ERCuSi-A filler metal

Harris lists 145–185 A and 23–25 V for 0.035 in Silicon Bronze wire in a GMAW electrode-positive spray-transfer row. The filler has 971°C solidus and 1027°C liquidus. Use the named process table and qualify wetting, heat and joint behavior for the actual substrate. Harris process tables

Identity and selection boundary

Lincoln's SuperGlaze SiBR brief, C4.10.21.1, June 2017, lists AWS A5.7 ERCuSi-A and ISO 24373 S Cu 6560 (CuSi3Mn1). Qualify the actual substrate and procedure. Lincoln SuperGlaze SiBR product brief

Before selecting a wire, identify the base alloys and coatings, intended joining mechanism, joint geometry, service loads and environment, and governing fabrication or repair procedure. In vehicle repair, obtain the vehicle-specific body repair instructions: I-CAR says MIG brazing must not replace a specified weld without OEM documentation. A consumable manufacturer's application list is not that documentation. I-CAR, MIG Brazing: What, Where, When, And Why?, June 25, 2019; validated in 2026

Chemistry and joining mechanisms

The Harris Silicon Bronze Welding Wire technical sheet lists copper as the remainder and silicon at 2.8–4.0%, with limits including manganese 1.5% maximum, zinc and tin each 1.0% maximum, and iron 0.50% maximum. It reports a solidus of 971°C and liquidus of 1027°C. These are filler melting-range data, not a required workpiece temperature or a permissible service-temperature rating. The accessible two-page sheet has no printed revision date. Harris technical specification

Two uses need separate process decisions:

• Copper-alloy welding: ESAB describes OK Autrod 19.30 as a copper wire alloyed with approximately 3% silicon for GMAW of copper–silicon, copper–zinc, and similar base materials. The base alloy and dilution still matter; “copper alloy” is too broad a purchasing specification.
• Arc brazing on steel: the molten filler wets the substrate while the process aims to avoid melting the base material. Miller's TIG-brazing explanation distinguishes this from fusion welding and warns that excessive base-metal melting can produce cracking. Replacing steel filler with bronze while retaining an unrelated welding procedure does not establish a sound brazing procedure. ESAB OK Autrod 19.30, Miller, TIG Brazing With Silicon Bronze, March 11, 2026

For TIG brazing, Miller describes inadequate heating as filler balling rather than wetting, and excessive heating as a cracking risk. A bronze-colored bead alone therefore does not demonstrate an adequate bond. Confirm the specified joint geometry, wetted area, and acceptance checks through the applicable procedure rather than judging appearance alone. Miller TIG brazing guidance

Process, gas, and parameter limits

Use product guidance that matches the actual joining process. ESAB normally specifies pure argon for OK Autrod 19.30. This does not authorize replacing a qualified shielding gas with a familiar steel-welding mixture. Gas selection belongs with the consumable, transfer mode, equipment program, and procedure. ESAB also lists ferritic–pearlitic steel surfacing as an application; that is a different use from joining a thin galvanized panel. ESAB product information

Use the Harris row only for its specified GMAW spray-transfer conditions. The sheet separately lists GTAW with electrode-negative DC or high-frequency AC. Qualify settings by joint design, pass count and process, especially for thin sheet. Harris process tables

Surface preparation and repair geometry

For automotive MIG brazing, I-CAR’s October 18, 2016 panel-preparation guidance applies only where the vehicle maker supplies no instructions. It recommends removing paint in the joining area, retaining as much zinc coating as possible, and following OEM corrosion-protection instructions afterward. It advises against weld-through primer because it can destabilize the arc and create porosity. This is a specific repair guidance boundary, not permission to leave every coating on every substrate. I-CAR panel preparation

I-CAR also explains that a MIG-brazed attachment may require more bonded surface area than a conventional plug weld. Follow specified hole or slot geometry instead of substituting a familiar plug-weld layout; turning up heat to imitate a fusion-weld appearance does not correct an unsuitable brazed joint. I-CAR, Common Mistakes: When MIG Brazing, May 7, 2018

Strength data and product examples

Lincoln's June 2017 SiBR brief reports average ultimate tensile strength 374.04 MPa, 0.2% yield strength 182.71 MPa, and elongation 58%. The same document explains that its results come from prescribed weld tests and should not be assumed for an actual weldment. They are not the allowable stress, fatigue strength, or peel resistance of a steel lap-brazed joint. The brief identifies ED036805 as 0.035-inch (0.9 mm) wire on a 33 lb (15 kg) spool; confirm current regional availability when ordering. Lincoln SiBR test-results and packaging information

ESAB's product page identifies both ERCuSi-A and CuSi3Mn1 classifications. That cross-reference helps identify the intended alloy family; it does not make every package, approval, or procedure interchangeable. Record the actual manufacturer, product, wire diameter, lot identification, and applicable procedure when selecting a replacement. ESAB classifications

Handling and exposure controls

Consult the exact purchased product's current regional SDS, including the base metal and coatings involved. AMPCO's manufacturer-hosted welding-products SDS J79-195, revision I, September 30, 2021 expressly includes SIL-TRODE, but covers multiple copper-alloy product families. Its broad ingredient ranges and nickel/chromium warnings must not be read as the composition of every ERCuSi-A wire. Section 3 directs readers to the individual alloy's chemistry documentation. AMPCO welding-products SDS

The SDS distinguishes solid supplied material from exposure generated during welding and brazing, and warns about fumes, arc radiation, molten metal, and electrical hazards. Provide appropriate ventilation or extraction and eye, skin, and other protection based on the actual operation. A lower-heat brazing process does not eliminate fume assessment for galvanized or otherwise coated steel. Keep the consumable identification available so exposure controls address the real alloy and substrate rather than the trade name alone. AMPCO SDS, sections 1–3

Related reference

Welding methods