AWS Class ERCuSn-A MIG & TIG
ERCuSn-A Phosphor Bronze TIG & MIG Welding Wire Supplier in India
Nicorex Alloys is an ISO 9001 and ISO 14001 certified supplier and stockist of ERCuSn-A phosphor bronze welding wire based in Mumbai, India. Classified under AWS A5.7 / ASME SFA-5.7, UNS W60518, and EN ISO 24373 designation CuSn6P
Also known as UNS W60518 and EN ISO 24373 designation CuSn6P. ERCuSn-A is a specialised copper-tin filler metal containing approximately 93–95% copper and 4.0–6.0% tin, and a critical 0.10–0.35% phosphorus addition acts as a potent deoxidiser. This specific chemistry is engineered to produce high-quality, porosity-free welds with distinct phosphor bronze characteristics. The 5% tin content greatly improves hardness and wear resistance, while also providing excellent protection against corrosion in seawater and tough weather conditions. Metallurgically, it offers a precise colour match to the C509xx through C519xx bronze series. These combined properties make it the preferred choice for the structural repair of tin-bronze castings, bearing surface overlays on steel substrates, gear tooth fabrication, and the manufacturing of heavy-duty marine hardware requiring high durability.
One critical property shapes every aspect of the ERCuSn-A technique. The solidus sits at 954°C (1750°F) and the liquidus at 1049°C (1920°F), creating a 95°C solidification range. That wide and soft zone makes this filler susceptible to hot cracking, so weld pools must stay small, and travel speed should remain high. TIG rods ship in 2.4 mm and 3.2 mm diameters at 914 mm length. MIG spools range from 0.8 to 1.6 mm on D200, D300, and 12-in. spools. Every batch from Nicorex Alloys ships with EN 10204/3.1B mill test certificates.
ERCuSn-A Phosphor Bronze Welding Wire Specifications
Refer to the following table for a comprehensive summary of the industrial specifications and standards governing ERCuSn-A phosphor bronze.
| AWS Classification | ERCuSn-A as per AWS A5.7 / ASME SFA-5.7 |
|---|---|
| UNS (Filler Metal) | W60518 |
| Coated Electrode (SMAW) | ECuSn-A per AWS A5.6 |
| Processes | GTAW (TIG), GMAW (MIG) |
| Polarity | (GTAW): DCEN (GMAW): DCEP (spray transfer) |
| Shielding Gas | 100% Argon or 75% He / 25% Ar |
| Welding Positions | Flat (primarily) – out-of-position difficult due to hot shortness |
| TIG Rod Diameters | 2.4 mm (3/32 in), 3.2 mm (1/8 in) |
| TIG Rod Length | 914 mm (36 in) |
| MIG Wire Diameters | 0.8, 0.9, 1.2, 1.6 mm |
| Spool Sizes | D200 (5 kg), D300 (12.5 kg), 12 in spool (30 lb) |
What Does ERCuSn-A Mean? — AWS A5.7 Classification Explained
Consult this table for a detailed explanation of the AWS A5.7 alphanumeric classification system for ERCuSn-A filler metal.
| Prefix / Suffix | Meaning |
|---|---|
| E | Electrode – for arc welding (GMAW consumable electrode) |
| R | Rod – also used as hand-fed filler rod (GTAW) |
| Cu | Copper – base element |
| Sn | Tin – principal alloying element (4–6%) |
| -A | First variant (A) in the copper-tin family within AWS A5.7 |
AWS A5.7 lists two copper-tin variants. ERCuSn-A (Alloy 518) has ~5% Sn and 50–90 HBW hardness. ERCuSn-C (Alloy 521) has 7–9% Sn and 80–120 HBW, suited to heavy overlay. There is no ERCuSn-B in AWS A5.7. Phosphorus at 0.10–0.35% acts as a deoxidiser, preventing porosity from dissolved oxygen.
Weld Deposit Chemical Composition of ERCuSn-A
Please see the following data for the precise elemental breakdown and chemical concentration limits required for ERCuSn-A weld deposits.
| Specification | Copper (Cu) | Tin (Sn) | Phosphorus (P) | Iron (Fe) | Lead (Pb) | Aluminium (Al) | Other Elements |
|---|---|---|---|---|---|---|---|
| AWS A5.7 Req. (%) | Remainder (~93–95) | 4.0–6.0 | 0.10–0.35 | 0.25 max | 0.02 max | 0.01 max | 0.50 max total |
Tin at 4–6% strengthens the copper matrix, raising hardness to 50–90 HBW (vs ~60 HBW for pure ERCu), which suits bearing overlays. Tin also improves seawater corrosion resistance and gives deposits a bronze hue matching phosphor bronze base metals. However, tin broadens the solidification range to 95°C, making deposits vulnerable to hot cracking. Lead is held to 0.02% max to prevent embrittlement.
All-Weld-Metal Mechanical Properties of ERCuSn-A
See the table below for typical tensile strength, yield strength, and elongation values of ERCuSn-A deposits.
| Specification | Tensile Strength | Elongation (% in 50 mm) | Hardness (Brinell) |
|---|---|---|---|
| Typical Value | 241 MPa (35,000 psi) min | 35% | 50–90 HBW |
Base Metal Compatibility for ERCuSn-A Welding Filler Metal
Review the following guide for various copper alloys and dissimilar metals suitable for welding with ERCuSn-A phosphor bronze wire.
| Base Metal | UNS | Notes | P-Number |
|---|---|---|---|
| Phosphor Bronze C510xx (5% Sn) | C51000, C51100 | Primary application – composition-matched | P34 |
| Phosphor Bronze C519xx (higher Sn) | C51900 | Undermatched in Sn; ERCuSn-C may suit >6% Sn | P34 |
| Tin Bronze Castings (509–519 series) | C50900–C51900 | Casting repair – preheat recommended | P34 |
| Brass (Cu-Zn alloys) | C26000, C27000 | ERCuSn-A preferred over ERCu for strength | P32 |
| Copper (deoxidised) | C12200 | Acceptable if Sn in deposit is tolerable | P31 |
| Mild Steel | P-1 | Overlay only – bronze wear surface; pulse MIG | P1 |
| Cast Iron | — | Overlay with preheat; ERCuAl-A2 may be preferred | N/A |
For higher-tin phosphor bronzes (>6% Sn), ERCuSn-C provides a better match. Keep weld pools small and peen deposits while hot.
Recommended Welding Parameters and Technique for ERCuSn-A
The table below shows how to use ERCuSn-A welding consumables and techniques for the best results.
| Process / Diameter | Current (A) | Voltage (V) | Shielding Gas | Polarity |
|---|---|---|---|---|
| GTAW (TIG) 2.4–3.2 mm | 150–250 | 15–20 | 100% Argon (15–25 L/min) | DCEN |
| GMAW (MIG) 0.9–1.2 mm | 175–275 | 24–28 | 100% Ar or 75% He / 25% Ar | DCEP (Spray) |
| GMAW (MIG) 1.6 mm | 250–350 | 26–30 | 100% Ar or 75% He / 25% Ar | DCEP (Spray) |
GMAW requires DCEP spray transfer with argon or helium-argon mixtures, while GTAW uses DCEN polarity with 100% argon shielding. Engineers must specify small stringer beads, high travel speeds, and hot peening after each pass to prevent 95°C solidification hot cracking. To ensure structural integrity, phosphor bronze base metals should be flat and preheated at 100–200°C.
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Industrial Applications of ERCuSn-A Welding Wire
The following are the industrial applications of ERCuSn-A Welding Wire
- Steel journal coating: Coat steel journals for a 50–90 HBW low-friction finish. This solves the wear issues found in heavy-duty metal contact.
- Bearing overlays: Applied to steel shafts and journals to create a 50–90 HBW low-friction surface. It provides the essential wear resistance required for heavy-duty metal-to-metal contact.
- Gear Fabrication: Utilised for repairing bronze gears and valve seats in chemical plants. It ensures long-term mechanical durability and chemical resistance in high-friction, corrosive processing environments.
- Marine Hardware: Applied to propellers and rudder fittings to prevent seawater corrosion. Unlike brass, this deposit resists dezincification, ensuring long-term reliability in submerged saltwater applications.
- Steel cladding: Applied as a protective overlay on steel pump components using pulsed MIG. It provides a cost-effective way to combine steel's strength with phosphor bronze's corrosion resistance.
- Electrical contacts: Used for welding springs and connectors. It preserves the base metal's critical electrical conductivity and spring properties while ensuring a high-strength, oxidation-resistant joint.
- Springs and connections: Welded with electrical contacts. It maintains the base metal's electrical conductivity and spring qualities while creating a strong, oxidation-resistant connection.
Storage and Handling of ERCuSn-A Phosphor Bronze Wire
Store in original packaging at 15–35°C, below 60% RH. Clean tarnished rods with acetone. Protect MIG spools from moisture. Do not contaminate with lead, sulphur, or zinc. Handle with clean gloves. No re-baking required. MTC 3.1 per EN 10204 accompanies every batch.
Available Forms, Diameters and Packaging of ERCuSn-A Welding Filler Wire
ERCuSn-A is stocked in the following forms, diameters, and packaging options.
| Form | Diameters | Packaging |
|---|---|---|
| TIG Rod (straight length) | 2.4 mm (3/32 in), 3.2 mm (1/8 in) | 5 kg / 10 lb tubes, 914 mm (36 in) length |
| MIG Spool | 0.8 (0.030 in), 0.9 (0.035 in), 1.2 (0.045 in), 1.6 mm (1/16 in) | D200 (5 kg), D300 (12.5 kg), 12 in spool (30 lb) |
How to Order AWS Class ERCuSn-A MIG & TIG from Nicorex Alloys
When ordering ERCuSn-A wire from Nicorex ALloys, please specify the following 9 details:
- AWS classification: ERCuSn-A per AWS A5.7
- Product form: TIG rod or MIG spool
- Diameter (mm or inches)
- Quantity (in kg)
- Rod length (914 mm standard) or spool size (D200 / D300 / 12 in)
- ERCuSn-A or ERCuSn-C? (specify – 5% Sn vs 8% Sn)
- Third-party approvals required (DNV, BV, Lloyds, CCS)
- Test certificate type: EN 10204 3.1 / 3.2
- Delivery destination domestic/international – specify
Nicorex Alloys stocks ERCuSn-A, ERCuSn-C, and the complete AWS A5.7 copper filler family.
Frequently Asked Questions
What is the Difference between ERCuSn-A and ERCuSn-C?
An AWS A5.7 copper-tin filler metal, ERCuSn-A, contains 4-6% Sn and 50-90 HBW hardness. ERCuSn-C possesses 80-120 HBW hardness, 7-9% Sn, and 310+ MPa tensile. Choose ERCuSn-C for heavy bearing overlays. General casting repair is easier with ERCuSn-A.
What Base Metals can ERCuSn-A Weld?
ERCuSn-A welds phosphor bronze castings in the C509xx to C519xx UNS series, brass, and deoxidised copper. It is also used for overlay on steel. It is not suited to steel-to-steel structural joints; the 241 MPa deposit is too weak for load-bearing connections.
What Shielding Gas is used for ERCuSn-A Welding?
ER5183 welding requires argon or helium-argon mixtures, maintaining flow rates of 15–25 L/min while strictly avoiding all CO₂-containing shielding gases.
Can ERCuSn-A be used as a Bearing Surface Overlay?
Yes. The 50–90 HBW deposit provides good wear resistance with low friction for journal bearings, bushings, and sliding surfaces. For heavier-duty bearing applications requiring 80–120 HBW, use ERCuSn-C. For multi-layer overlay on steel, use pulsed GMAW.
When should ERCuSn-A not be used?
Avoid ERCuSn-A for structural steel joints (241 MPa is inadequate), out-of-position welding where avoidable, high-conductivity applications (15% IACS is poor vs ERCu), and base metals with >6% Sn where ERCuSn-C is a better match.