Aufhauser SpeedFlux is specially formulated for manual or automated torch brazing applications. The flux is solvent-based to incorporate vapor into oxy-acetylene or liquefied petroleum gases (LPG) used for the heat source. SpeedFlux exerts powerful scavenging action on most metal oxides, removing tarnish, scale, and other impurities to yield strong fillet joints. This property of the flux keeps base-metals clean, saving time and reducing costs for post-braze cleaning.

SpeedFlux is ideally used in high-speed production processes for braze-welding steel and other metals with bronze rods, nickel-silver rods and silver solders.

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SpeedFlux is formulated to meet manufacturing process and application requirements for brass, bronze, and steel tube and flange joints for air conditioning, refrigeration, medical and many other end-products.

  • All surface brazing applications
  • Tubular steel furniture
  • Building up shafts and spindles
  • Automotive manufacturing and body shops
  • Copper brazing on heat exchangers
  • Repairing bronze castings
  • Bicycle manufacturing and repair
  • Sculpture
  • Jewelry - gold and silver products
  • Ornamental fabrication
  • General maintenance shops
  • HVAC & refrigeration
  • Brass plumbing components


    ANSI/AWS A5.31-92, FB3-K A6.14 FB3-K is a liquid flux used almost exclusively in torch brazing. The fuel gas is passed through the container of liquid flux entraining flux in the fuel gas. The flux is applied by the flame where needed on base metals such as carbon steels, low alloy steels, cast iron, copper and copper alloys, nickel and nickel alloys, and precious metals. The flux consists primarily of liquid borates.

      SpeedFlux 30 SpeedFlux 50 SpeedFlux 70
    Form Clear Liquid Clear Liquid Clear Liquid
    Specific Gravity 0.830 ± 0.02 0.865 ± 0.02 0.885 ± 0.02
    Flash Point Closed Cup -7.7°C/18°F -7.7°C/18°F 12°C/54°F
    Freezing/Melting Point -32°C/-26°F -32°C/-26°F -32°C/-26°F
    Freezing Effects None None None
    Active Temperature Range 1400-2000°F
    Post Braze Residues Water-Soluble Water-Soluble Water-Soluble

    One U.S. Gallon of SpeedFlux will process from 2500-3000 cubic feet of acetylene.

    Available in 1 gallon can, 5 gallon pail, and 53 gallon drum.


    SpeedFlux is a boron infused liquid flux which is vaporized and inducted into the fuel gas stream automatically. The SpeedFlux dispenser picks up the flux in vapor form and delivers it to the torch in the gas - thus the flux is in the flame, evident by the green color. The use of SpeedFlux assures exactly the right amount of flux, applied automatically. No glassy residue is formed. Finishing costs such as filing or grinding are practically eliminated. As the flame contacts the metal part, the flux in the flame cleans and fluxes the parent metal. The use of blue-tinted goggles is recommended as these enable the green SpeedFlux flame to be more easily seen and adjusted, see picture below.

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    SpeedFlux should be poured into a flux dispensing unit that is used for automated introduction of the SpeedFlux vapors into the gas-line. Recommended gases are oxy-acetylene or liquefied petroleum. SpeedFlux is active between 1400-2000°F/760-1100°C, which makes it an optimum choice for use with a variety of Aufhauser BCuP PhosCopper, BAg Silver Brazing, and CDA low-fuming bronze filler alloys.

    • Remove any oil, grease, or other contaminants from the surface to be brazed.
    • Once the flame is set properly for application, point torch to area/joint being brazed. Green flame confirms that flux is in the flame.
    • Apply heat/flux simultaneously with torch to area/joint being brazed.
    • After sufficient preheat, determined by joint and process, feed braze alloy into the joint, unless a brazing pre-form is already in place.
    • The flame should be "soft" and used like a brush to keep the deposited metal flowing.
    • Clean post-braze flux residues from brazed joint using hot water 60°C ± 5°C / 140°F ± 10°F.



    SpeedFlux is a flammable, hazardous product, and should be handled and stored as an industrial chemical. Store containers away from heat, sparks, or open flame. All packaging used for this flammable chemical is UN Rated. Storage for this product should meet local or state standards for flammable rated products.

    Adequate ventilation is necessary to remove flux fumes along with vapors and fumes from brazing process area. Wear NIOSH approved gloves, welding goggles with dark coated brightness lenses, and respirators when working with this product. Avoid breathing vapors and contact with skin, eyes and mucous membranes.

    Refer to SDS for additional safety and storage information.

    Due to the rapid evaporation rate of SpeedFlux seal all containers very tightly once opened to prevent loss of solvents.

    Fully or partially consumed SpeedFlux containers remain hazardous when void. Since empty containers retain product residues, vapor or liquid, all labeled hazardous precautions must be observed. Do NOT flame cut, braze or weld empty container. Do NOT reuse empty package without proper industrial cleaning or reconditioning. Store empty containers away from heat, sparks, and flame.

    The information contained herein is based on data considered to be accurate and is intended for use by persons having technical skills at their own discretion and risk. Since conditions of use are outside of Aufhauser Corporation's control, we cannot assume liability for results obtained or damage incurred due to misuse, nor can we assume customer liability.