<ARTICLE>                     5
<MULTIPLIER>                                   1000
<CURRENCY>                                     U.S. Dollars
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                                                    MAR-31-1998
<PERIOD-START>                                                       APR-01-1997
<PERIOD-END>                                                         SEP-30-1997
<EXCHANGE-RATE>                                                                1
<CASH>                                                                     60243
<SECURITIES>                                                                   0
<RECEIVABLES>                                                              65708
<ALLOWANCES>                                                                   0
<INVENTORY>                                                                58790
<CURRENT-ASSETS>                                                          216091
<PP&E>                                                                    287532
<DEPRECIATION>                                                                 0
<TOTAL-ASSETS>                                                            508109
<CURRENT-LIABILITIES>                                                     136587
<BONDS>                                                                     3538
<PREFERRED-MANDATORY>                                                          0
<PREFERRED>                                                                    0
<COMMON>                                                                      54
<OTHER-SE>                                                                360723
<TOTAL-LIABILITY-AND-EQUITY>                                              508109
<SALES>                                                                   200264
<TOTAL-REVENUES>                                                          200264
<CGS>                                                                      98730
<TOTAL-COSTS>                                                              98730
<OTHER-EXPENSES>                                                               0
<LOSS-PROVISION>                                                               0
<INTEREST-EXPENSE>                                                           568
<INCOME-PRETAX>                                                            50704
<INCOME-TAX>                                                               13690
<INCOME-CONTINUING>                                                        37014
<DISCONTINUED>                                                                 0
<EXTRAORDINARY>                                                                0
<CHANGES>                                                                      0
<NET-INCOME>                                                               37014
<EPS-PRIMARY>                                                               0.65
<EPS-DILUTED>                                                               0.65