At A.R.C. Metal Recycling in Brooklyn, separating materials. The boom in metal has also led to more theft,

so recyclers must be vigilant about their sources.

Bob Rommeney steered his flatbed truck into a scrap-metal recycling plant in Brooklyn and unloaded two battered cars that had been wrecked days earlier at Riverhead Raceway on Long Island.

Within hours, the discarded vehicles would have their wheels removed, their fluids drained and their bodies crushed into 3-by-4-foot squares. Mr. Rommeney, 54, a retired city sanitation worker, would return home to Maspeth, Queens, about $400 richer.

“It’s worth it to come here and scrap the cars,” he said the other day, waiting his turn in the yard to drive his flatbed onto a large scale. There, workers compared its weight with what it weighed when it arrived at the yard, which is owned by A.R.C. Metal Recycling, to determine how much he should be paid. “Three years ago, I would have gotten about $50 a car,” Mr. Rommeney said. “The money went up.”

It is a very good time for anyone involved in the scrap-metal business. People who collect scrap metal and take it to recycling facilities are getting higher rates for their deliveries.

In turn, metal-recycling companies are selling more scrap metal, particularly to customers in China, India and other developing nations, who are paying record prices. A.R.C. Metal Recycling has recently been selling its scrap steel for close to $500 a ton, more than double the price it received a year ago.

“It’s booming, and it’s still growing,” said Michael Allocco, 24, the general manager of the A.R.C. recycling plant, one of 68 scrap metal processing firms licensed by the New York City Department of Consumer Affairs. The number of these businesses has grown nearly 20 percent in three years.

But the increase in the price of scrap metal has led to a rise in the theft of metal products, particularly anything made of copper. Mr. Allocco said he is vigilant about trying to ensure that none of the metal that is brought to his plant was stolen.

“I don’t accept the shopping-cart guys,” he said, adding that the police had visited the plant with photographs of people suspected of stealing metal, asking if anyone had seen them.

Mr. Allocco takes precautions like photographing his customers and keeping their driver’s licenses on file. “I try to keep the place on the up and up.”

Mr. Allocco’s plant is located in an industrial part of the Greenpoint neighborhood, alongside Newtown Creek and across the street from a new sewage treatment plant, whose bulbous towers add to a surreal landscape. Allocco Recycling, a transfer station for dirt, concrete and other types of fill, was founded by Mr. Allocco’s father on the two-and-a-half-acre site 20 years ago.

A.R.C., which is open 24 hours, buys hundreds of tons of ferrous metal a day. A large portion of it is steel.

At the plant, some of the oversize metal is fed to a huge hydraulic shearer resembling a Tyrannosaurus Rex. Its mighty jaws rear up and rip bulky metal items to pieces.

The arm of a heavy-duty material handler also routinely sweeps across the yard. Its enormous clawlike grapples release squirming loads of twisted metal onto a pile that rises 40 feet while awaiting compacting.

The company also buys thousands of pounds of nonferrous metal daily, which is placed in a warehouse, where a mound of brass car radiators sits alongside a collection of sinks, stacks of aluminum window frames and buckets of copper wiring.

“Nonferrous is worth more,” said Bill Monteleone, A.R.C.’s director of sales. He explained how customers are paid based on the type of metal they sell and whether they have separated the metals.

“The more you fine-tune it, the more you separate, the more money you get,” said Kevin Westhall, 39, who runs a small business removing items from the homes of people who have died. He strips the insulation from old copper wiring and he pries the nonferrous metal out of washing machines.

Separating the metal is hard work, said Mr. Westhall, who makes as many as five trips a day to the recycling yard. “I walk around like a magnet,” he said. “Metal is always on my mind.”

A.R.C. has more than 500 customers that sell to it regularly, including manufacturers, private sanitation and rubbish removal companies and major demolition contractors.

Among the items that have landed in the plant’s heap are miles of the metal bridge decking that made up the former left lane of the Brooklyn-Queens Expressway. It was deposited by the construction contractor who is rehabilitating that stretch of the highway.

The company also attracts smaller-scale customers, like Johnny Slavos, 23, whose ponytail dripped with sweat the other day as he unloaded a 100-pound Cadillac engine that he said he had picked up at a junkyard. He would not say anything more about where he collects scrap metal.

“I can’t tell you my secrets,” he said, explaining that he worried that others might elbow in on his turf. “It’s like the old gold rush.”

Alfred Tiscani, a longtime employee of A.R.C., said he is constantly amused by the variety of things that people bring in, displaying, for example, an ornate tin lamp that he was saving for his wife.

“When I see old cars, I feel bad,” he said, recalling the time someone brought in an antique B Model Mack Truck like the one his grandfather drove.

Nobody at the yard knows what happens to any of the scrap metal after it leaves the site. “Metal has no memory,” Mr. Monteleone said, looking down at the pen in his hand. “It could be made into this pen tip.”