Employes of Washington's biggest industry, the federal-military establishment, get a 7 percent raise in a couple of weeks. But workers in one of that industry's most prominent components -- the Congress -- are not guaranteed any raise whatsoever.

Rank-and-file bureaucrats and military personnel all get the 7 percent increase unless Congress vetoes it by Sunday night. It will not do that.

Senior federal executive, members of Congress and other important brass would get 5.5 percent under a plan approved by the House. But Capitol Hill employes who write bills, speeches and parking tickets, answer telephones, run flags up the pole and direct important committees, get nothing unless their boss gives it. No automatic raises for congressional employes.

(The Capitol Hill pay picture was further confused yesterday when the Senate Appropriations Committee approved 5.5 percent raises for senior government officials, but rejected the House-passed 5.5 percent raise for members of Congress.)

Locally, more than 300,000 white collar civil servants stand to get the 7 percent raise automatically in October. The same hold true for the 60,000 military personnel stationed here. And their bosses, now frozen at the $47,500 level would also get raises of up to 5.5 percent.

Legislative branch aides, however, don't get automatic increases. They normally qualify for the same amount as other federal workers -- but not automatically.

The legislative branch here consists of nearly 40,000 workers. That includes the Library of Congress, General Accounting Office, Government Printing Office and other units. Those people are due 7 percent. But other Capitol Hill aides won't necessarily get it.

With its GAO, GPO and Library of Congress workers, Congress is the largest employer in town. It is even bigger than HEW, which tries hard to be number one.

Currently, the Senate has about 6,700 employes who work for 100 Senators, staff committees and run offices. The House has about 11,500 workers, either in congressional offices or on committees. They are the people who get whatever the boss allows them to get.

Congressional insiders predict that some members of Congress, committee chairmen and their top aides will be rather selective with raises for employes. If members get 5.5 percent under the House plan, they might hold their employes to that amount. If they get zero, under the current Senate plan, they might be even less generous.

The final figure on congressional raises may be decided by a joint Senate-House conference committee. It could give members the 5.5 percent recommended by the House, or nothing as recommended by the Senate committee. Or it could compromise giving members 5.5 percent, and letting the Senate allow itself nothing. Since that would lead to House members earning more than senators, it isn't likely to happen.

Whatever the final figure, Capitol Hill employes won't know how much they will get until they are advised by their bosses sometime next month.