AWS Class ERCuSi-A MIG & TIG
ERCuSi-A Silicon Bronze TIG Filler Rod & MIG Wire Supplier in India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified Mumbai-based supplier and stockist of ERCuSi-A silicon bronze welding wire and TIG rod. We provide these rods and wires classified under AWS A5.7 / ASME SFA-5.7.
ERCuSi-A is the standard copper-silicon filler metal for MIG brazing galvanised steel, TIG welding copper alloys, and oxy-fuel braze-welding cast iron. The wire carries a nominal Cu–93%, Si–3%, Mn–1% balance that drops the solidus to 910°C (1670°F), below steel’s melting point. That lower melting range lets MIG brazing bond zinc-coated panels without destroying the galvanised coating. It is also identified as UNS C65600, Werkstoff Nr. 2.1461, CuSi3Mn1. As-welded deposits reach 345 MPa (50 ksi) tensile strength, 40% elongation, and 80 HB hardness at a density of 8.5 kg/dm³. Processes include GTAW (DCEN/ACHF), GMAW (DCEP), OFW, and PAW.
Silicon bronze is inherently hot short, so stringer beads, fast travel speed, and a strict 65°C (150°F) interpass ceiling are mandatory to prevent cracking. ERCuSi-A TIG rods ship in 1.6, 2.4, and 3.2 mm diameters at 914 mm (36″) length; MIG spools in 0.8, 0.9, 1.0, 1.2, and 1.6 mm. Compatible base metals span copper-silicon alloys (P-35), brass, galvanised steel (P-1), and cast iron. It is mainly applied in industries that include automotive panel brazing, HVAC ductwork, marine hardware, art and sculpture, cast iron repair, and corrosion-resistant surfacing. All shipments carry EN 10204/3.1B mill test certificates.
ERCuSi-A Welding Wire Specifications
ERCuSi-A welding wire specifications covering classification, standards, process compatibility, and available diameters are listed below:
| AWS Classification | ERCuSi-A (AWS A5.7) |
|---|---|
| UNS Number | C65600 |
| Welding Processes | GTAW (TIG), GMAW (MIG), OFW, PAW |
| Polarity | (GTAW): DCEN or ACHF (GMAW): DCEP |
| Welding Positions | All (flat, horizontal, vertical, overhead) |
| Shielding Gas | (GTAW): 100% Ar or He (GMAW): 100% Ar or Ar + 1% O₂ |
| TIG Rod Diameters | 1.6, 2.4, 3.2 mm |
| MIG Wire Diameters | 0.8, 0.9, 1.2, 1.6 mm |
| Standard TIG Rod Length | 914 mm (36″) |
AWS Classification Explained: What Does ERCuSi-A Mean?
The AWS Classification of ERCuSi-A wire is explained in the table below, along with the designation and meaning:
| Designation | Meaning |
|---|---|
| ER | Electrode/Rod (bare solid wire for GTAW, GMAW, OFW) |
| Cu | Copper base |
| Si | Silicon as principal alloying element (approx. 2.8–4.0%) |
| -A | Standard variant |
ERCuSi-A is a silicon bronze filler metal widely used for welding galvanised steel, brass, and dissimilar joints due to its excellent fluidity and low cracking tendency. It is also classified as RCuSi-A under AWS A5.27 for brazing applications, ensuring cross-process compatibility.
Chemical Composition of ERCuSi-A Wire per AWS A5.7
The chemical composition of ERCuSi-A wire, along with its proportion in percentage, is listed in the table below:
| Specification | Copper (Cu) | Silicon (Si) | Manganese (Mn) | Tin (Sn) | Zinc (Zn) | Iron (Fe) | Aluminium (Al) | Lead (Pb) | Other Elements (total) |
|---|---|---|---|---|---|---|---|---|---|
| AWS A5.7 Req. (%) | Balance (~92.5) | 2.8–4.0 | 1.50 max | 1.00 max | 1.00 max | 0.50 max | 0.01 max | 0.02 max | 0.50 max |
Silicon at 2.8–4.0% lowers the solidus to ~910°C and forms a protective SiO₂ film. Manganese deoxidises the pool and adds strength. Lead and aluminium are held to trace levels; lead causes hot cracking; aluminium forms refractory Al₂O₃ inclusions.
Mechanical Properties of ERCuSi-A Weld Deposits
The mechanical properties of the ERCuSi-A weld deposit, including tensile strength, elongation and more, are listed below:
| Specification | Tensile Strength | Elongation (in 50 mm) | Brinell Hardness | Shear Strength (approx.) |
|---|---|---|---|---|
| Typical Value | 345 MPa (50,000 psi) | 40% | 80 HB | ~210 MPa |
Deposits are not heat-treatable. Strength derives from solid-solution strengthening by silicon and manganese.
Base Metal Compatibility for ERCuSi-A Silicon Bronze Wire
The base metal and its compatibility, along with the grade and ASME number, are listed in the table below:
| Base Metal | Grade | ASME P-No. | Notes |
|---|---|---|---|
| Cu-Si Bronze | C65100, C65500 | P-35 | Primary matching application |
| Brass | C26000, C27000, C28000 | P-32/33 | Keep the weld pool small; zinc fume risk |
| Pure Copper | C11000, C12200 | P-31 | Preheat 200–425°C for heavy sections |
| Low-Al Bronze (<3% Al) | — | P-35 | Not suitable for high-Al (>8%) bronze |
| Carbon Steel | A36, A516 | P-1 | MIG brazing; no true fusion |
| Galvanised Steel | — | P-1 | Helps preserve zinc coating |
| Cast Iron | Grey, Ductile | — | Preheat ~315°C; use stringer beads |
| Stainless to Carbon Steel | — | P-8 / P-1 | Dissimilar brazing with low heat input |
ERCuSi-A is classified under ASME SFA-5.7 with F-Number 32 as per Section IX (QW-432). A-Number classification is not assigned, since QW-442 applies only to ferrous weld metal deposits and excludes copper-based fillers.
Recommended Welding Parameters for ERCuSi-A TIG & MIG Wire
Use these ERCuSi-A TIG and MIG settings to keep the weld pool small, cool quickly, and minimise hot-short cracking risk:
GTAW (TIG) — DCEN / ACHF
| Wire Dia. | Amps DC (A) | Amps AC (A) | Gas | Flow |
|---|---|---|---|---|
| 1.6 mm | 70–150 | 70–150 | 100% Ar or He | 15 cfh |
| 2.4 mm | 150–200 | 140–230 | 100% Ar or He | 15 cfh |
| 3.2 mm | 230–400 | 225–320 | 100% Ar or He | 20 cfh |
GMAW (MIG) — DCEP, Spray Transfer
| Wire Dia. | WFS (ipm) | Amps (A) | Volts (V) | Flow |
|---|---|---|---|---|
| 0.8 mm | 460–500 | 130–150 | 21–23 | 25 cfh |
| 0.9 mm | 400–440 | 145–185 | 23–25 | 30 cfh |
| 1.2 mm | 280–310 | 195–215 | 26–28 | 30 cfh |
| 1.6 mm | 150–210 | 260–280 | 27–30 | 40 cfh |
For MIG brazing galvanised steel, use 100% Ar or Ar + 1% O₂. Interpass must stay below 65°C (150°F). Stringer beads only, no weaving.
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Industrial Welding Applications of ERCuSi-A Silicon Bronze Filler Wire
ERCuSi-A silicon bronze welding wire offers low-heat, crack-resistant joining and overlay performance on copper alloys, steels, and cast irons.
- Automotive and transportation – Used to braze galvanised steel panels and door frames.
- HVAC, sheet metal & general fabrication – Applied on galvanised ductwork and steel enclosures.
- Marine & offshore hardware – Used to weld copper-silicon fittings and brass valve bodies.
- Art, sculpture and decorative metalwork – ERCuSi-A TIG rod is used for bronze sculptures and decorative pieces.
- Cast iron repair & maintenance – Braze-weld cracked grey iron manifolds with ERCuSi-A at lower heat input than steel fillers.
- Corrosion-resistant surfacing & overlay – ERCuSi-A wire is also used to apply a bronze overlay on steel surfaces.
Storage and Handling of ERCuSi-A Silicon Bronze Welding Wire
No heated storage needed. Keep sealed packaging in a dry, clean area. For MIG, use U-groove rollers, a nylon or PTFE liner, and an oversized contact tip. Clean TIG rods with acetone before use. On galvanised steel, degrease but do not strip the zinc coating.
Available Forms, Diameters and Packaging of ERCuSi-A
Nicorex Alloys stocks ERCuSi-A silicon bronze wire in the forms, diameters and packaging listed below:
| Form | Diameter | Packaging |
|---|---|---|
| TIG Rod | 1.6, 2.4, 3.2 mm | 1 lb / 2.5 kg / 5 kg / 10 lb tubes; 914 mm length |
| MIG Spool | 0.8, 0.9, 1.2, 1.6 mm | 1, 2, 5, 7, 12.5, 15 kg spools (D100/D200/D300) |
| Drum | 0.9, 1.2 mm | 200 kg / 250 lb drums for production lines |
All shipments include MTC 3.1 per EN 10204. Classification certificates (CCS, DNV, BV, LR, NK, KR, RS) available on request.
How to Order ERCuSi-A Silicon Bronze MIG & TIG Filler Metal from Nicorex Alloys
To order ERCuSi-A Silicon Bronze TIG Filler Rod & MIG wire from Nicorex Alloys, provide these 10 important details:
- Wire Type: GTAW/GMAW AWS A5.7 ERCuSi-A
- Size: 1.6mm-3.2mm cut lengths, 0.8mm-1.2mm spools
- Current Type: DCEN/DCEP + 100% Argon gas
- Welding Position: All positions
- Material Grade: C65600 / ERCuSi-A / 2.1461 / ISO 24373
- Quantity: 5kg tubes / 15kg spools
- Standard: AWS A5.7 / ASME SFA 5.7
- Documentation: MTC EN 10204 3.1, TPI report
- Packaging: Rigid tubes and vacuum-sealed foil bags
- Delivery Destination: Domestic
Frequently Asked Questions
What is the price of ERCuSi-A Silicon Bronze Welding wire per Kg in India?
ERCuSi-A pricing varies by form, diameter, volume, and copper market rates. Silicon bronze costs more than ER70S-6 but less than nickel alloy wires. Contact Nicorex Alloys for current per-kg rates.
Why is ERCuSi-A preferred for MIG Brazing Galvanised Steel instead of ER70S-6?
ERCuSi-A melts at 910–1025°C, below steel’s ~1500°C melting point, so it wets the surface without melting the base metal, and the zinc layer stays intact. ER70S-6 melts the steel, vaporises zinc, and destroys corrosion protection.
What causes Hot-Short Cracking with ERCuSi-A, and how is it prevented?
Silicon bronze has near-zero ductility in the semi-solid range during solidification. This can be prevented using stringer beads, a small pool, high travel speed, interpass below 65°C (150°F), and no weaving.
What is the difference between ERCuSi-A and ERCuSn-A for Bronze Welding?
ERCuSi-A (Cu–3Si) excels on brass, galvanised steel, and MIG brazing. ERCuSn-A (Cu–5Sn) targets tin-bronze base metals and bearing overlay. Use ERCuSi-A for steel and brass; ERCuSn-A when the base contains 5–8% tin.
What is the F-Number of ERCuSi-A per ASME Section IX?
F-Number is 32 per QW-432. A-Number is not applicable (ferrous deposits only). SFA is 5.7.
Can ERCuSi-A be used for TIG Braze-Welding cracked Cast Iron?
Yes. Preheat to 315°C (600°F), use short stringer beads, keep the pool small, and peen each pass while hot. The gold/bronze deposit is effective for manifolds, machine bases, and vintage automotive parts.