The ratings on Portland, Ore.-based Precision Castparts Corp. are supported by its leading niche positions in most of its markets, some business diversity, efficient operations, and a good overall financial profile. The ratings also take into account the highly cyclical nature of core markets and potential for additional acquisitions. Precision Castparts is a manufacturer of complex metal components and products, and the leader in large structural investment castings, airfoil castings, and forged components used primarily in jet aircraft engines. Similar components are manufactured for industrial gas turbines that are used to generate power. The company is also a major producer of fasteners and specialized metal products to the aerospace, automotive, and general industrial markets. The May 2006 $550 million acquisition