<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>