May/June 1991
Collecting and applying the latest knowledge in magnetics in as many ways as its customers want is the specialty of this ambitious company.
By Jeff Borsecnik
Jeff Borsecnik is assistant editor of Scrap Processing and Recycling.
"The magnet is just a tool. What we do really well is figure out how best to use it," says Dick Longo, a vice president of O.S. Walker Co. (Worcester, Mass.).
Innovative application of magnetics, in fact, is the specialty of the entire Walker Magnetics Group, O.S. Walker's parent company, which oversees more than a dozen firms around the world that develop, manufacture, and service lifting magnets, conveying and separation systems, scientific instruments, magnetic chucks, and a variety of other products.
Building a Scrap Magnet
The most prominent of these products in the scrap industry is the lifting magnet, which is the focus of three of the group's companies. O.S. Walker Co., Walker National Magnetics Ltd. (Burlington, Ontario), and Walker National Inc. (Columbus, Ohio) work closely together to manufacture lifting magnets and related material-handling products for the Walker Magnetics Group's North American market. The two "Nationals" also participate to a lesser extent in another area of increasing importance to the group: separation systems. (They do not participate in O.S. Walker Co.'s business in work-holding products.)
Customer demands and limitations—such as maximum magnet weight a certain crane can handle, the shape and size of a specific container the magnet will load and unload, and different sizes and materials available for magnets--dictate that most magnets be built to order. Walker is proud of the sophisticated computer-aided design system it has created to help develop lifting magnets. The system allows engineers to easily input any limiting variable, such as maximum acceptable diameter or weight, and quickly see the result of that constraint on a proposed design.
Welded-case or "fabricated" magnets are much easier to customize than cast-body magnets, says Mike Kozminski, regional sales manager for the lifting division, so the company sells many more of the former than the latter to scrap processors. The side of a fabricated magnet is a large rolled ring of steel with a welded seam. The core is a heavy cylindrical section of steel bar, about 12 to 18 inches in diameter. These two parts act as the poles of the magnet.
To assemble the magnet, Walker machines the core, attaches it to a circular top plate, and prepares its bottom plate. These steps are typically handled while waiting for the ordered electromagnetic conductor to arrive, if not in stock. The conductor, which is the heart of an electromagnet, is the most expensive component and typically takes the longest to arrive, says John W. Bernard, O.S. Walker vice president of operations.
The conductor materials range in thickness from approximately 0.008 to 0.050 inches, come in various widths—usually several inches—and are made of aluminum or copper. According to company officials, there is a strong "copper is better" myth among magnet buyers, but Walker encourages use of aluminum as the conductor in scrap magnet coils, pointing to its savings in cost and weight. Although copper is a better conductor—clearly a plus—it’s not a better conductor per pound, say Walker officials. The experts do note, however, that copper coils typically last longer than aluminum.
When the conductor arrives, it is carefully wound around the core, along with an insulation wrapped within the coil. Most Walker scrap magnets have two separate conductor coils—a compromise between having one, which is too weak for most scrap applications, and having three or more, which subjects the magnet to overheating.
The prepared coils are separated from each other and the case by a fiberglass insulation product and are then compressed under a large press, welded in place, and surrounded with potting compound. This self-polymerizing substance flows into the air cavities around the coils and solidifies, preventing collection of moisture and acting as a shock absorber, company officials say. The bottom plate is attached and sealed, and the magnet is then tested, painted, and shipped to customers by truck.
All three companies repair lifting magnets in addition to manufacturing new products, with O.S. Walker having a greater share of the new-product work because it is the design and engineering headquarters for the three firms.
A Big Small Company
The Walker Magnetics Group's corporate headquarters is a tidy, yellow wood-frame house across the street from O.S. Walker Co. This homey atmosphere is a contrast to the group's size and scope.
The firm was founded by Oakley Smith Walker shortly after he patented the revolutionary electromagnetic holding chuck—which is on display in the Smithsonian Museum in Washington, D.C.—in 1896. Walker, who had worked for Thomas Edison, also invented other products, but his chucks were to become the bread and butter of his company. Today, the Walker companies are the dominant supplier of magnetic chucks in the United States, holding about 80 percent of U.S. business in magnetic work-holding tools, according to the company.
By the 1950s, Walker's company had been sold to a group of private investors and ended up in the hands of an inventor and international businessman, John Engelsted, who remains at the helm of Walker Magnetics Group as chairman of the board. Engelsted continued Walker innovation, patenting the first ceramic-type, permanent-magnet chuck. He also introduced a philosophy of growth through acquisition, a concept that continues today.
Through the years, Walker Magnetics Group has purchased a variety of companies—both domestically and abroad—involved in the manufacture of magnetic application products, including several small firms with expertise in scientific magnetic instruments. This emphasis was to result in Walker Scientific, a company that produces technical laboratory equipment such as meters to measure magnetic attributes and exotic laboratory magnetic coils. Walker Scientific, which shares its office space with O.S. Walker, also acts as a research and development arm for the entire group, figuring out how to apply new materials and magnetic technologies to Walker products. Another company with a scientific bent, Walker Sonix, was formed from the acquisition of two English companies with expertise in nondestructive testing using magnetic instrumentation.
Although the Walker Magnetics Group has a healthy appetite for acquisition, purchasing both competitors and manufacturers whose products were new to Walker 's line, it now keeps a focus on industrial magnetics. For a number of years, however, the company went through a period of rapidly acquiring manufacturing companies in a variety of fields, including textile machines and automotive hoists, but many of those companies have since been sold off.
The company has had to develop this expertise in its managers, engineers, and production workers. "You can't go to college and take a course in magnetism," explains Kozminski. "Our knowledge is the result of our experience and experiments with magnets over time." Longo says the group looks for "mechanical engineers who have a feel for electronics and electrical engineers who have a feel for mechanics. ... Someone who is an expert in only one discipline really wouldn't make it here." The company has apparently been able to retain its multidisciplinary experts—many of those working in the Worcester operations can measure their magnetics experience in decades.
Longo notes that selling scrap handling magnets is a very different job when scrap trade is active than when it's down. When prices are down, customers are not in a hurry and will be "very very particular. They will want either something that they just read about or heard is the latest and greatest, or they will want something exactly like they have been using—down to the serial number." On the other hand, he says, when prices make it worthwhile to move as much scrap as possible in a short time, it's a different story. "They say, 'Quick, ship me a magnet.' They don't care what it is, as long as it's near compatible with their electrical system and their crane. They want it, period." To Longo, the toughest part of Walker 's business in industrial magnetics is the quick swings in the business cycles of the industries the group serves.
Stimulus and Response to Innovation
Two forces propelling Walker Magnetics Group are technological advances, such as those prompted by development of new materials, and demands from customers for new or improved products. "We are opportunists," says Longo, explaining that Walker is careful to follow and quick to take advantage of new materials and technologies developments. Nevertheless, he points out, "it does no good for us to invent or develop some new product that does not have a market."
Requests from customers have continually encouraged the group to expand its capabilities and product lines. "As cliched as it sounds, we believe that we solve problems for our customers," Longo says. For example, as an adjunct to manufacturing components for a magnetic conveying system that moves cans at a food processing facility, the customer asked the group for technical help in handling a neighboring line of glass containers. Then, another firm saw the results and asked the company to develop a system to handle its line of fan belts on an automated system.
Walker targets recycling as the industry it serves that is hungriest for new products. Buyers of Walker scrap magnets are showing interest in materials separation equipment, as are municipalities and other operators of material recovery facilities. Walker has responded to this interest, in part, by developing a new separation system based on the eddy current, a rapidly changing field of alternating polarities. The eddy current repulses metals that enter the field, separating nonferrous metals from nonmetallics in commingled materials.
The group is also marketing other high-tech products, though for more limited markets. Walker Sonix, for instance, has produced and is beginning to sell an ultrasonic bone analyzer designed to help doctors detect osteoporosis, and Walker Scientific is selling a new tool for detecting extra4ow frequency radiation produced by electrical equipment. The group is also developing applications for new, extremely powerful rare earth magnets.
Longo pauses when reporting on other moves for the group, careful not to give away the store. He settles on saying the company remains "acquisition-minded," with a specific interest in manufacture and distribution of electric power sources, a business closely related to its lifting magnets and other products.
The company is also always looking to expand geographically by acquiring operations in the Pacific Rim countries, but has repeatedly been stymied by "inordinately high" real estate costs there. The company has long been active in Europe and clearly is not worried about the coming common market. Walker does have new "things going on right now" in Eastern Europe, Longo notes.
Despite the Walker bent toward growth through acquisition, growth in much of the company's line of business is not vital, says Longo. There is no "growth for the sake of growth," he explains. Except for some specialty markets, the company serves mostly mature industries such as the scrap processing and machine shop industries and, therefore, tries to maintain its own maturity, Longo says. "The primary function is that we be a responsible, mature, profitable company."
Fixing Magnets
Because of the longevity of lifting magnets, the necessity of periodic servicing, and the limited demand for new lifting magnets, repair and rebuilding is a major facet of Walker’s business. The company’s Columbus and Burlington facilities, in fact, spend more time on repair than new magnet manufacturing.
Its long history of manufacturing lifting magnets helps the company succeed in the magnet repair business if for no other reason than that Walker maintains the original blueprints to magnets made as far back as the 1940s. “We now have more drawings, new and old, than any other magnet manufacturer in the world,” Dick Longo claims. Having them on hand can be a big help, particularly when the magnets are older than the workers attending to them.
Most lifting magnets used by scrap processors need service about every three to 10 years, and most can be resuscitated a few times, according to the company. Repair, however, is a trickier job than original manufacture and presents special headaches, says John Bernard. It can mean exotic challenges, he says: “Say a man has used a magnet for 10 years, he’s modified it, he’s welded stuff all over, he’s fixed it once himself, and then he sends it to us.” Bernard clearly prefers managing the new magnet side of the business, but notes that Walker ’s goal is to satisfy its customers. A successful repair usually means a satisfied—and happy—customer because rejuvenating a lifting magnet often costs only about half as much as a new one and can come with the same kind of warranty.•
Collecting and applying the latest knowledge in magnetics in as many ways as its customers want is the specialty of this ambitious company.