Sal Maglie, who pitched for all three New York teams during the tumultuous baseball wars of the 1950's and who intimidated batters with hard looks and high, hard fastballs, died yesterday in a nursing home in Niagara Falls, N.Y. He was 75.

Timothy Gleason, a spokesman for the Niagara Falls Memorial Nursing Home, where Mr. Maglie had been living since suffering a stroke five years ago, said that the former pitcher had died of complications from bronchial pneumonia.

On the mound, Maglie had a gaunt look, a grim expression, a stubble beard, a great curveball -- and a high, hard one that earned him the nickname Sal the Barber.

But behind the special effects stood one of the most accomplished pitchers of his era, as well as a man whose wandering career symbolized the confrontations between the New York Giants and the Brooklyn Dodgers, and between both of them and the lordly Yankees.

To add to the drama, he was already an old pro of 33 by the time he began to make a mark in the major leagues, chiefly because he had started slowly in the minors and then spent four years in and out of the Mexican League. By the time he returned from that detour, he was nearing the age when most pitchers begin to lose it. Made Mark With Giants

But for Sal the Barber, life began in 1950 when he pitched 11 victories in a row for Leo Durocher's Giants and continued in 1951 with 23 victories and only 6 defeats on that pennant-winning team. He moved to the Cleveland Indians in 1955, the Dodgers in 1956, the Yankees in 1957 and the St. Louis Cardinals in 1958. He helped the Giants win another pennant in 1954, and his 13-5 record for Brooklyn in 1956, along with a no-hitter in September, put the Dodgers in the World Series, too.

He will endure for his achievements as a pitcher, but he holds the further distinction of being the last player to be a member of all three New York teams, two of which -- the Dodgers and Giants -- moved to the West Coast after the 1957 season.

By the time he switched to coaching after 1958, he had a record of 119 games won and 62 lost, for a .657 percentage, a 3.15 earned run average and 25 shutouts. He had pitched in three World Series, and he was the losing pitcher in 1956 when Don Larsen pitched the only perfect game in Series history. (Maglie allowed only two runs and five hits.)

Along the way, he acquired a reputation as a tough customer, although his first wife, Kathleen, who died in 1967, dissented: "He isn't tough at all. He lets his beard grow before a game so he'll look fierce. I used to wonder what people were talking about when they said he scowled ferociously at the batters. Then I stayed home one day and watched him on TV. I hardly knew him."

But to his teammates and rivals, Maglie was not only stern but also precise. To Roy Campanella, who had trouble hitting him before later catching him, he was an artist who drew the observation, "Now I know how he used to get me out." Climb in Minors

The man behind the strong right arm was born Salvatore Anthony Maglie in Niagara Falls on April 26, 1917, the son of a pipefitter from Italy who later owned a grocery store. He worked for his father and in a shipping department, then received a tryout with the Rochester club of the International League in 1937. The next summer he signed with the Buffalo team for $275 a month. He was so nervous he couldn't get the ball over the plate and eventually was demoted to the Pony League, a lower minor league, to polish his trade.

After winning 20 games in 1941 in the Eastern League, he was drafted by the Giants, but he went to work in a defense plant instead and did not make it to New York until the war ended in 1945. A year later, he jumped to the outlaw Mexican League, which was raiding American talent. There, he won 20 games two years in a row, but he returned home and was blacklisted by the major leagues.

Late in 1949, though, as he was preparing to go to Venezuela, he was suddenly reinstated by Commissioner Albert B. (Happy) Chandler.

The next season, he worked ineffectively in Durocher's bullpen, did not pitch for one month, then was started by Durocher on July 24 after the Giants had lost nine straight. Maglie won his next 11 decisions, pitching four shutouts in a row, and finished with 18 victories. He was an instant hero at the age of 33.

In 1951, he did even better, winning 23 games while the Giants made their famous stretch run against the Dodgers. He also won 10 straight that summer, was the winning pitcher in the All-Star Game and came back in 1952 to win 18 more.

Four years later, when he was 39, he helped pitch his old Dodger enemies to the National League pennant and even contributed a no-hitter against Philadelphia. The following summer, he completed his New York trilogy by working for the Yankees.

After that, he revived stories of his famous brushback pitch as a coach with the Boston Red Sox, who dismissed him the day after they lost the 1967 World Series to St. Louis. He returned briefly as a pitching coach with the Seattle Pilots before putting his legends behind him for good and heading back to Niagara Falls.

Mr. Maglie is survived by his second wife, Doris; a son, Joseph, who is serving in the Air Force in Arkansas; a stepdaughter, Holly Fuhr; one grandchild, and a sister, Carmen Mancuso of Niagara Falls.

Salvatore A Maglie sr