Egyptian President Anwar Sadat made a strong appeal to Congress yesterday for weapons, saying only half-jokingly, "I shall raise hell for them."

Sadat told members of the House and the Senate that, having demonstrated he is "a man of peace," he feels justified in demanding that the United States begin to supply him with some weaponry, since he is cut off from Soviet arms supplies.

"The last time I was here I was shy," Sadat told reporters after a meeting with the House International Relations Committee and the House leadership. "Now I am not shy anymore," he said, and "as a friend I can say, if they don't approve, I shall raise hell for them."

By the time Sadat emerged from a subsequent luncheon meeting with the Senate Foreign Relations Committee and Senate leaders, he exuberantly told reporters with a half grin that "I threatened them" if Egypt failed to receive American arms.

Sadat later added that of course he was joking about "threats." Some of Sadat's aides, however, appeared uneasy that his remark might be misconstrued. Sadat is extremely articulate, and his English is rather good, but its nuances sometimes cause him difficulty.

Although the arms issue dominated attention as Sadat made impressive appearances before the congressional group to plead his cause for peace, Carter administration policymakers were preoccupied with diplomatic strategy on the eve of Sadat's departure from Washington today. This strategy is the overriding issue behind the scenes.

President Carter and Sadat are expected today to pledge new determination to work for an Egyptian-Israeli agreement in principle that will deal with what Sadat calls, "the core" of a peace settlement, the Palestinian question.

This is expected to take the form of a reaffirmation of the declaration Carter issued when he met with Sadat briefly at Aswan, Egypt, on Jan. 4.

The Aswan declaration was intended to bridge, by ambiguity, Sadat's insistence that Arab Palestinians must be granted the right of "self-determination" in captured territory that Israel occupies, and Israel's adamant opposition to that language. Israeli Prime Minister Menachem Begin rejects "self-determination" on grounds it implies a future independent Palestinian state that could be "a moral danger" to Israel.

At Aswan, Carter committed himself to a solution that will "enable the Palestinians to participate in the determination of their own future." He also agreed that the Palestinian issue should be resolved "in all its aspects" and that the "legitimate rights of the Palestinian people" should be recognized.

Begin has never accepted this language according to informed sources, during Sadat's visit the Carter administration has been soliciting support from Israel's champions in Congress to gain Begin's adherence to this and other compromise language.

The objective is twofold: to produce agreement in principle to permit the stalled Egyptian-Israeli political negotiations to resume, and to draw Jordan into negotiations over the Palestinian issue. This would also relieve Egypt of opposition Arab charges that it seeks only a separate agreement with Israel.

Secretary of State Cyrus R. Vance met late yesterday with Sens. Jacob K. Javits (R-N.Y.) and Abraham A. Rioncoff (D-Conn.) at their request, he said, to keep them informed on the Sadat discussions. Vance scheduled a later meeting at the State Department with Sen. Henry M. Jackson (D-Wash.), another strong supporter of Israel.

Asked by reporters after an hour's meeting with Javits and Ribicoff if they had discussed arms for Egypt, Vance said. "No, we were dealing with broader issues, such as the statement of general principles."

Javits said Vance "brought us up-to-date on where the efforts to arrive at a statement of general principles stand now." He also said "there was no discussion of the arms request."

Another source said the administration is telling Israel's supporters that to recapture the lost momentum of the Egyptian-Israeli negotiations. Israel should move to broad language on principles, and leave contentious details to a later stage. Sadat publicly charged on Monday that Israel is "arguing over every single word or comma."

Some pro-Israeli members of Congress have told administration officials in private meetings this week that Sadat must be more forthcoming, rather than simply complaining about Israel's proposals.

Sadat was widely praised on both sides of Congress yesterday for his commitment to peace. House Democratic leader Jim Wright of Texas told him, "We honor you for what you are -- a man of peace."

House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said that in the closed meeting with House members Sadat had made "a real appeal for arms." On the Senate side, Jackson said Sadat "made a very good case for arms, going beyond his own country, into the situation in Africa."

Jackson and many other members of congress said that while Sadat said Egypt will never use its weapons against Israel again, they were troubled, nevertheless, about what might happen in the future with American weapons. Sadat, several members noted, also has not ruled out force for all time if his peace venture is wiped out.

Sadat did not ask in yesterday's meetings for specific weapons. He told reporters Monday night, however, that in addition to American F5E jet fighters, Egypt wants the most advanced supersonic F15s and F16s.

Last April Sadat asked the United States for 120 F5Es, but as he described it yesterday, he "was shy" then, and did not make a strong demand. The administration has been contemplating asking Congress to authorize the sale of about 50 F5Es to Egypt. Many members suspect that Sadat has raised his asking price to F15s and F16s largely for bargaining purposes.

Sen. Stephen J. Solarz (D-N.Y.) said Sadat stated yesterday that the F5 was "a tenth-rate plane." Even so, Solarz said, supplying F5s to Egypt would cross the existing dividing line between "lethal and nonlethal" military equipment.

"I think there obviously will be very real reservations in Congress," Solarz said, "about providing the Egyptians with a significant combat capacity, to the extent that there is a very real possibility that those weapons may ultimately one day be used against Israel if the peace process should collapse."

The "more sophisticated" the weaponry, Solarz said, "the less willing" Congress will be to sell them to Egypt.

Meanwhile, the White House and the State Department both sharply denied yesterday a published report that the administration made "no great protest" when it was informed Jan. 5 that Israel planned new settlements in occupied Arab territory. New Israeli settlements have been a highly inflamatory issue for Sadat.

White House spokesman Jody Powell said "it is incorrect to say the United States did not react strongly and immediately," referring to a report by columnist Joseph Kraft in The Washington Post yesterday. State Department spokesman Hodding Carter III issued a similar denial and made public a chronology stating that on Jan. 6, 10 and 27 President Carter registered concern with Begin about Israeli settlements on the West Bank of the Jordan River and in the Sinai peninsula.