Custom Magnet Manufacturing
Bunting-DuBois is the only North American manufacturer of compression bonded, injection molded and hybrid custom magnets. In addition, we are a provider of sintered neodymium magnets and magnetic assemblies. Our exclusive NeoBlend™ neodymium magnets are custom magnets that can be designed to any size, shape or strength thanks to a complete range of powder compaction and injection molded presses from 4-ton to 200-ton. The design considerations include temperature, vibration, cost, oxidation, electrical conductivity and more. We also have expertise in Alnico, Ferrite and Samarium Cobalt magnets and numerous production routes, including sintering, extrusion and calendaring, Our plant is ISO 9001:2015 certified, ITAR registered, and has the team in place to build two hundred to two million pieces or more per month.
Bunting is a one-stop shop specializing in magnetic assemblies. With our extensive knowledge of CNC machining, magnet fabrication and final assembly capabilities, we can meet any magnetic assembly need no matter the complexity. We utilize the latest and leanest technologies applied to assembly processes such as bonding, fastening and potting. Assemblies can be welded, sleeved or encapsulated. Our final processes (post assembly) include final grind, balancing and filed mapping allowing Bunting-DuBois to deliver a quality driven and precise magnet assembly no matter the complexity.
- Precision Machining
- Packaging, Stocking and Traceability
- Validation and Testing
- Rapid Prototypes
- Any Quantity – long or short run
- Quick Shipment within the U.S. (Pennsylvania-based manufacturing)
We provide complete engineering, design and consulting services. We collaborate with your team to create well-designed, flawlessly manufactured permanent magnets or a complete magnetic assembly specific to your need and application. We are able to provide rapid prototypes and quick distribution of the final product no matter the complexity of the project
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Magnet Types & Processes
Bunting-DuBois specializes in manufacturing magnets and technical assemblies using a variety of processes. The most significant feature of our bonded magnet processes is our ability to precisely target the magnetic performance and utilize net-shaping techniques, allowing us to achieve even the most complicated shapes. We give you exactly what you need to achieve the level of performance that is needed for your specific application. We offer a number of different performance levels, but in some cases a precise blend is created to give you the most effective solution.
Processes, Performance & Shaping
Based on techniques used in ceramics, powder metal and pharmaceuticals, Compression Molded requires the lowest level of non-magnetic binder, thus producing the highest magnetic performance in bonded magnets. The use of compression bonded is almost exclusively restricted to rare earth alloy products such as Neodymium Iron Boron (NdFeB).
The shaping limitations of compression molding are found in the need to eject a part of the tool. The most common shapes are 2-D rings, but compression molded is also available in disks, blocks and segments. The binders used in compression molding are typically epoxy resins, which have good dimensional stability and resistance to chemicals. Some are able to withstand temperatures in excess of 250°C.
The maximum energy product achievable is typically 12 MGOe for Isotropic product, while anisotropic (aligned with a field during molding) grades of samarium high cobalt give even higher performance and enhanced temperature stability.
Injection Molded is ideal when additional precision or complexity of shape is required. It is also used where insert or over-molding is beneficial. This technique is used for high volume production because of the relatively high tooling and equipment cost.
Binders include a range of nylons, polyphenylene sulfides and other polymers for operating temperatures excess of 180°C. The loading of magnetic powder that can be incorporated is lower than compression molding, resulting in lowered magnetic properties.
For ferrite powders, the upper limit is approximately 2MGOe, while isotropic NdFeB is up to 6MGOe and bonded isotropic NdFeB is up to 12MGOe.
Injection Molded can offer significant savings and improvements in precision for applications where magnet components are molded directly on to shafts or where additional assembly operations can be removed from a process.