<ARTICLE> 5 <RESTATED> <MULTIPLIER> 1,000 <PERIOD-TYPE> 6-MOS <FISCAL-YEAR-END> DEC-31-1997 <PERIOD-END> JUN-30-1997 <CASH> 34,856 <SECURITIES> 0 <RECEIVABLES> 71,626 <ALLOWANCES> 1,466 <INVENTORY> 73,677 <CURRENT-ASSETS> 188,111 <PP&E> 617,941 <DEPRECIATION> 279,832 <TOTAL-ASSETS> 557,218 <CURRENT-LIABILITIES> 91,540 <BONDS> 77,987 <PREFERRED-MANDATORY> 0 <PREFERRED> 0 <COMMON> 4,409 <OTHER-SE> 315,240 <TOTAL-LIABILITY-AND-EQUITY> 557,218 <SALES> 443,952 <TOTAL-REVENUES> 448,158 <CGS> 390,409 <TOTAL-COSTS> 390,409 <OTHER-EXPENSES> 23,140 <LOSS-PROVISION> 0 <INTEREST-EXPENSE> 3,153 <INCOME-PRETAX> 24,679 <INCOME-TAX> 8,910 <INCOME-CONTINUING> 15,769 <DISCONTINUED> 0 <EXTRAORDINARY> 0 <CHANGES> 0 <NET-INCOME> 15,769 <EPS-PRIMARY> 0.60<F1> <EPS-DILUTED> 0.59<F1> <FN> <F1>Earnings per share have been restated to comply with SFAS No. 128. </FN>