The propellers themselves were also found to be poorly manufactured, having been shaped by hand, with at least one cast at the wrong pitch. This was rectified by using a five-axis milling machine for future shaping work and replacing the miscast propeller. The material used for the propellers was also found to be weaker than expected, developing fatigue cracks after only a few years of use. Instead of going to Kockums, which had started to go into decline after the end of the Cold War, the submarine project office sent the propeller to the United States Navy for redesigning. Despite the Americans fixing the problems with the propeller design, resulting in significant performance improvements, the Swedish company was dissatisfied with the Australian actions; the dispatch of the propellers was one of the points of contention in the company's legal action in the mid-2000s against the Australian government over ownership of the intellectual property rights to the submarine's design.