
Less common than wire/rod, but available for brazed assemblies and fabricated filler components.
| Lega | Temperamento | Dimension range | Lunghezza (mm) |
|---|---|---|---|
| 4143 | F, O | Bar Ø6–80 mm / Sheet 1–50 mm t / Tube Ø10–100 mm | 1,000–6,000 |
| Standard | Denominazione |
|---|---|
| EN AW | AW-4143 |
| UNS | A94143 |
| ASTM (Wire/Rod) | B318 |
| ISO | AlSi7Mg |
| AWS (Welding) | ER4143 |
Per EN 573-3 / AWS A5.10:
| Elemento | Peso % |
|---|---|
| Si | 6.8–8.2 |
| Fe | 0.8 max |
| Cu | 0,25 max |
| Mn | 0,10 max |
| Mg | 0.20–1.0 |
| Cr | 0,10 max |
| Zn | 0.20 max |
| Ti | 0,10 max |
| Altri (ciascuno) | 0,05 max |
| Altri (totale) | 0,15 max |
| Al | Equilibrio |
Note: As a filler alloy, 4143 is characterized by its weldability and deposit properties more than by base-metal strength. The values below are for the as-fabricated (F) or annealed (O) base form.
| Temperamento | Resistenza alla trazione (MPa) | Resistenza allo snervamento (MPa) | Elongation A50 (%) |
|---|---|---|---|
| F (as fabricated) | 120–150 | 50–70 | 15–20 |
| O (ricotto) | 110–140 | 45–65 | 18–22 |
Welded joint strength depends on the parent alloy and welding procedure, not on 4143 alone. Always qualify the weld per the applicable code.
4143 welding consumables are supplied in O temper: fully soft, so MIG wire feeds smoothly through liners and TIG rod is easy to handle. This is the default for ER4143 wire and rod.
Used for extruded bar, tube, or sheet where 4143 is a component material rather than a consumable — for example, brazed assemblies or fabricated filler parts.
| Temperamento | Il migliore per | Key Advantage |
|---|---|---|
| O | Welding wire, brazing rod | Soft, feedable, low hot-crack tendency |
| F | Extruded bar/tube/sheet components | As-extruded, no extra treatment needed |
The 6.8–8.2% silicon content gives 4143 a low melting range and free-flowing molten pool. This produces smooth, defect-free welds with good tie-in to the parent metal — the primary reason it is chosen as a filler.
4143 deposits resist solidification cracking better than high-magnesium or high-copper fillers, making it a reliable general-purpose choice for joining 6xxx and 5xxx alloys.
Post-weld, 4143 deposits have moderate strength (notch-toughness and yield are lower than structural base metals). For high-strength joints, select a filler matched to the parent alloy’s strength class.
4143 has moderate corrosion resistance — similar to other silicon filler alloys. It is NOT a marine-grade alloy and should not be selected for seawater-exposed structures. For marine service, 5xxx-series fillers (e.g. 5356) are typically preferred.
4143 is a consumable alloy used wherever aluminum must be joined:
Every order from Linsy includes:
Linsy operates under ISO 9001, ISO 14001, and ISO 45001 management systems. Production lead times range from 10 to 60 days depending on product form and order complexity.
Linsy Aluminum supplies welding and brazing filler alloys to fabrication shops, heat-exchanger manufacturers, and industrial buyers worldwide. For 4143 alloy:
Learn more about aluminum welding fillers and brazing:
4143 is a welding and brazing filler alloy (ER4143). It is drawn into MIG/TIG wire and brazing rod for joining 5xxx, 6xxx, and clad aluminum alloys — common in automotive radiators, HVAC coils, and general fabrication.
No. 4143 is a wrought filler alloy, not a casting alloy. Casting fillers and casting alloys belong to the 3xx series. 4143 is consumed as wire/rod during welding and brazing.
Not as a first choice. 4143 has moderate corrosion resistance and is not marine-grade. For seawater-exposed welded structures, a 5xxx-series filler such as 5356 is usually specified. Confirm with your welding procedure.
Welding wire and rod are supplied in O temper (annealed, soft) for smooth feeding and handling. F temper applies to extruded bar/tube/sheet forms used as components.
4043 has slightly lower silicon (4.5–6.0%) and no intentional magnesium; 4143 has higher silicon (6.8–8.2%) and 0.2–1.0% Mg. The magnesium in 4143 gives somewhat higher post-weld strength, making it suitable where the joint sees light load. For maximum ductility, 4043 is often preferred.
MOQ depends on form. Welding wire spools typically have a lower MOQ than extruded bar. Contact Linsy for specifics.
Common MIG diameters 0.8–1.6 mm; TIG rod 1.6–5.0 mm. Other sizes on request.
Every shipment includes a Mill Test Certificate (MTC) with chemical composition. SGS third-party reports are available on request.
Production lead time is 10–60 days depending on product form, dimensions, and order quantity.
Yes. Linsy supplies aluminum products to buyers worldwide. Shipping terms and freight options are confirmed during order placement.
Vantaggi Linsy
Linsy Aluminum è un fornitore leader di prodotti per la lavorazione dell'alluminio, che serve diversi settori, tra cui quello aerospaziale, dell'ingegneria generale, automobilistico, marittimo, navale e altre applicazioni industriali specializzate.
Ci impegniamo a mantenere i più alti standard di qualità e responsabilità ambientale, come dimostrano le nostre certificazioni: ISO 9001:2008, ISO 14001:2004 e SGS.
