Dan DiMicco has presided over stunning growth at Charlotte steel maker Nucor Corp. "I pinch myself when I look at where we are and where we were in 2000," said DiMicco, CEO since September of that year. "We exceeded our expectations."

During his tenure, sales more than tripled, to $14.75 billion. Earnings are more than five times higher, and Nucor's stock has soared from a low of $7.50 in 2000 to $69.25 Friday. The company has vaulted to No. 161 from 373 on the prestigious Fortune 500 listing.

Last year, construction in the commercial and energy sectors, as well as continued acquisitions, helped boost sales and push Nucor profits up more than one-third. The company's steel is used for products that include beams for highway overpasses, bolts for farm equipment, steel joists and girders for condo towers and sheet steel for refrigerators and water heaters.

Nucor's performance, including a stock increase of nearly 64 percent last year, propelled it to the top of the Carolinas 100, a ranking of public companies important to the two states.

Dividends have rewarded shareholders, with payouts jumping from $62 million in 2003 to $578 million last year.

This year, Nucor's stock is up 26.7 percent.

The company, named Nucor in 1972, grew from a nearly bankrupt conglomerate to an international steel legend during its first 25 or so years. Nucor revolutionized the steel industry, proving that so-called "mini-mills" could efficiently and profitably transform old cars, fridges and other scrap into steel. The mills, using electric furnaces, are cheaper to build and operate than old-line blast furnaces that make steel from iron ore.

Nucor touts its role as a major recycler, with a Web site counter that tallies tons of scrap recycled.

DiMicco is building the Nucor of the 21st century, which includes working on ways to make its raw material and use more environmentally friendly processes. Castrip, for example, enables molten steel to be formed without the extensive rolling typical in a steel mill. Think of it as pouring a giant cookie, at just the desired thickness, without using a rolling pin to flatten the dough. The streamlined process, for which Nucor has exclusive U.S. and Brazil rights, uses less energy and reduces emissions and allows for much smaller mills.

For Nucor, continuing a run of three record years could be hard as the industry faces weak home sales and rising steel imports. Acquisitions, which helped drive Nucor's recent growth, could become more expensive. But strong management, low production costs, an unusually diversified product line and new technologies have Nucor well-positioned.

"I never once thought that the team they put together couldn't do this," said Michelle Applebaum, an industry analyst. "The legacy is built-in growth."

DiMicco, with Nucor for 25 years, talked about where the company is headed. Applebaum, who owns Nucor stock, fielded questions separately. She has followed the company since 1981, for years on Wall Street and now through her boutique equity research firm, Michelle Applebaum Research, in Chicago.

Answers are edited for clarity and brevity.

Q: Steel is a cyclical industry, and there were rough spots early in your time as CEO. How does the industry landscape look today?

DiMicco: We feel good, but this is a business where you can't feel good for too long. We've accomplished a lot of growth through acquisitions and through some greenfields [new plants]. We're developing new technologies. I look forward to seeing them take root and have an impact on global steel-making and also from an environmental standpoint, to reduce energy consumption. We want to reward shareholders with earnings growth.

Q: What looks good this year?

DiMicco: Overall, we expect 2007 to be another very good year. I won't comment on whether it will be a record. Nonresidential continues to grow, driven in large part by the energy infrastructure -- oil platforms, drilling platforms, windmills, power plant construction. Also transportation, rail cars, barges.

Q: What are the challenges?

DiMicco: Last year, there was a new-record flood of imports. That created [excess] inventory. It has begun to correct itself.

Applebaum: Beyond the issues with international, particularly China, you're seeing domestic automotive is weak and anything related to housing -- appliances, lawn mowers, HVAC. We're starting to see some ...[new steel mill plans]. When it happens, that can bring prices down, although that's ... [years] away. That's a macro challenge Nucor faces. There's also competition for raw materials.

Q: Last year, Nucor formed Nexframe, a joint venture with home builder Lennar to tap the budding market for steel-framed homes. How's that going?

DiMicco: The housing market is a little bit in the tank, but that will change. On the upswing, I expect ... [it] will take off tremendously. We're already doing very well on the Gulf Coast.

Applebaum: Metal buildings in general will be a big market for them.

Q: Nucor has been on a buying spree of several years. What's next?

DiMicco: About half of our growth came from acquisitions. That's something this management team has focused on. We stick to three tenets. One: Do not overpay. Buy things that are compatible. And get into businesses we know something about. We'll continue to do acquisitions as they're at the right cost. That doesn't mean we have to steal them or buy at a fire sale, but they have to satisfy our internal rates of return.

Applebaum: Nucor is going from acquiring broken companies that only Nucor can fix to acquiring competitive, ongoing businesses, not turnarounds. These are different cultures, compatible, but different. I think they've got good genes for doing that well.

Q: Five years ago, Nucor opened an Indiana mill using Castrip steel-making technology. Where are you headed with this?

DiMicco: The benefit of the technology is you use less energy, significantly less emissions and lower cost. We're building our second plant in Arkansas. Hopefully, we're wrapping up sometime this year an international opportunity to build outside of North America with an international partner. That would be our first international steel-making venture. I don't want to pinpoint where we're looking. The one place we would not be looking is China. Some day they'll get serious about not stealing intellectual property, and we'll be able to do something there.

Q: Ken Iverson built Nucor into a globally known example of good management and profitable, low-cost steel-making. What will your legacy be?

DiMicco: Hopefully they'll look back and say, 'He took a good thing and made it better.' We've really had a good team. We did it by being true to the culture.