It's all for one and one for all in the workplace

''For Nippon Steel, the future does not look very bright,'' said Eishiro Saito. In the world of Japanese management, which is generally upbeat and optimistic, this statement by the chairman of the board of the world's largest steel company seems unusual.

But as long as the global economy remains in recession, Japan's steel industry, the most modern and efficient on earth, has little to cheer about. This year, Nippon Steel's production will dip below 30 million tons for the first time since the giant company was created in 1971 through the merger of the nation's top two steelmakers.

Nor are Japan's other steel mills doing any better. Total production this year may be less than 100 million tons for the first time since 1972. Yet the country's steel industry has probably coped more successfully with the oil shocks of 1973 and 1979 than its counterparts in the US and Western Europe.

It has invested heavily in energy-saving, nonpolluting, technology. In fiscal 1981, the industry consumed 73 percent less energy than in 1973. Automation and computerization continue. Workers are well paid and well motivated and participate loyally in the jishu kanrim system, a Japanese version of quality control. But Mr. Saito says that what his company and other major Japanese steelmakers cannot easily do is diversify into other fields.

''US Steel and Armco depend on steel for less than 50 percent of their income ,'' he said in an interview in his skyscraper office. ''But we cannot easily do the same.'' To take over unrelated enterprises in the energy field, as US Steel took over Marathon Oil, is, in Saito's opinion, unthinkable.

''Without steel there would be no automobiles, no modern buildings, no bridges,'' he said. ''The rest of industry relies on us to produce top-quality steel in all the shapes and forms needed. That is our mission.''

Many Japanese managers have a strong sense of mission. But among steelmen it takes on an almost religious conviction. So, when a world recession as pronounced and prolonged as the present one comes along, the best Saito and his fellow steel magnates can do is grit their teeth, pare operations, and wait for the upturn that will again enable them to fire up the blast furnaces.

They cannot lay off workers, because of the system of lifetime employment. And a mammoth company like Nippon Steel, with nine large and small mills spread across Japan, cannot easily concentrate operations in just its most modern installations. Such an attempt would cause wrenching dislocations in the communities that depend on the mills for a major share of their economic activities.

The steelworkers union, pacesetter for much of Japan's industry, cooperated this year by accepting wage increases of just under 7 percent. In difficult times, Saito commented, ''employers and employees share the sense of we-are-in-this-together. This alone can ensure corporate viability.''

As in other Japanese companies, decisionmaking at Nippon Steel is done by a combination of top-down and bottom-up procedures. Still, Saito's personal style, when president, was to reserve the major decisions for himself - after obtaining as wide a consensus as possible.

Nippon Steel's shares are spread widely. But the firm has no outside directors on its board, because, said Mr. Saito, that makes for a president accountable to too many interests.

So far, neither Nippon Steel nor any other major Japanese steelmaker has had to shut down an entire plant, as many US companies have done. Nippon has been invited to take over a US plant, under a joint venture. ''But we have been cautious about responding, and so far we have been unable to make up our minds, '' Saito said.

In the future, Nippon Steel, which had sales of about $12.6 billion last year , expects to promote steel-related projects such as the construction of high-rise ''new towns.'' Cost-efficiency, energy-saving, and new product development will also continue. ''We won't go into totally new areas such as ceramics,'' Saito said. ''But how about an unrustable steel?''