he business of manufacturing and moving metals is challenging and often dangerous. Industrial magnets can help improve operations’ efficiency and safety by streamlining processes, protecting workers and preventing damage to materials.
Walker Magnetics, Windsor, Connecticut, has been designing and manufacturing industrial magnetic products for over 120 years and provides custom solutions to lifting, material handling, workholding and separation applications for the metals supply chain from mills to service centers, foundries to fabricators and everything in between.
“Customers should consider looking for a provider that can be a one-stop shop for a complete magnet system,” suggests Byron Rosengarten, product line manager for Walker’s Heavy Lift products. “Walker Magnetics supplies not only magnets but also spreader beams, magnet controls, battery back-up systems, field service support and magnet repair for any future needs. This is the best way to ensure the systems function properly together.”
Walker uses three main types of magnets in its products—electromagnets, permanent magnets and electro-permanent magnets—and its designs take advantage of each style’s magnetic strengths.
“The type of magnets a customer needs will be determined by the application,” says Rosengarten, noting that a common misconception is that heavier material is more difficult to lift with magnets.
“In reality, thinner material, such as plates below 1/8-inch thick, requires advanced magnet system design consideration. Thin plates offer less material for magnetic flux to saturate, meaning the magnets are able to pick up less weight on thinner material,” he explains.
The type of magnets a customer needs will be determined by the application. 
Different alloys also have different magnetic properties, which means systems designed to be installed at metal distributors have their own special set of requirements.
Grade A36 steel is the most common material being lifted and is the “baseline” for magnetic lifting, says Rosengarten, but alloys that have larger magnetic declination rates require either more or stronger magnets. For an operation handling different sizes and alloys on a daily basis, “we assume worst-case scenario, which would be lifting the alloy with the greatest magnetic declination rate and lifting the longest, thinnest material and/or the heaviest lift the customer wishes to complete.”
Customizing the system is the most cost-effective way to create a magnet lifting system. Without customization, he says, “you will likely be adding unnecessary weight to the system or oversizing magnets when it’s not necessary.”
As for safety, magnets give operators greater control over the load, compared with pulleys, chains or slings, and there is little lifting-capability degradation of the device over long periods of time.
“We design our systems to comply with the ASME B30.20 standard for below-the-hook lifting devices,” says Rosengarten. “This includes a safety factor of at least 2:1 for our magnet systems. When you use magnets, you don’t risk someone getting injured while attaching chains to a load. The only person required is the crane operator, which means there’s no need to have anyone in harm’s way.
Walker built a system for a plate mill that “now uses magnets in their shipping bay to load railcars, and the system only requires the crane operator instead of multiple people to attach the load via chains,” according to Rosengarten.
Multiple plates can now be safely lifted in a single load, transported and released in the desired location. “It’s also an immediate lift for the crane operator—instead of waiting for chains to be connected to the plates.”
“The electrical readings should be compared to the name plate located on the magnet,” he says. “Significant differences in electrical properties can indicate a coil issue. Early detection of electrical and mechanical issues will ensure the safety of the lifting device and potentially reduce the cost of ownership.”