<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
UNAUDITED, CONSOLIDATED CONDENSED FINANCIAL STATEMENTS AND IS QUALIFIED IN ITS
ENTIRETY BY REFERENCE TO SUCH UNAUDITED CONSOLIDATED CONDENSED FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
                             
<PERIOD-TYPE>                   3-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               MAR-31-1999
<CASH>                                          96,508
<SECURITIES>                                         0
<RECEIVABLES>                                   77,315
<ALLOWANCES>                                   (1,370)
<INVENTORY>                                     46,700
<CURRENT-ASSETS>                               225,772
<PP&E>                                         374,126
<DEPRECIATION>                               (213,402)
<TOTAL-ASSETS>                                 419,260
<CURRENT-LIABILITIES>                           74,911
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        13,542
<OTHER-SE>                                     306,519
<TOTAL-LIABILITY-AND-EQUITY>                   419,260
<SALES>                                        136,909
<TOTAL-REVENUES>                               136,909
<CGS>                                          108,258
<TOTAL-COSTS>                                  113,389
<OTHER-EXPENSES>                                   640
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                             (1,049)
<INCOME-PRETAX>                                 23,929
<INCOME-TAX>                                     8,435
<INCOME-CONTINUING>                             15,494
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    15,494
<EPS-PRIMARY>                                     0.57
<EPS-DILUTED>                                     0.57