Rochester Magnet supplies magnetic assemblies that combine ceramic magnets, alnico magnets, or neodymium magnets with steel armatures to multiply holding strength by up to 32 times. Standard sizes are available for quick shipping, with custom configurations built to your specifications.
A cylindrical ceramic or neodymium magnet housed in a steel cup, with a center hole for mounting a handle, hook, bolt, or post. Round base assemblies provide high holding power in a compact footprint. Multiple standard sizes are in stock.
A ceramic or neodymium magnet set into a steel channel, creating a rectangular mounting surface with holes for fasteners. Channel magnets are widely used for tool holders, knife racks, sign mounts, and cable supports. Available in multiple grades and dimensions.
A ceramic magnet positioned between two steel plates. This configuration produces the highest strength increase of any assembly type, multiplying pull force up to 32 times. Sandwich assemblies are used in latches, sign holders, license plate mounts, and industrial fixtures. Available in black powder coat or vinyl coat finishes.
Cylindrical ceramic holding assemblies engineered to resist demagnetization from vibration and electrical fields. Designed for press-fit installation in welding machines and other equipment that generates strong demagnetizing forces.
A magnet enclosed in a non-magnetic sheath that prevents flux loss when the assembly is inserted directly into steel tools, dies, or fixtures. Shielded magnets focus holding force in a controlled area and are available in a range of diameters and lengths.
Simply complete and submit the online form below and we’ll review your specs and contact you with any questions.
A magnetic assembly is a component that pairs one or more permanent magnets with ferrous metal parts, typically steel, to concentrate magnetic flux and increase holding strength. The steel component, called an armature, takes the form of a cup, channel, backing plate, or housing depending on the assembly design.
Without an armature, a bare magnet projects its magnetic field in all directions, and much of that energy is wasted. When steel is placed on the non-working side of the magnet, it redirects flux toward the contact surface, concentrating the field where it’s needed. This results in a significant gain in pull force from the same magnet. In some configurations, a steel armature can increase the effective holding strength of a ceramic magnet by as much as 32 times.
This principle makes magnetic assemblies a cost-effective approach to achieving high holding force. Rather than upgrading to a larger or more expensive magnet material, engineers can use an assembly design that amplifies the output of an affordable ceramic or alnico magnet.
Both ceramic magnets and alnico magnets serve as the foundation for magnetic assemblies, but they bring different strengths to the table.
Ceramic magnets are made from sintered iron oxide combined with barium or strontium. They are the most cost-effective permanent magnet material available and offer strong resistance to corrosion and demagnetization. Ceramic magnets perform well at temperatures up to approximately 480°F (250°C), making them suitable for many industrial environments.
Their lower raw magnetic energy compared to rare earth materials is offset by their affordability, which makes them ideal for use in assemblies where the steel armature compensates for the difference. Rochester Magnet stocks ceramic magnets in blocks, discs, and rings, and uses them extensively in round base, channel, sandwich, and holding assemblies.
When to choose ceramic: Cost is a primary concern, operating temperatures stay below 480°F, and high corrosion resistance is needed without additional coatings.
Alnico magnets are alloys of aluminum, nickel, and cobalt (with iron as the base). They are the best permanent magnet material for high-temperature applications, retaining approximately 85% of their room-temperature magnetization at temperatures up to 1,000°F (540°C). They also resist corrosion naturally and do not require coatings or plating.
Alnico magnets are manufactured by casting or sintering. Cast alnico can be formed into complex shapes, while sintered alnico provides tighter dimensional tolerances and greater structural strength. Common grades include Alnico 2, 4, 5, 5-7, and 8, each offering a different balance of magnetic energy and resistance to demagnetization.
The main tradeoff is that alnico magnets have lower coercivity than ceramic or rare earth magnets, which means they can be partially demagnetized if exposed to opposing magnetic fields or handled carelessly after magnetization.
When to choose alnico: The application involves sustained temperatures above 480°F, requires machinability to tight tolerances, or demands a complex custom shape that can be achieved through casting.
Not sure which material fits your application? Contact our team for guidance.
The performance gain from a magnetic assembly depends on the armature design and how it interacts with the magnet. Here’s how each type concentrates flux:
Magnetic assemblies are used wherever a reliable holding, mounting, or positioning force is needed without permanent fasteners or adhesives.
On the factory floor, magnetic assemblies serve as work holders on welding tables, fixture components for jigs and tooling, and positioning aids for sheet metal handling. Ceramic holding assemblies are particularly valued in welding environments because they resist demagnetization from the electrical fields generated during the welding process.
Sign and banner mounts, channel letter guides, and point-of-sale display components all rely on magnetic assemblies for quick attachment and repositioning. Channel and sandwich assemblies with mounting holes make it simple to attach signage to metal structures without drilling into the display surface.
Alnico magnets and ceramic magnets are found in automotive sensors, DC motors, and electronic systems. Assemblies built with alnico handle the elevated temperatures common in engine compartments and exhaust-adjacent locations.
Magnetic hooks, hangers, and shelf-mount assemblies allow retailers to reconfigure product displays without tools. Round base magnets with threaded posts are commonly used for hanging signage from metal ceiling grids.
Tool holders, knife racks, and equipment latches built from channel and sandwich magnetic assemblies offer strong, repeatable hold with simple installation. Shielded magnets embedded in steel dies and fixtures supply localized holding force without interfering with the surrounding tool structure.
Selecting the right assembly starts with understanding four variables:
Need help specifying the right assembly? Contact our magnet specialists or request a quote with your application details.
Under normal operating conditions and within rated temperature limits, the magnets in an assembly will retain their strength indefinitely. The most common causes of performance loss are physical damage to the magnet, sustained exposure to temperatures above the rated maximum, and prolonged exposure to strong demagnetizing fields (for alnico, which has lower coercivity). Ceramic holding assemblies are specifically designed to resist demagnetization in electrically active environments.
Yes. We manufacture custom magnetic assemblies based on your drawings and performance requirements. Custom options include specific magnet materials, grades, dimensions, armature shapes, finishes, and mounting features. Whether you need a single prototype or a production run of thousands, our team will quote lead times and pricing for your project.
Yes. Rochester Magnet manufactures larger assemblies using multiple ceramic magnets combined within a single steel housing or channel. This approach lets you scale pull force without switching to a more expensive magnet material. Contact us with your target pull force and space constraints, and we’ll design a configuration that meets the requirement.
A detailed look at material quality and longevity when comparing standard industrial magnets to budget-friendly alternatives.
Learn the differences between Pull Force and Gauss ratings, and how to properly test magnetic strength for your application.
Explore how custom die-cut shapes can increase the visibility and perceived value of your promotional magnetic products.