Supreme Court nominee Robert H. Bork concluded his grueling testimony before the Senate Judiciary Committee yesterday with a pledge that he will never stray from his fundamental belief that a judge's job is to "interpret the law and not to make it."

After almost 30 hours of testimony on an extraordinary range of legal and political issues, Bork sought to reassure the committee that if confirmed he would adhere to high-court precedents, pose no threat to the rights of women or minorities and "give everybody a fair shake."

He also sought to rebut the charge that he has undergone a "confirmation conversion," an issue that took on increasing importance as the focus of the hearings shifted during the week from the portrayal of Bork as an unbending conservative ideologue to the suggestion that he was deliberately shading some of his opinions to win Senate votes.

Noting that he had retracted some of his longstanding views but forcefully reiterated others, Bork said:

"As a consequence, I have received criticism in some quarters for being too rigid and from other quarters for being inconsistent or self-contradictory. Neither charge, in my opinion, is accurate."

Bork, a former Yale Law School professor and judge on the U.S. Court of Appeals here since 1982, said the only significant change had been in his role -- from an academic, legal theorist to that of a judge.

"I really haven't shifted that much," he said.

At the close of Bork's testimony, both sides in the bitter dispute over his confirmation claimed to have made progress during the first week of hearings.

After the hearing ended, President Reagan telephoned Bork and told him that during his testimony "you demonstrated yet again your qualifications to serve on the highest court," a White House spokesman said yesterday.

Tom C. Korologos, a lobbyist brought in by the Reagan administration to help in the confirmation fight, said he is confident Bork will have at least 50 votes on the Senate floor, where the issue will be decided.

But Ralph G. Neas, executive director of the Leadership Conference on Civil Rights, said Bork damaged himself in his testimony.

"The Bork nomination was in bad shape coming into the week. And it is in worse shape now," he said.

Despite these conflicting assertions, neither side could claim to have picked up the support of the key Judicary Committee members who are considered undecided -- Sens. Dennis DeConcini (D-Ariz.), Howell Heflin (D-Ala.) and Arlen Specter (R-Pa.).

Specter questioned Bork extensively yesterday and appeared less skeptical than earlier in the week. But while saying he remained undecided, Specter also told Bork that his testimony had been "materially different" from some of his writings and that he remained concerned about "the risks to the Constitution and the risks to the court" should Bork be confirmed.

A pro-Bork strategist said privately that DeConcini appears to be the most likely of the three to oppose the nomination. Opposition to Bork by only one of the three would virtually assure that the best Bork could expect is a deadlocked committee that would send the nomination to the Senate floor with no recommendation.

When the hearings started on Tuesday, Bork's opponents were prepared to focus on his conservative views. They felt they could show the Senate that Bork was a rigid ideologue too far outside the mainstream to be confirmed.

Their goal was to give enough moderate senators a reason to vote against Bork, whether it was on a specific issue, such as civil rights or abortion, or his general view of how judges should interpret constitutional protections of individual rights.

But Bork quickly deflected that criticism by retracting some earlier positions he had taken and softening others. And he pledged that, if confirmed, he would not upset longstanding Supreme Court decisions protecting freedom of speech and guaranteeing due process and equal protection of the laws, even if he may disagree with those decisions.

Those responses, in line with the White House position that Bork is not a conservative activist, were meant to show Senate moderates that Bork's ardent supporters on the right and opponents on the left were both wrong -- that his confirmation would not push the evenly divided court to the right.

Bork emphasized his civil rights record during five years as a federal appeals court judge and 2 1/2 years as solicitor general. "Beginning with Brown v. Board of Education," Bork said, "I have supported black equality . . . I have never said anything or decided anything that should be frightening to women."

Bork argued that what he said and wrote as a professor to provoke discussion should not carry much weight. There was a difference, he said, between Bork as an academic and as a sitting judge, and the committee should focus on the latter, on what he said and did in his official actions.

The White House strategy has been aimed at narrowing opposition to where Bork's supporters want it -- to liberals who favor a right to abortion or racial hiring quotas. It also appeared to catch Bork's opponents off-guard, at least temporarily.

But for Bork supporters, the strategy has had a downside. It has raised questions, especially from key swing voters, about Bork's credibility or, in the phrase of Sen. Patrick J. Leahy (D-Vt.), about a "confirmation conversion." As such it provided ammunition for opponents and may have given some senators a new rationale for opposing the nomination -- his credibility and, as several key senators put it, his "predictability."

Korologos said yesterday he is not concerned that the focus shifted.

"I'd rather argue that argument than right-wing zealotry and ideology," he said.

Bork stressed several times during closing testimony that he believes judges "should interpret the law not make it," a theme the White House thinks should be especially appealing to undecided senators.

"I think it is the kind of argument the overwhelming majority of senators agree with," said White House lobbyist Will Ball. "It is the major argument of these proceedings and when it is over the argument on which most senators will cast their votes."

Bork's opponents also stressed their basic theme yesterday. Bork's confirmation, Sen. Edward M. Kennedy (D-Mass.) said, would "risk the danger that Judge Bork will use the Supreme Court to turn back the clock and refight settled battles" over civil rights, civil liberties and other issues.

Only a handful of the 14 Judiciary Committee members attended the unusual Saturday hearing and all praised Bork for his demeanor during his five days of testimony. Calling Bork a "dazzling" witness, Sen. Alan K. Simpson (R-Wyo.) said, "We'll never see this again."

Bork, in turn, praised committee Chairman Joseph R. Biden Jr. (D-Del.) for conducting fair hearings. Biden, who missed most of yesterday's hearing because he was attending his son's high school football game in Wilmington, said Bork is "a very bright man who has a view of the Constitution and of judging that is different from mine."

Seated alone at a long, rectangular table, Bork's discipline under the grilling cracked once near the end. When Specter said he had questions about the War Powers Resolution, a subject raised several times earlier, Bork groaned audibly. Catching himself, Bork said, "I'm sighing, senator, because I can't find that paper."

Specter's questions dominated the final session. Noting past Bork statements and rulings in favor of executive over legislative power, he said, "Why should we confirm a nominee who is likely to find against us" in disputes with the executive branch.

Bork insisted that "the impression that I always side with the president is wrong."

In pressing the issue of presidential power, Specter was picking up a theme sounded Friday by Majority Leader Robert C. Byrd (D-W.Va.), who said he is undecided on Bork.

Bork has said Congress should not be allowed to sue the president because that would strengthen power of judges, making them final arbiters of disputes between the other branches.

Byrd, who believes Congress does have a right to sue, said, "You're saying to Congress 'you ain't never going to get into this court.' We've got to go to some umpire or referee in the interests of the United States. You're saying let the Congress and executive {branches} engage in guerrilla warfare" to settle disputes. "That can greatly damage the country," he added.

Bork also reiterated yesterday his pledge to uphold Supreme Court precedents he severely criticized at the time they were made. "I'm not going to undo anything that's been done," he said.

If confirmed, Bork said, some of his rulings may anger liberals and some may anger conservatives. But those decisions, he continued, would not stem from "some personal, political agenda of mine" or "because of a desire to set a social agenda" for the country.

Asked by Simpson why he wants a seat on the Supreme Court, Bork said, "Our constitutional structure is the most important thing this nation has. And I would like to maintain it and be remembered for that."

With Bork off center stage, the committee will hear this week from dozens of individuals and organizations that support or oppose his confirmation. The hearings are expected to last two more weeks. They will resume Monday with testimony from the American Bar Association, which gave Bork a favorable rating in a divided and controversial vote.