<TABLE> <S> <C>

<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
<CURRENCY> US DOLLARS
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   12-MOS                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          MAY-31-1996             MAY-31-1997             MAY-31-1997             MAY-31-1997
<PERIOD-START>                             JUN-01-1995             JUN-01-1996             JUN-01-1996             JUN-01-1996
<PERIOD-END>                               MAY-31-1996             AUG-31-1996             NOV-30-1996             FEB-28-1997
<EXCHANGE-RATE>                                      1                       1                       1                       1
<CASH>                                          30,134                  27,904                  36,277                  37,258
<SECURITIES>                                         7                       7                       7                       7
<RECEIVABLES>                                   93,094                  87,160                  95,654                 103,893
<ALLOWANCES>                                         0                       0                       0                       0
<INVENTORY>                                     65,873                  72,820                  84,150                  94,048
<CURRENT-ASSETS>                               205,273                 221,605                 230,710                 250,323
<PP&E>                                         400,708                 410,366                 416,612                 421,284
<DEPRECIATION>                                 260,300                 268,438                 270,230                 271,586
<TOTAL-ASSETS>                                 375,890                 390,562                 404,501                 426,367
<CURRENT-LIABILITIES>                           88,739                  96,082                  96,523                 101,727
<BONDS>                                         90,231                  90,231                  90,231                  96,231
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                        37,053                  37,053                  37,053                  37,053
<OTHER-SE>                                      72,890                  82,316                  96,140                 107,306
<TOTAL-LIABILITY-AND-EQUITY>                   375,890                 390,562                 404,501                 426,367
<SALES>                                        497,240                 133,583                 271,571                 424,144
<TOTAL-REVENUES>                               499,624                 134,235                 272,890                 426,222
<CGS>                                          421,492                 122,744                 237,823                 362,540
<TOTAL-COSTS>                                  421,492                 122,744                 237,823                 362,540
<OTHER-EXPENSES>                                     0                       0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                              11,272                   2,722                   5,382                   8,053
<INCOME-PRETAX>                                 25,234                (11,865)                 (2,732)                  10,278
<INCOME-TAX>                                         0                (19,680)                (19,860)                (19,680)
<INCOME-CONTINUING>                             25,234                   7,815                  16,948                  29,958
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                    25,234                   7,815                  16,948                  29,958
<EPS-PRIMARY>                                     0.72                    0.22                    0.47                    0.84
<EPS-DILUTED>                                     0.70                    0.21                    0.46                    0.81
        

</TABLE>