no they did not. I posted this answer earlier. First of all, it was built in the 60s and the Kobe stuff was later.....then theres this.....Construction work began on the North Tower in August 1968 with construction beginning on the South Tower by January 1969.[137] In January 1967, $74 million in contracts were awarded to the Pacific Car and Foundry Company, Laclede Steel Company, Granite City Steel Company, and Karl Koch Erecting Company to supply steel for the project.[138] The Port Authority chose to use many different steel suppliers, bidding on smaller portions of steel, rather than buy larger amounts from a single source such as Bethlehem Steel or U.S. Steel as a cost-saving measure.[139]
so no, Kobe wasnt the steel company which produced the steel for the world trade towers.