Frank Kurtis began building his own midget car chassis in the late 1930s, establishing Kurtis Kraft as a commercial operation. The company grew into one of the most prolific builders of American racing machinery of the postwar era, producing cars across multiple categories of oval-track competition. Kurtis Kraft created 387 midget cars in total — some fully ready to race, some requiring engines or other final components. Parts for several dozen additional cars were also sold, potentially as kits.
The combination of a Kurtis Kraft midget chassis with the smaller-displacement version of the Offenhauser motor became the dominant package in American midget racing, remaining at the front of that category for two decades. Frank Kurtis was later recognized as the first non-driver inducted into the National Midget Auto Racing Hall of Fame.
Kurtis Kraft's most significant impact came at the Indianapolis Motor Speedway. The company produced 120 cars intended for the Indianapolis 500, of which five went on to win the race. The concentration of Kurtis-built machinery at Indianapolis was significant enough that Kurtis cars shaped the competitive landscape of American open-wheel racing during the late 1940s and through the 1950s.
Because the FIA World Drivers' Championship included the Indianapolis 500 between 1950 and 1960, numerous Kurtis Kraft cars accrued World Championship race starts during that period. One Kurtis midget was also entered at the 1959 Formula One United States Grand Prix, driven by Rodger Ward. The car was not designed for international-style road racing and its engine was undersized for the Formula One regulations; Ward circulated at the back of the field for 20 laps before retiring with clutch problems.
Between 1949 and 1955, Kurtis built a small series of low, fibreglass-bodied two-seater sports cars under his own name in Glendale, using Ford running gear. Approximately 36 Kurtis Sport Cars were built before the licence was sold to Earl "Madman" Muntz, who used the platform as the basis for the Muntz Jet. In 1954 and 1955, road versions of their Indianapolis racers were also offered.
Frank Kurtis sold the midget car portion of the business to Johnny Pawl in the late 1950s, and sold the quarter midget business to Ralph Potter in 1962. Among the notable figures connected to Kurtis Kraft's early years, Zeke Justice and Ed Justice of the Justice Brothers automotive products company both worked at the firm after World War II, with Zeke Justice being its first employee.
Kurtis Kraft's legacy rests primarily on its dominance of American oval racing across multiple categories during the postwar period. Five Indianapolis 500 victories represent a level of success that only a handful of constructors have matched, and the midget car chassis remained a benchmark for durability and competitiveness for two decades. Frank Kurtis's influence on American open-wheel car construction was recognized through his induction into the National Midget Auto Racing Hall of Fame as an honorary member, and his work helped establish the technical foundations that American oval racing built upon through the 1950s and into the early 1960s.