Columbia Steel Casting Co.

By Jeff Borsecnik

Jeff Borsecnik is assistant editor of Scrap Processing and Recycling.


The 1,000-foot-long main foundry building at Columbia Steel Casting Co. (Portland, Ore.) is everything you'd probably expect in a metal-melting operation--rows of hanging lights that converge in the distance, tongues of flame, puffs of smoke, and a dusting of burnt-looking casting sand. Other corners of the company's 90-plus-acre property, however, reveal a surprisingly varied operation: Besides a huge machine shop, there is a brightly lit pattern shop that smells like sawdust, as well as silent, sterile warehouses packed with more than 15,000 patterns for everything from shredder roof covers to cheeks for giant drag line buckets.

In other words, Columbia isn't your run-of-the-mill foundry. Not only does it cast industrial wear parts for use in automobile shredders and other heavy equipment, but the firm also designs the parts, makes the patterns and molds, and finishes the castings-earning it a designation as one of the last remaining foundries vertically integrated at a single location. It's also one of the few U.S. foundries of any kind capable of casting very large items or exceptionally difficult ones, such as tooth gears, a skill Chief Engineer Bruce C. Johnson refers to as "an almost-lost art."

Booming With Portland

The art traces its roots to the turn of the century, when Portland boomed as the supply center for the growing Northwest region, and Columbia Steel Casting, founded as Columbia Engineering Works in 190 1, boomed along with it, manufacturing steel products for gold mining, logging, irrigation, and railroads. Business continued to thrive through the early 1900s, attracting several ownership changes (as well as name changes) before ending up in the hands of Hobart M. Bird Sr., a foundry employee who climbed through the ranks. (Bird's son, Hobart M. Bird Jr., eventually succeeded his father and remains at the company's helm.)

Then came the Depression, and Columbia, like most of the industries it served, was forced to make major cutbacks. Still, demand continued for gold mining products, the foundry continued to produce gold mining innovations such as replaceable lips for dredging buckets, and, consequently, this sector grew to account for about 80 percent of Columbia's business during the period. New Deal construction programs eventually also provided a boost by increasing demand for castings for the aggregate industry.

World War 11 changed everything. Gold mining was suspended, and military needs strained Columbia's abilities, beginning with its first war-related order for more than 200 4,000-pound castings for Liberty ships. The company had never made anything so big-and that was just for starters. In fact, the war effort eventually saw the foundry cast hundreds of steel ship's propellers-some measuring 20 feet in diameter and weighing more than 20,000 pounds-and compelled the firm to increase its melting capacity. With this new business, Columbia increased its technical capabilities as well, developing methods to speed the manufacture of large castings, thereby winning the company recognition for its war efforts.

The abrupt deceleration of production with the end of the war came as a shock to the foundry, which was also hit by a flood and a major fire in the years that followed. But the firm landed back on its feet, thanks largely to its expanding abilities and the growing sophistication of its products. For example, Columbia, which had served mostly as a "jobber" foundry, producing only castings from supplied patterns, added design, pattern-making, and finishing abilities in the 1950s-a move that company officials see as key to its position in the marketplace today.

Adding a Shredder Line

In the 1970s, the firm evolved further, diversifying its product line beyond aggregates and mining to the automobile shredder market, where Columbia has built a parts business emphasizing custom work. This is particularly true with new clients, who frequently look to the foundry to help solve their problems or improve their productivity, Columbia officials say. The company's product engineers typically visit the shredding operation, measuring the machine, examining worn parts, and collecting information and ideas from the operator, before heading home to design solutions. "It's something we expect to do for everybody that has a shredder," says Berle Stonebrink, product engineer. "But it makes our selling prices a little higher since we're the only company that really does it."

As a result, he says, few customers buy all their shredder wear parts from Columbia, but he guesstimates that 80 percent of North American shredder operations buy at least some of their wear parts from the company. Thus, Stonebrink points out, shredder operators will pay for Columbia's expertise--when longer-lasting parts and less down time are priorities. "If we can't help them reduce their operating costs, then we're not in business."

Since adding shredder parts to its line, the company has subsequently also ventured into the cement, coal crushing, power plant, brick, coal gasification, and solid waste industries, and a small catalog of parts dating back just 18 years ago has since been replaced by product listings that fill five ring-binders. Of course, this diversification has also meant expansion of staff-from three or four product engineers in the early 1970s to 22 today-and steady investment in the physical plant. "The place has grown almost continuously for the last 20 years or so," says Johnson. "In the 1970s, I used to call it the million-dollar-a-month club--that's what we were spending on the place in new melting equipment and molding lines--and it continues today."

Wood Shop to Sandbox

Columbia manufactures its range of products through a mix of modem technology and old-fashioned craft, with much of the craftsmanship coming out of its vast pattern shop--"a wood-working hobbyist's paradise," as Johnson calls it. Most of the patterns are made of wood--easily carved Oregon sugar pine, exotic Honduras mahogany, abrasion-resistant oak, high-quality "Baltic-birch" Russian plywood, and others--that is not so much cut and drilled as machined like metal on sophisticated equipment such as a table saw capable of cutting within a tolerance of thousandths of an inch. Plastics and metals are also used for patterns, especially for parts that are manufactured at higher production rates that lead to considerable abrasion on the patterns from casting sand. Plastic, which can be most-accurately formed, is also used for patterns that must be k particularly precise.

Pattern-making is a major exception to the rule that casting is generally less labor-intensive than fabricating, and that certainly holds true at Columbia. The company's patterns can be very complicated, so its pattern-makers must be highly skilled--"the finest woodworkers you'll ever see," Johnson calls them. And these artisans bear substantial responsibility for the final product. "To a large degree, we hold the pattern-maker accountable here," he says. "After a guy makes a pattern, we send him across the street to watch them make the mold and later he has to be around when the first castings come out. If the castings don't come out like the drawing, then he's the one that fixes the problem."

Sand molds are used for nearly all of Columbia's castings, thanks to sand's formability and the fact that it retains its shape when heated. But sand has its weaknesses, Johnson points out: "Molding sand-clay-bonded sand as we use-is very much like reinforced concrete," he says. "It can handle compression, but it can't handle tension." So the foundry reinforces the sand molds as if they were made of concrete, with reinforcing steel.

Sand is at the heart of Columbia's business. In fact, the company generally moves more than 4 tons of sand for every ton of metal it melts, according to Johnson. "I always claim we are really in the sand business," he says, noting the foundry has one metallurgical lab and three sand labs.

A variety of techniques are used at the foundry to pack sand (along with small, precisely controlled amounts of western bentonite clay, corn sugar, and corn flour, which bind and cushion the sand particles, plus moisture) around patterns in metal boxes called flasks to produce molds. Like pattern-making, molding--especially large-part molding--is a highly skilled craft.

Columbia uses its sand molds only once because their binders break down under the heat of casting, but the company recycles the sand using a scrubber that blows it against metal targets, breaking the binder coating off the grains so that these and other fine particles can then be removed with dust collectors. The process enables the foundry to reclaim about 98 percent of the sand, thus limiting its sand purchases and disposal costs. And in the future, the company could cut its 2-percent sand loss in half through a more sophisticated system called a thermal sand reclaimer that it is considering installing.

Making Metals

Once the molds are completed, they're sent on to be filled. For shredder parts, this means casting of manganese steel or low-alloy steel, depending on the product and its need for resilience vs. resistance to abrasion--or "toughness" vs. "hardness," as Columbia's engineers put it. Although these key properties are not exactly mutually exclusive, they are opposed to a certain extent since a hard, abrasion-resistant alloy is relatively brittle, limiting its toughness. "We spend our lives trading hardness for toughness around here," says Johnson. "Alloy irons are the hardest, manganese steel is the toughest, and everything else is somewhere in between."

The company casts nearly all of its side liners, roof covers, grates, and most other shredder parts from manganese steel, which "work hardens”--develops a harder surface from use. But some rotor caps and hammers are instead made of high-strength, low-alloy steels, which give up a bit of toughness compared with the manganese steels but offer greater hardness, plus somewhat better performance and a longer life span in certain parts. On the downside, the latter alloys face a slightly increased risk of breakage, Stonebrink notes, explaining the potential consequences: "If a hammer comes apart in a shredder, it's going to break an awful lot of hammers and other parts before the machine is stopped." So where there is an alloy decision to be made, he says, it comes down to a shredder operator's own experiences and preferences.

After an alloy has been melted and refined, the molten metal is dumped from the furnace into a large ladle manipulated by an overhead crane. Workers in heat-reflective clothing then direct the ladle along rows of prepared flasks, tipping it to pour the red-hot liquid through funnels into each box.

The castings are then allowed to cool for four hours or more. Says Johnson: "If we are making one of our 20-ton slugs as a primary liner for a rock crusher, it actually stays in the mold for three days before we feel comfortable enough to remove it." Even then, the casting is still more than 1,400 degrees F, he notes, adding, "sand's a good insulator."

The Finishing Touches

When cool enough to be "broken out” of the molds, the castings go immediately into heat treating, which is at least as important as chemistry in determining alloy characteristics such as hardness and toughness. Manganese steel, for example, must develop what is called an austenitic grain structure, which forms at temperatures above 1,400 degrees F and is only retained if the metal is rapidly cooled. "If you don't heat treat it properly, it's really a very bad material-you wouldn't really want it," says Johnson. After a period of heat treating, the manganese steel parts are immediately dunked into a cooling bath, which, surprisingly, doesn't give off steam when the glowing metal hits it because the pumped water circulates so rapidly that the water temperature rises only slightly.

Other alloys go through different heat treating and cooling cycles that produce different physical characteristics. The high-strength steels, for instance, are "annealed”--heat treated slowly at a low temperature to remove any residual stresses created during casting-followed by long, slow cooling in carefully controlled furnaces.

In another finishing process, Columbia combines welding with heat treating to produce what Johnson calls the "ultimate material" for wear parts--a tough material with a hard surface. In the "Xtend" process, a harder material is welded onto the surface of manganese and other steels under conditions that nullify the usual drawbacks of welding. He explains: "Some people would like you to believe that welding is the greatest process that's ever come along and everything should be fabricated and welded together." The problem is, welding can destroy the surface carefully created during heat treating and it can create subsurface cracks that can later propagate, he says, noting that the Xtend process avoids these drawbacks.

Some castings, especially those that demand very flat surfaces or tight fit, are machined to final tolerances. They may also get a final round of heat treating to increase their surface hardness. Most parts also go through a cleaning process that typically involves removal of extraneous metal such as gates and risers left over from casting or heat treating as well as shot blasting to remove scale.

Finally, Columbia employs an automated measuring system as well as ultrasonic and X-ray testing to double-check the quality of finished castings. Samples of parts cast for the first time are tested to gee if they contain any hidden flaws. Parts produced regularly are periodically sampled to ensure continued quality.

Beating the Odds

The fact that Columbia is in business and can design and manufacture its products at all is noteworthy in itself, considering there was a period during the 1980s when four U.S. foundries were going belly-up a week, according to Johnson. So how did the company come out on the up side? The chief engineer attributes Columbia's survival to a solid financial base built through continued investment in the company and its refusal to participate in. "horrendous" price wars that drove many foundries under-plus a smattering of luck.

Columbia's managers also credit the firm's strength to its vertical integration--which allows it to quickly produce quality custom parts--the teamwork that comes with this vertical integration, and efforts to stay ahead of environmental regulations, which have won awards for the company.

And perhaps there's another reason--pride in being among the last to practice its almost-lost art. "There's really hardly anyone left that can make things as big as we can, do the things we do," says Johnson. Besides, he adds, "The people here really like this industry and its big, noisy, smoky toys." •