TOKYO -- Carbon fiber may be best known for its use in golf clubs and jet planes. Yet the silvery black composite is extremely strong and light, and holds great potential as a steel substitute while automakers race to squeeze every extra mile from a gallon of gasoline.

Unfortunately, carbon fiber also is expensive - up to 30 times the price of steel.

Now three Japanese companies, which together control 70 percent of the global carbon fiber market, want to change all that. The players are Toray Industries Inc., Teijin Ltd. and Mitsubishi Rayon Co. And by boosting output and cutting costs, they aim to pioneer mass production of the futuristic material for widespread use in cars. They also are counting on some technical breakthroughs to bring down the cost.

The hurdles are still high. But the potential payoffs are too big to ignore.

Carbon fiber delivers the strength of steel at one-fifth the weight. By some estimates, a car's overall weight could be halved if carbon fiber composites are swapped for traditional steel in such parts as hoods, roofs, fenders, body panels, wheels, radiator panels or propeller shafts.

"But the first step is bringing down the cost," says Seiichiro Nohara, spokesman for the Japan Carbon Fiber Manufacturers Association. "It will help if gasoline prices keep climbing."

Imagine a cloth of tightly woven filaments, each a fraction of the width of a human hair and composed almost entirely of pure carbon atoms. That is raw carbon fiber, which is then in turn twisted into yarns, turned into fabric or molded with epoxy to form composite materials or carbon fiber-reinforced plastic parts.

Making the carbon filament is expensive and time consuming. Manufacturers take long strands of pitch, rayon or polyacrylonitrile, known as PAN, and bake them in ovens at temperatures of 3,600 degrees Fahrenheit. The heat treatment transforms this raw material into a fibrous product that is up to 95 percent pure carbon, making it very light and very strong.

Still new

Today, automotive uses account for less than 1 percent of world carbon fiber output, Nohara says. What little is used mostly finds its way into exotic performance cars.

Mazda's RX-8, Honda's Legend sedan and Mitsubishi's Pajero SUV already use carbon fiber driveshafts. In Europe, BMW's M3 has a carbon fiber roof.

Nissan's latest GT-R sports car has a carbon fiber engine underguard and radiator panel. But the car also has a $70,000 price tag to match the high-tech extravagance.

"This is very new technology and very expensive. I'm not sure if we can apply it to other cars," says Nissan r&d chief Mitsuhiko Yamashita.

Carbon fiber is one of the new materials Yamashita is looking at as Nissan tries to trim its average fleet weight. He believes widespread use is still five years away.

Ambitious Japan

Tokyo-based Toray, the world's top carbon fiber producer with 30 percent of the market, sees big growth coming soon. The company plans to open a $24.3 million automotive center in Nagoya next month. The goal is to develop low-cost carbon fiber composites for body panels and hybrid vehicles.

Teijin, which accounts for 20 percent of global output, plans to start supplying carbon-resin composites to makers of auto parts as early as 2010, through its subsidiary Toho Tenax.

Automotive sales account for just 3 percent of Teijin's carbon fiber business today, but that is seen rising to 7 percent by 2010, says Toho Tenax spokesman Kaoru Fujii.

Teijin aims to first make engine undercovers for high-range sports cars and then move toward mass market models when higher volumes bring down the price.

The reason carbon fiber remains pricey is twofold. First, it requires enormous amounts of energy to heat and treat fibers. Second, it takes hours to mold carbon fiber components.

Teijin wants to tackle the second problem by developing a 10-minute molding process, Fujii says. But that's still an eternity compared with one-second sheet metal stamping.

Cost control

Carbon fiber makers are counting on growing global demand to push up production and bring down prices. Toray forecasts annual output of all carbon fiber to climb to 53,000 tons in 2010, from about 35,000 tons last year.

And several trends are converging to spur demand.

New fuel economy regulations and record gasoline prices are forcing carmakers to slash vehicle weight. Meanwhile, soaring steel prices are eroding that metal's cost advantage.

The average price of cold rolled sheet steel in Japan shot up 27.8 percent between November and March to ¥101,000 ($959) a ton. Hot rolled sheet steel has climbed 22.9 percent to $1,050 per ton.

And the trend is expected to continue. Japanese steel makers already are seeking price increases of up to 40 percent this year in negotiations with automakers and other big customers, local media report.

Such outside factors will be key in clearing the road for carbon fiber. But Japanese carmakers are clearly banking on carbon fiber producers to make the needed breakthroughs.

Even Toyota, known for its penny-pinching, has plans on the drawing board.

At last October's Tokyo auto show, the company unveiled its 1/X concept car, which boasts a body frame made from carbon fiber reinforced plastic. Not only does it offer the same interior space as the popular Prius hybrid car, it weighs only one-third as much.