<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS                   12-MOS
<FISCAL-YEAR-END>                          JUN-30-1997             JUN-30-1997             JUN-30-1997             JUN-30-1997
<PERIOD-START>                             JUL-01-1996             JUL-01-1996             JUL-01-1996             JUL-01-1996
<PERIOD-END>                               SEP-30-1996             DEC-01-1996             MAR-31-1997             JUN-30-1997
<CASH>                                           3,204                   2,626                   2,444                  19,819
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                   30,209                  37,066                  40,366                  40,310
<ALLOWANCES>                                       269                     374                     331                     381
<INVENTORY>                                     25,024                  28,566                  31,347                  30,867
<CURRENT-ASSETS>                                62,578                  72,296                  77,963                  94,833
<PP&E>                                          92,875                 107,402                 113,950                 118,110
<DEPRECIATION>                                  18,847                  20,782                  22,927                  24,994
<TOTAL-ASSETS>                                 158,177                 184,936                 195,532                 213,408
<CURRENT-LIABILITIES>                           30,199                  34,988                  37,447                  37,602
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                            56                      56                      56                      81
<OTHER-SE>                                      75,569                  77,897                  80,766                 122,650
<TOTAL-LIABILITY-AND-EQUITY>                   158,177                 184,936                 195,532                 213,408
<SALES>                                         48,998                 110,620                 176,933                 245,769
<TOTAL-REVENUES>                                48,998                 110,620                 176,933                 245,769
<CGS>                                           42,357                  93,868                 148,205                 203,386
<TOTAL-COSTS>                                    4,403                   9,551                  15,733                  22,191
<OTHER-EXPENSES>                                   (9)                      34                     111                     270
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                                 586                   1,463                   2,400                   3,227
<INCOME-PRETAX>                                  1,661                   5,704                  10,484                  16,695
<INCOME-TAX>                                       720                   2,392                   4,310                   6,967
<INCOME-CONTINUING>                                941                   3,312                   6,174                   9,728
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                       941                   3,312                   6,174                   9,728
<EPS-PRIMARY>                                      .17                     .60                    1.12                    1.68
<EPS-DILUTED>                                      .17                     .60                    1.11                    1.67
        

</TABLE>