Notes to CoNsolidated FiNaNCial statemeNts The change related to acquisitions in 2010 reflects the purchase price allocation for the QM Bearing acquisition completed on September  21, 2010 and the City Scrap acquisition completed on December 31, 2010. “Other” primarily includes foreign currency translation  adjustments for 2010. Year ended December 31, 2010: Note 7 – Goodwill and Other Intangible Assets (continued) The following table displays intangible assets as of December 31: Intangible assets subject to amortization are amortized on a straight-line method over their legal or estimated useful lives, with useful  lives ranging from two years to 20 years. Intangible assets acquired were $111.4 million for the Philadelphia Gear acquisition and $35.5  million for the Drives acquisition. Intangible assets subject to amortization acquired in 2011 were assigned useful lives of five to 20 years  and had a weighted average amortization period of 16.7 years. Amortization expense for intangible assets was $14.0 million, $9.4 million and $12.8 million for the years ended December 31, 2011,  2010 and 2009, respectively. Amortization expense for intangible assets is estimated to be approximately $18.9 million in 2012; $17.5  million in 2013; $17.3 million in 2014; $17.2 million in 2015 and $16.8 million in 2016. THE TIMKEN COMPANY 56 2011 2010 Gross  carrying  amount  accumulated amortization  Net  carrying  amount  Gross  Carrying  Amount  Accumulated  Amortization  Net  Carrying  Amount  Intangible assets subject to amortization:  Customer relationships $ 189.9 $ 26.3 $ 163.6 $ 82.0 $ 18.6 $ 63.4 Engineering drawings – – –  2.0   2.0  – Know-how  17.0  1.5   15.5   2.1   1.0   1.1  Industrial license agreements  0.2  0.1   0.1   0.4   0.1   0.3  Land-use rights  8.6  3.8   4.8   8.2   3.3   4.9  Patents  2.5  1.7   0.8   4.4   3.3   1.1  Technology use  44.3  8.7   35.6   39.0   6.3   32.7  Trademarks  14.5  2.3   12.2   6.0   5.0   1.0  PMA licenses  8.8  3.1   5.7   8.8   2.7   6.1  Non-compete agreements  4.7  2.5   2.2   2.7   1.9   0.8  Unpatented technology  7.2  6.4   0.8   7.6   6.0   1.6  $ 297.7 $ 56.4 $ 241.3 $ 163.2  $ 50.2 $ 113.0  Intangible assets not subject to amortization:  Tradename $ 6.1 $  – $ 6.1 $ 2.0 $  – $ 2.0 FAA air agency certificates  14.2  –  14.2   14.2  –  14.2  $ 20.3 $  – $ 20.3 $ 16.2 $  – $ 16.2 Total intangible assets  $ 318.0 $ 56.4 $ 261.6 $ 179.4  $ 50.2 $ 129.2 Process  Industries Aerospace  and Defense Steel Total Beginning Balance $ 49.5 $ 162.6 $ 9.6 $ 221.7 Acquisitions  1.8  – 2.5 4.3  Other  (1.3)  (0.3)  –  (1.6) Ending Balance $ 50.0 $ 162.3 $ 12.1 $ 224.4