Although it doesn't approach the scale of California's Silicon Valley or Boston's Rte. 128 corridor, the Washington area is fast becoming a major center of high-technology manufacturing.

The rapid growth in the local manufacturing economy belies the area's reputation as supporting only service industries. As a new set of manufacturing companies quietly springs up around the Beltway, Washington has become the fastest-growing metropolitan area in the nation for high-tech manufacturing jobs.

Between 1980 and 1986, according to a study by Grubb & Ellis Co., a national real estate firm, local high-tech manufacturing employment has increased 11.6 percent a year. The Grubb & Ellis survey also found Washington to be in the top four metropolitan areas for computer industry job growth.

While many local high-tech manufacturers rely heavily on contracts from the Pentagon and other federal agencies, an increasing number are finding customers in the private sector, and experts say much of the future growth in the local high-tech industry will come from commercial work.

The local high-technology manufacturing community includes makers of silicon wafers, printed circuit boards, computer parts and equipment, lasers and optics devices, medical instrumentation and biotechnology products.

"I came out here from Silicon Valley expecting to see nothing here, and I am amazed that there is a whole manufacturing industry that's building up here," said Doug King, vice president of the Eastern division of the American Electronics Association, which represents 3,700 electronics and software manufacturers around the nation. "This is the closest I've seen to Silicon Valley -- the dynamics particularly."

Although estimates of the size of the area's high-technology base vary, the Washington/Baltimore Regional Association says that over the past decade, the greater Washington area has become the home of more than 1,800 high-technology companies; 37 percent of them are manufacturing companies, according to Robert Grow, director of research for the association, an alliance of business leaders.

The area is "building up to the critical mass of a manufacturing base," said Marcus Fisk, a spokesman for the Center for Innovative Technology, a nonprofit organization in Herndon set up by Virginia officials to promote economic development and technology transfer to the private sector in the state.

Experts say local high-tech employers are able to hire from a large pool of technically trained people, and high-paying technical assembly jobs are drawing out-of-work laborers from West Virginia, rural Maryland and Pennsylvania to the Washington area.

"People who can't get jobs at McDonald's in Pittsburgh are drawn here like a magnet. With elementary computer training, they can get high-technology, well-paid manufacturing jobs," said F. Joseph Moravec, president of Leggat McCall/Grubb Ellis Inc., a division of Grubb Ellis that was involved in the employment study.

Although concentrated around the Beltway, the high-tech manufacturing boom is rapidly spreading outward, with companies locating their facilities on cheaper land in outlying counties and taking advantage of their proximity to Dulles International and Baltimore-Washington International airports to distribute their goods around the world.

"They are starting to refer to the Shenandoah and Roanoke Valleys all the way up to Northern Virginia as Silica Valley" because of the large number of manufacturers of fiber-optics telecommunications equipment there, Fisk said. Silica is a mineral used to make optical fibers. The mineral silica is the main component of glass optical fibers. "This place used to be all farmland and stuff like that," Fisk said. "Now you look at the number of industries here and you say something is really happening."

Economic development agency experts say Maryland and Virginia have developed their own high-tech characters, with Maryland drawing more biotechnology companies that can feed off of research conducted by the National Institutes of Health, the Food and Drug Administration, and other federal agencies, while Virginia draws more computer software and hardware firms doing work for the Pentagon and NASA.

Much of the push for the development of a high-tech manufacturing base in the area comes from the federal government and local defense contractors, which have sparked a cottage industry of manufacturing shops to supply electronic parts. "I think it is symbiotic between small components suppliers and DOD contractors," said Tony Clifford, director of corporate development for Quantex Corp., a Rockville maker of laser optics equipment for use in such projects as the Strategic Defense Initiative.

But officials of many local high-tech manufacturers say they are making more sales to companies that are members of the Fortune 1,000 than they are to the federal government.

"The government may still be {a company's} main customer, but they'll sell to a lot of other people too," King said.

Richard C. Litsinger, chairman and president of C3 Inc., a Herndon company that assembles and modifies computer systems for the government, said the growth of technology manufacturing in the Washington area is benefiting from technology advancements that are making components smaller and capable of being made in light industrial manufacturing facilities.

"As the technology moves on, you don't have to be a heavy manufacturer any more. You're seeing garage-size companies starting up that can make the equipment on a smaller scale and sell it as a third-party manufacturer," Litsinger said.

"We are seeing a resurgence in the Washington area, particularly in the Dulles corridor, of companies that are designing products and are in some cases manufacturing themselves or subcontracting out those products," he said. "A few years ago, almost all of that was done in Silicon Valley."

C3 does some of its own manufacturing of the electronic components it uses to modify computers and subcontracts out the manufacturing of other parts, some to local companies. "I am the customer to many of these companies that make us aware they have a better, cheaper floppy disk or hard disk," Litsinger said.

E-Systems Inc.'s Falls Church-based Melpar division, a large electronic-warfare contractor with two local plants, also relies on components from local firms. "We do business with a lot of small machine shops, sheet-metal shops and circuit board shops," said Tony DiPasquale, a spokesman for the company. "There are numerous ones in the area that support companies like Melpar. If we need large numbers {of components}, they are available at local shops."

Companies like Renex Corp. of Woodbridge say the increasing local availability of electronic parts makes Washington an attractive place to do business. Renex, employing 50 people, makes data communications controllers that allow non-IBM computer equipment to connect with IBM mainframe computers.

"It's inevitable somebody is going to recognize the potential in this market, and {that} somebody would start to make the integrated circuits that companies like ours can use to make communications equipment," said Renex President Ray Gwinn. Renex, which was founded seven years ago and had sales of $5.2 million last year, recently placed 361st on Inc. magazine's list of the 500 fastest-growing privately held companies in the nation.

Renex is an example of a Washington area maker of high-tech equipment that markets more to other companies than to the federal government. "The federal government accounts for very little of our business -- I would say about 2 percent," Gwinn said.

Mohamed El-Ezaby, president of Automata Inc., a Reston-based maker of circuit boards used to mount electronic components, said that while companies like his may not sell directly to the federal government, the presence of the government as an end user is an important factor in the Washington technology environment.

"We sell more in the commercial field, but the attractiveness is having that large buyer here," he said. Automata's customers include International Business Machines Corp. and local companies, such as Communications Satellite Corp. and C3. It expects to sell about $25 million worth of circuit boards this year, with about 60 percent of its output going into computer equipment, 20 percent into data communications devices and 20 percent into medical instrumentation.

While the federal government has served as a catalyst for many companies, according to Deborah Boudreau, manager of corporate marketing for the Montgomery County office of economic development, the key to steadily rising profits for many local technology companies lies in establishing markets in the private sector. Boudreau estimates that more than 50 percent of the revenue of high-tech companies in Montgomery County come from the private sector.

"The companies are very aware that if they concentrated their efforts on the federal government, they might be very vulnerable to what's being funded next year, and to make sure they aren't vulnerable they want a stream of income from another source," she said.

Quantex Corp.'s Clifford said that while his company gets about two-thirds of its annual $5 million in revenue from federal government contracts, it is concentrating on increasing its sales to the commercial sector. "For the company to really grow, you've got to make it in the commercial world and not be dependent on government contracts, and in the long run that's what we'd expect," he said.

What local high-technology companies manufacture:

37.1 percent make machinery, including office and computing machines and electronic computer terminal.

30 percent make electrical and electronic equipment, such as communications equipment, such as commuications equipment, radio and TV-receiving equipment, electrical and industrial apparatus and electric distributing equipment.

16.5 percent are chemical companies, including drug and biological engineering companies and other companies.

15.3 percent make instruments and related products, such as measuring and controlling devices, instruments to measure electricity, optical instruments and lenses, such as contact lenses, medical instruments and supplies, monitoring devices or heart problems and blood pressure, and photographic equipment and supplies.

1.1 percent are in other manufacturing fields, including guided missiles, aircraft and parts and petroleum refining.

Source: Washington/Baltimore Regional Association survey of 1,800 local high-technology firms, of which approximately 670 were in manufacturing businesses.