September/October 1997
Esco Corp. has made a name for itself by producing metal parts rugged enough to hold up under the roughest use. Here’s a look at how this international company is bringing its know-how in wear parts to the scrap processing industry.
By Eileen Zagone
Eileen Zagone is an associate editor of Scrap.
A stroll through the headquarters of Esco Corp. in Portland, Ore., can make you think you’re in London, Paris, or perhaps the United Nations building in New York City. That’s because Esco’s corridors often ring with a mélange of international accents—a reflection of the company’s worldwide scope.
This truly global business spans the planet, with subsidiaries and manufacturing facilities across North America, distribution and sales offices as dispersed as Germany and Singapore, as well as licensee companies in Chile, South Africa, and Australia, to name a few.
The industries Esco serves are equally diverse, ranging from scrap recycling to logging, from mining to aerospace and nuclear power. Such breadth of business is a legacy from C.F. Swigert, who founded Esco in 1913. Swigert originally built bridges across the Willamette River that bisects Portland, but gradually expanded his operations to service the city’s streetcar system, as well as the region’s burgeoning timber industry. Branching out into the foundry business, Esco (then known as the Electric Steel Foundry) was the first foundry west of the Mississippi River to use an electric-arc furnace, the company says. During World War II, it devoted production to war material, then turned to manufacturing increasingly larger parts for the iron, copper, and coal mining industries.
Despite their diversity, Esco’s customers share a common need—components that can stand up to the harshest conditions, whether in a submarine, hydraulic hammer, or automobile shredder.
In fact, given Esco’s background in creating wear parts for use in mining and other rugged environments, its expansion into the scrap recycling industry seemed natural. After all, the components of processing equipment, particularly shredders, must be able to withstand tremendous stress. So, about 15 years ago the company began to manufacture shredder wear parts, including hammers, grates, liners, and other nonrotating parts. Esco makes most of these parts from manganese steel because of the alloy’s work-hardening characteristics—the more impact and stress this metal takes, the harder it becomes. “It thrives on work,” explains Dave Crum, technical product specialist.
Metallurgical Magic
The longevity of any wear part begins with its metallurgical makeup, of course. So, it’s in the melting pot that Esco’s experience in wear part technology pays off, the company believes. “We consider ourselves to have perhaps the best metallurgy lab in the world,” says Jim Liberator, Esco’s manager of business development. In the Portland office, for instance, one of the six metallurgists on staff even has a Ph.D. in tribology—the study of wear. Spending their days in a clustered group of rooms near the company’s Portland foundry, these metallurgists analyze what it takes to break different alloys and work with the firm’s engineers to develop just the right blend of metals to stand up to particular applications. The firm analyzes metal with spectrometric devices as well as a scanning electron microscope that allows the team to magnify metallic structure up to 300,000 times.
Thus armed with the proper alloy recipe, the next step is to create a melt with particular specifications. Here again, Esco’s experience in creating parts that will perform well under designated conditions plays a crucial role. According to Liberator, Esco starts with scrap metal to create more than 100 different alloys to meet the requirements of individual wear parts. Each of these alloys has a particular range of metallurgical characteristics, he explains. And while the range is narrow already, Esco can tighten the specification even further to produce a melt mix—and resulting part—even more metallurgically specific.
All this is possible because of exacting process controls that assure “mistakes just can’t be made,” Liberator says. While the company is reticent to discuss the specifics of its process controls, Liberator explains that the same process controls are followed to the letter at every Esco plant—all of which, by the way, are ISO 9002-registered—to ensure that parts are exactly the same, no matter where they’re made.
Once the desired metal potion is created and its chemistry verified, Esco may further refine the melt in an argon oxygen decarburization vessel. This additional step helps remove contaminants such as hydrogen, nitrogen, and sulfur from the molten metal—contaminants that may create gas bubbles or other defects in the cast product. This so-called AOD process also increases the toughness, strength, and ductility of high- and low-alloy steels without losing any hardness, the company reports.
Next, the molten metal is poured into a prepared mold. Esco uses any of four different methods to mold the castings, depending on factors such as the final casting’s size, shape, and other requirements. This phase of the operation requires extremely accurate and often complicated patterns. These patterns, made of wood and other materials, are precise models of the final product and are used to make the casting molds. With new patterns in constant demand, Esco helps keep several local patternmakers in business, says Liberator.
Vast quantities of sand are also required. Esco often mixes the sand with clay or other binders and then packs it around the patterns in box-like metal flasks. This forms the mold into which molten metal is poured. Sand is critical not only because it retains its shape when heated, but also because it provides insulation so that the molten metal stays hot and liquid enough to flow evenly into the most intricate castings. Nearly all of the sand used in the operation is reclaimed, Liberator notes. In fact, the foundry has an entire system dedicated to liberating reusable sand from grains that are too fine or from stubborn chunks of sand and binders.
After pouring, the sand and molten metal-filled flasks are “cooled” for at least several hours until the casts are set—although with temperatures in the casts still surpassing 1,000oF, it’s hard to think of them as cooled. Once set, the manganese steel casts are moved to the heat-treating area of the operation. Here, the parts are held at a constant temperature to dissolve the ferromanganese carbides. Then the parts are plunged into a bath to prevent the carbides from reforming. The result is a nonmagnetic casting of austenitic manganese steel.
All of Esco’s alloyed steels go through some form of heat treatment, Liberator notes. Indeed, this stage of production is considered critical to the extra life of Esco’s wear products. And while heat treatment is hardly unique to Esco, the company’s exacting process controls produce a uniform, tough metal that makes superior parts, he maintains.
Following heat treatment, each part is hand finished to remove any rough edges and make sure it’s sized to meet the customer’s specifications. The finishing stage is a delicate one because heat-treated metal surfaces tend to harden and become difficult to machine. Esco overcomes this obstacle by using special carbide tooling equipment and different machining techniques to work the tough metal until it meets specifications. To pass the final Esco quality test, some parts are also examined through a sort of three-dimensional X-ray process that shows any cracks, air holes, or other imperfections that could affect the performance and longevity of the product.
Wear parts, by definition, don’t last forever. So, what Esco boasts about is its parts’ long life, Liberator says. And though some Esco parts may seem expensive, they cost less in the long run because they don’t have to be replaced as often and don’t require as much scheduled equipment downtime as other wear parts, he claims.
Building Wear-Resistant Partnerships
Here’s an example of just how confident Esco is in the quality of its products. A shredder operator called once complaining that a particular part—supposedly manufactured by Esco—had broken. Liberator couldn’t believe it and so jumped on a plane to check out the situation. As he suspected, the broken component wasn’t an Esco casting after all—but the new part that replaced the broken one certainly was.
Such a story demonstrates not only Esco’s faith in its products, but also the company’s commitment to customers, Liberator says. In the scrap recycling industry, he adds, Esco has been making products for more than a decade and cultivates “long-term partnerships” with shredder operations.
Of course, customer service starts well before any of the castings are poured. As Dave Crum explains, the parts designed for one shredder may seem quite similar to the parts meant for another model, but there’s actually a lot of custom engineering and product development involved in each job.
As anyone familiar with shredding knows, the people who understand the equipment best are the ones who work with it day in and day out. So, Crum and his staff of engineers like to work closely with shredder operators to build the proverbial better mousetrap—subtly tweaking measurements, angles, and sizes of a shredder’s internal organs to come up with just the right design to suit a particular operation.
The company is even willing to investigate new ideas that Esco’s engineers hatch with customers—in some cases going so far as to create experimental patterns and castings that require considerable outlays of money and manpower, Crum and Liberator say. But it’s all in the name of producing wear parts that will work better and longer under the harsh conditions of a car shredder.
While equipment parts for the scrap shredding industry currently make up only a small percentage of Esco’s overall business, company executives hope for steady growth in the scrap niche, with North American sales of its shredder wear parts handled primarily by Sunbelt Technologies Inc. (Dallas). And lest anyone think that Esco sees recycling products as just an incidental sideline to its larger interests in mining and aerospace, the company points to its multimillion-dollar investments in plants that produce recycling wear parts, as well as the long-term partnerships it’s established with several large shredding operations in the United States and Europe.
As for diversification into other products for the scrap processing industry, Esco remains guarded. The company’s focus, executives say, is on expanding the number of automobile shredders using its wear parts. But who knows—scrap recycling is a big industry and there are plenty of unexplored markets for Esco to cast about in. •
Esco Corp. has made a name for itself by producing metal parts rugged enough to hold up under the roughest use. Here’s a look at how this international company is bringing its know-how in wear parts to the scrap processing industry.