Important Announcement for our Valued Customers

For almost 100 years, Automatic Machine Products has manufactured high quality machined components to a variety of industries. Since the 1940s, AMP has manufactured the highest quality brass and steel refrigeration service valves in HVAC industry. Throughout the decades, AMP has adapted to serve the requirements of its valued customers. Today, we are excited to announce another strategic change to meet today’s business needs.

Due to the global supply chain crisis, the industry has seen a significant shift towards domestically sourced manufactured goods. AMP has been working hard to meet the needs of our machined part customers’ increased demand for critical components.

With careful consideration, AMP has re-evaluated its overall business model and, come to the determination that it would divest itself of a significant product line. While retaining brass refrigeration valve manufacturing, AMP will move away from the steel refrigeration valve business. This move allows the company to free up considerable resources and capacity to better serve the machined component and brazing businesses going forward.

This change will allow AMP to better meet the needs of its current and future customers with much needed increased capacity and shorter lead times for high quality, domestically sourced and cost-effective precision machined parts, furnace brazing and assemblies.

With this new focus, AMP looks forward to relieving some of the supply chain burdens of its valued customers, old and new.


For more information, contact:

Dan Gramm

Director of Business Development

Automatic Machine Products

Controlled Atmosphere Furnace Brazing for Cost-Effective Assembly

Controlled Atmosphere Furnace Brazing for Cost-Effective Assembly

Steel valves going into controlled atmosphere brazing furnace

Steel refrigeration valves going into controlled atmosphere brazing furnace at Automatic Machine Products

Manufacturers have a selection of options for joining metals: fasteners, adhesives, soldering, welding, and brazing. Fasteners are preferable when the product may have to be disassembled later. Adhesive and solder are fine when high strength or temperature resistance is not required. Welding and brazing produce permanent joints that resist leaks, vibrations, and shocks.

Brazing gets the nod over welding in many instances. First of all, unlike welding, brazing can successfully join dissimilar metals. It works extremely well in high-production projects. Also, brazing offers strong joints and works with thick and thin metals.

Brazing is not a new process. Archaeologists have dug up evidence showing that it dates back to at least ancient Egypt. And over the centuries since then, brazing has established its place in an industrialized world. 

Brazing lends itself to an array of materials including mild steel, stainless steel, cast iron, nickel, aluminum, copper, brass, and bronze. Even ceramics, magnesium, and titanium can be brazed. And its list of applications is extensive. Here’s a small sample:

  • Metal housings
  • Electro-mechanical assemblies  
  • Pipe fittings 
  • Plumbing fixtures
  • Automotive engine components
  • HVAC system components

The list of applications is almost endless, and there are several methods for achieving a high-quality braze. If a project calls for quantities, you should understand continuous controlled atmosphere brazing.

What is controlled atmosphere brazing? 

Steel valves entering continuous atmosphere controlled brazing furnace

High volumes of parts can be brazed with extreme consistency with continuously fed brazing furnaces.

Brazing manually with a torch in an open-air atmosphere can overheat, weaken and oxidize the base metal, resulting in weak joints and unsightly cosmetic appearance. When flux is used to prevent oxidation, residue and flux voids are always a possibility.

Controlled atmosphere furnace brazing prevents localized overheating and damage to the metal, allowing the filler material to melt correctly and flow into the joints—all without flux! And in some cases, the metal parts come out of the furnace looking shinier than when they went in. This brazing process is done in large quantities inside the “controlled atmosphere” of a furnace. There are two options for this process: inside a vacuum chamber with sealed doors and a continuous-belt furnace without doors.

The “batch-type” process involves loading parts into a large furnace and closing the doors. After a vacuum is created by removing the air, the furnace is heated to the brazing temperature. When the brazing process is complete, the parts are allowed to cool and then removed. New parts are loaded, and the next batch is brazed.

Companies have traditionally used the batch process when brazing base metals that are especially sensitive to oxidation. Oxides on the metal surface will not allow the brazing filler metals to bond with the base metal, so the vacuum created in the oven prevents any oxidation. Unfortunately, the process of loading, evacuation, heating, cooling and unloading is relatively slow and unsuitable for maintaining high-volume production. 

Continuous belt furnaces offer consistency and control throughout the brazing process

Basic Diagram of a Controlled Atmosphere Furnace Brazing line.

Basic Diagram of a Controlled Atmosphere Furnace Brazing line.

By comparison, the continuous belt furnace is open-ended with a long metallic-mesh belt that moves continuously through the heating chamber and cooling zones to the unloading area, returning to the loading area where more parts can be added and brazed. The belt’s speed can be adjusted to carry parts through the furnace at the optimum speed for their requirements. This continuous, non-stop flow of product into and out of the chamber dramatically increases the throughput.

Continuous belt furnaces do not operate in a vacuum. Instead, they are fed non-reactive gases to replace the oxygen and prevent oxidation of the heated parts. In other words, the atmosphere is carefully controlled rather than evacuated. These continuous belt-fed furnaces are efficient and effective, offering a less expensive option for any materials that can be brazed outside of a vacuum.

Determining which inert atmosphere is suitable for a brazing project

An exothermic hydrogen atmosphere reduces surface oxides, particularly on mild or low-carbon steel. It comprises small quantities of hydrogen (H2) and carbon monoxide (CO) and is the most commonly used inert gas in controlled atmosphere brazing. Exothermic hydrogen improves the wetting properties of the base material, resulting in a better flow of the filler material and a lower potential for soot.

Dissociated ammonia is a mixture of hydrogen and nitrogen typically created by the thermal cracking of ammonia in a gas generator. It is especially suited for brazing stainless steel or other nickel alloys. 

Why work with Automatic Machine Products?

Automatic Machine Products can be a one-stop-shop for your next project. We can produce precision machined parts, braze and anneal them if needed, and provide the assembly work, saving your company those internal labor costs and the extra handling expenses.

Starting with our design staff transforming your ideas into reality, we will employ state-of-the-art machine tools with up to 11-axis capabilities to manufacture your parts to your requirements within your time frame. If your parts need secondary machining operations, we can handle that, too.  

Making the components at AMP gives us first-hand knowledge of their design and total control of their quality. Because of that, any brazing and assembly operations will go much more smoothly. 

Of course, we can also modify your supplied parts to ensure a high-quality brazed part with continuous contact between components and an assembly that fits together perfectly. We are proficient at complex assemblies consisting of multiple materials in a single brazed assembly.

AMP’s brazing lines utilize fully automated atmosphere generators that are computer monitored to certify continuous gas quality. A refrigerated gas drying system ensures consistency and repeatability, while a solvent cleaning system safeguards against oxidation.

EXOFLex Exothermic gas generator

The ExoFlex Exothermic gas generator at Automatic Machine Products

One of two inert atmospheres -exothermic or dissociated ammonia-help to substantially reduce or eliminate oxidation, soot, scaling, and other common brazing defects during the brazing process. 

Keep in mind that we offer ISO 9001-2015 quality assurance on our precision machining services, and we test our brazing (including destructive testing) for strength and leak integrity. We use mass spectrometers that automatically detect even the smallest of leaks.

Because our brazing furnaces are running daily for our production needs, our lead times are usually better than most others.

Trust your furnace brazing, precision machining, heat treating, and assembly requirements to Automatic Machine Products. Contact or call us at 508-822-4226 for more information and receive a free sample for your next brazing project.


Secrets of a Successful Furnace Brazing Process

Secrets of a Successful Furnace Brazing Process

brazing furnace

Steel parts going in to brazing furnace

What is the difference between Soldering, Brazing, and welding?

Welding, in general terms, refers to the process of creating a metallurgical bond between two components by way of using high energy to melt the base components (and sometimes a filler material), forming a mixed alloy of the two base parts.

Soldering is the process of joining two components by way of melting a filler material to act as a “glue” between the parts to be joined. The “glue” is another metallic compound that has a lower melting point than the metals to be joined. At the precise temperature just above the melting point of the filler material and below that of the base materials, the filler material will flow into the voids between the carefully positioned base parts by way of a process called capillary action. When the joined assembly is removed from the heat, the filler material will “freeze” and solidify into a durable, airtight joint.

Similar to a soldering process, brazing takes place at higher temperatures, typically over 840°F in order to create a joint with more strength using stronger filler materials. Welding specifically refers to a process where the temperatures are even higher, melting and alloying the base parts together with the filler material.

Brazing, like welding and soldering, can be accomplished via handheld or fixed torch in the open air. However, in order to achieve the best possible brazed joint you need to remove as much oxygen as possible. This is where furnace brazing comes into play. Brazing furnaces displace the oxygen surrounding the work environment to allow for the ideal brazing conditions. Read more

Residential lead-free water components

What to know to find a quality lead-free parts manufacturer

What to know to find a quality lead-free parts manufacturer

Learn to look for suppliers specializing in lead-free metal products

Finding the right manufacturer for quality lead-free parts can be a challenge. It starts by assessing the quality of the part production. Lead makes a metal easier to work with, so switching to newer, lead-free alloys requires specialized skills.

A parts manufacturer must first understand how to work with the more unforgiving lead-free, or low-lead, material, and then know how to use innovative approaches to adapt the manufacturing process.

It’s like knowing how to build a standard car engine in steel – versus having the experience to create a performance engine in high-grade aluminum. You’ve got to be an expert in the material, and know your craft.

For businesses that need to find quality lead-free machined parts for potable water systems, sourcing the best supplier is essential. The goal is to find manufacturers who use careful production strategies – designed just for lead-free metals – and who can supply the highest quality parts, at competitive prices.

So, what do you look for in a lead-free products supplier?

Article Overview

In this article, you will learn answers to:

    • What exactly is a lead-free, or low-lead, metal alloy?
    • What’s involved in making quality lead-free plumbing components?
    • Why, and when, did lead-free metal become required in potable water systems?

Finally, get a Quick List of the information you need to know to search for, and source, a quality lead-free and EcoBrass® parts supplier. 

(ECO BRASS is a registered trademark of Mitsubishi-Shindoh Co, Ltd. –

Read more

Automatic Machine Products announces a new addition to its CNC department

AMP announces the acquisition of a new Eurotech 545 SL-Y mill/turn center.

The high-speed universal turn/mill center with 20 HP spindle, Fanuc 31iT, 12-station turret, barfeed interface, C-axis, rigid tapping and programmable sub-spindle, 5-hp live tooling, Y-axis was acquired to help reduce backlog in the CNC department.

The addition of this machine will greatly reduce congestion during a period of steady growth for AMPs precision machined parts business, thereby reducing order turnaround significantly.

Eurotech 545 SL-Y at Automatic Machine Products

Eurotech 545SL-Y mill/turn

Contact AMP at for your critical precision machined component needs.


Trusted precision parts supplier helps manufacturer overcome a late production challenge.

When a manufacturer’s complex parts proved too challenging for an overseas supplier, a late-stage design change was required.

AMP was selected as the trusted partner to provide the needed capability and responsiveness to create the critical parts within weeks.

The specialized and complex stainless- steel valve balls – parts for a thermostatic valve in a digital water mixing system – had to be redesigned and machined to tight… Read More

Brazing Services – A low cost alternative

Automatic Machine Products now offers furnace brazing services for companies and industries needing metal to metal brazing. AMP has two continuous belt-fed brazing furnaces…one is exothermic and the other dissociated ammonia, to handle just about any brazing you may require. Our brazing can be a low-cost alternative to the more pricey brazing services and offers a fast turnaround time on most projects. Contact us by email or phone to discuss your brazing needs. Automatic Machine Products, we’re your first stop for brazing services, shutoff and service valves, precision machined components, and more.