Properties, Plants, and Equipment. Properties, plants, and equipment are recorded at cost. Depreciation is recorded
principally on the straight-line method at rates based on the estimated useful lives of the assets. The following table details the
weighted-average useful lives of structures and machinery and equipment by reporting segment (numbers in years):
Segment, Structures, Machinery and equipment
Engineered Products and Solutions, 29, 17
Global Rolled Products, 31, 21
Transportation and Construction Solutions, 27, 18