Going with the grains: Hamlin Casting is the most productive U.S. foundry that makes money molding melted metal with sand.

• Author: Martin, Edward
• Position: PICTURE THIS

The path to this place of intense heat: and pressure is long. More than 26 centuries ago, the Chinese discovered they could pour molten metal into impressions in moist sand to make tools such as plows. In 1946, Frank Hamlin began using a similar technique--called sand-casting--in an Illinois plant. Much has changed, but the basics are the same. Aluminum still liquefies at 1,221 degrees Fahrenheit and that keeps the doors open at Hainan Casting Corp. in Pilot Mountain. Over the years, CEO Bill Welden says, it has sand-cast more than 60 million pounds of parts for the marine, electrical, trucking, aerospace and other industries, the most of any such foundry in North America. "It's faster and, costwise, the least expensive way to go. Also, in our case, customers are dealing with somebody that's in the United States, so they can reduce the time it takes to deliver a product by at least a third."

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

[ILLUSTRATION OMITTED]

Hamlin Casting alloys technology, automation and craftsmanship. The process starts with a blueprint from a customer such as Phoenix-based U-Haul Corp., Sidney, N.Y.-based Amphenol Aerospace Co. or nearby Mount Airy-based Pike Electric Corp. The desired part might be something weighing a few ounces or a 50-pound lighting fixture. "From that, we'd make a prototype," Welden says. Once it's finished, a conveyor in the 61,000-square-foot factory carries moisturized olivine sand, which is strengthened by clay and resists expansion when heated, into chambers where 1,000 pounds per square inch of pressure forces it around the pattern. What remains after the pattern is removed is the sand mold.

Aluminum ingots are fed into furnaces powered by fuel oil--up to 30,000 gallons annually--where the metal melts and flows into holding tanks. Workers use ceramic ladles to pour it into molds. After hardening, parts go through shake-out machines to remove residual sand. Finally...