Brazing is a metal-joining process where a filler metal is heated above its melting point and distributed between two or more close-fitting parts by capillary action. Unlike welding, the base metals do not melt. This allows for clean, leak-proof joints, tight tolerances, and the ability to join dissimilar metals without damaging them.
The main difference is that brazing uses a filler metal to join parts without melting the base metals, while welding melts the base metals themselves to fuse them together. Because of this, brazing is much better for joining dissimilar metals, maintaining strict part dimensions, and preventing the thermal distortion often caused by welding.
There are eight variables that determine a successful brazed joint.
Four Pre-braze Fabrication Variables
Four Brazing Process Variables
Poor yields through brazing can be traced to deficiencies in one or more of the above variables.
We primarily use copper, nickel, and silver filler metals for our furnace brazing processes. The exact filler metal we select depends on your base materials (such as carbon steel, stainless steel, or brass) and the specific operating environment your final part will face.
Annealing is a heat treatment process that softens metal to increase its ductility and reduce its hardness. You need annealing if your parts have become brittle from cold working, machining, or forming. Heating the metal and allowing it to cool slowly relieves internal stresses, making the material easier to work with for subsequent manufacturing steps.
Brazing and annealing work requires high temperatures, oxidation of the metal surface occurs in oxygen-containing atmosphere.
Oxidized surfaces form weaker bonds with the braze alloy and damage the corrosion resistance properties of stainless steels. Atmospheres blanket the parts in the furnace. Only pure atmospheres support consistently high yields and accurate defect root cause analysis.
When metals are exposed to oxygen, oxides form from oxygen atoms that attach to the metal. The oxides that form prevent the molten alloy from metallurgically joining to the metal. Also, oxides can weaken or destroy the corrosion resistance properties of stainless steel.
A bright finish on brazed and annealed parts is direct visual confirmation of the pre-braze cleanliness of parts and the quality of the atmospheres used. The brighter the part when it emerges from the furnace, the better. Clean parts and robust atmospheres are required to achieve maximum strength in brazed joints. An absolutely bright finish also assures you that the corrosion resistant quality of stainless steel parts has been preserved and maximized. You can really see the difference.
Continuous belt furnaces provide more uniform heating and cooling conditions versus batch processes. Process cycle times are shorter with minimal setup and changeover time and expense. The continuous furnace process generally requires no special tools, so startup and maintenance costs are lower. Higher quality, efficiency, and shorter cycle times make the continuous furnace process the most dependable source for Original Equipment Manufacturer’s applications.
Yes! Our process allows for brazing and annealing stainless steel parts and joining dissimilar materials. We can produce bright 400 series stainless brazed and annealed parts.
Yes. This is a natural advantage of brazing over other joining methods used for critical components. We regularly braze components with dissimilar base metals. Combinations of stainless and carbon steels are common.
Yes. Brazing is commonly used to join thinner gauge components such as tubing to heavier gauge components such as machined fittings. Often times these components are made from dissimilar base metals as well.
Yes. We specialize in flux-free, controlled atmosphere furnace brazing. This process is highly recommended for liquid cooling systems and cold plates because it completely eliminates the chemical flux residues that can contaminate coolant loops or block internal thermal management channels.
Yes. We provide comprehensive contract assembly and subassembly manufacturing directly alongside our furnace brazing services. We can integrate third-party components, install hardware and fasteners, and perform resistance welding all under one roof. By delivering a fully completed assembly, we eliminate multi-vendor transit delays and simplify your supply chain.
We specialize in high-volume, build-to-print subassemblies for the automotive, aerospace, heavy equipment, and fluid power industries. We routinely manufacture tube and fluid handling assemblies (such as hydraulic brake lines and fuel systems), thermal management loops, and custom mechanical subassemblies. We also offer full kitting and packaging services so your parts arrive line-ready.
Yes. Franklin Brazing is IATF 16949 certified for quality management. We inspect every component to meet strict customer tolerances and industry specifications, including AWS C3.6, AWS C3.14, and ASTM standards.
To get a fast and accurate furnace brazing quote, please provide us with these six details:
Base metal materials
Preferred filler metal
Part weight
Technical drawings or CAD prints with tolerances
Critical to Quality (CTQ) specifications or standards
Estimated Annual Usage (EAU)
Our high-volume furnace brazing and annealing services cater to strict, highly regulated industries. We regularly partner with OEMs and tier suppliers in aerospace (jet engine components), automotive, commercial HVAC and refrigeration, firearms, industrial fluid systems, and specialized medical/mortuary equipment.
Franklin Brazing was founded in 1973. With over 50 years of dedicated expertise in metal joining and heat treating, we have refined every aspect of the furnace brazing process to deliver the cleanest, strongest components for our partners.
Our corporate headquarters and primary processing facility are located in Lebanon, Ohio, near Cincinnati. From this centralized midwestern location, we efficiently serve manufacturing partners, supply chains, and OEMs nationwide. If you searched for brazing services near me and you are located in the midwest, then you probably found your way to our website.
Contact our team to discuss your project needs today.