KappZappA™ - Acid Flux Cored Silver Solders for Stainless Steel to Stainless Steel and Copper

KappZappA™ solders contain a central core of acidic soldering flux to break the oxide layer and promote a strong metallic bond between the solder and parts.

The acid core is designed specifically for soldering Stainless Steel and Copper parts, producing strong and ductile joints. The resulting joints have high tolerance to vibration and stress, with tensile strengths to 33,000 psi on Stainless. The flux residue can be removed with warm water or alcohol and a clean rag.


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Benefits and Uses

KappZappA™ Acid-cored Solders are used in structural applications on Stainless Steel and Copper. Low melting temperatures prevent loss of properties and minimize distortion on thin parts and sheets. KappZappA™ Tin-Silver alloys are used for fabrication, ducting, food containers, storage bins, instruments, Copper plumbing pipe, and cooling coils for refrigerators. This alloy and flux are Food and Potable Water Safe and are used throughout the food processing industry for the manufacture and repair of Stainless Steel parts and components.

In many instances, a stronger overall assembly exists after joining with KappZappA™ Tin-Silver solder than with higher temperature Silver brazing alloys. The most popular of the low temperature Silver bearing acid-cored solders is KappZapp3.5AC™ - 96.5% Tin, 3.5% Silver with a 3% Acid-Core.

Kapp Alloy also produces solid wire Tin-Silver solders with up to 7% Silver for applications requiring a higher temperature range and/or higher Silver content for superior strength and vibration resistance.

The following chart illustrates the properties of KappZapp3.5AC soldered joints. Many factors, such as materials, temperature, and method of application determine the solder joint strength and characteristics. Call Kapp for engineering assistance to discuss your specific needs. We recommend testing appropriate alloys in your specific application to ensure suitability. Samples of Kapp alloys are always available upon request.

Physical Properties & Technical Data
Composition 96.5Sn - 3.5Ag
Solidus(°F) /(°C) 430°F / 221°C
Liquidus(°F) /(°C) 430°F / 221°C
Tensile Strength (copper) 14,000 psi
Tensile Strength (stainless) 25,000 psi
Shear Strength 11,600 psi
Elongation 48%
Electrical Conductivity (%IACS) 16.4

All KappZapp™ solid solders are available in bar or wire form. Custom alloys and forms are our specialty.