<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS
<FISCAL-YEAR-END>                          JUN-30-1998             JUN-30-1998             JUN-30-1998
<PERIOD-START>                             JUL-01-1997             JUL-01-1997             JUL-01-1998
<PERIOD-END>                               SEP-30-1997             DEC-31-1997             MAR-31-1998
<CASH>                                           7,466                   3,982                   4,466
<SECURITIES>                                         0                       0                       0
<RECEIVABLES>                                   46,410                  46,329                  56,030
<ALLOWANCES>                                       375                     413                     533
<INVENTORY>                                     33,627                  40,054                  38,811
<CURRENT-ASSETS>                                91,389                  98,917                 108,488
<PP&E>                                         128,566                 144,067                 148,916
<DEPRECIATION>                                  27,464                  30,230                  32,814
<TOTAL-ASSETS>                                 218,148                 244,570                 256,651
<CURRENT-LIABILITIES>                           42,987                  44,052                  46,531
<BONDS>                                              0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0
<PREFERRED>                                          0                       0                       0
<COMMON>                                            82                      82                      82
<OTHER-SE>                                     124,576                 127,022                 131,048
<TOTAL-LIABILITY-AND-EQUITY>                   218,148                 244,570                 256,651
<SALES>                                         68,796                 153,231                 244,854
<TOTAL-REVENUES>                                68,796                 153,231                 244,854
<CGS>                                           59,584                 131,356                 208,859
<TOTAL-COSTS>                                    5,524                  13,011                  19,493
<OTHER-EXPENSES>                                    63                     179                     258
<LOSS-PROVISION>                                     0                       0                       0
<INTEREST-EXPENSE>                                 462                   1,285                   2,126
<INCOME-PRETAX>                                  3,163                   7,400                  14,118
<INCOME-TAX>                                     1,338                   3,185                   5,990
<INCOME-CONTINUING>                              1,825                   4,215                   8,128
<DISCONTINUED>                                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0
<CHANGES>                                            0                       0                       0
<NET-INCOME>                                     1,825                   4,215                   8,128
<EPS-PRIMARY>                                      .22                     .52                    1.00
<EPS-DILUTED>                                      .22                     .51                     .99
        

</TABLE>