<TABLE> <S> <C>

<PAGE>
<ARTICLE> 5
<RESTATED> 
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS                   YEAR
<FISCAL-YEAR-END>                          JAN-31-1997             JAN-31-1997             JAN-31-1997             JAN-31-1997
<PERIOD-START>                             FEB-01-1996             FEB-01-1996             FEB-01-1996             FEB-01-1996
<PERIOD-END>                               APR-30-1996             JUL-31-1996             OCT-31-1996             JAN-31-1997
<CASH>                                          20,573                  17,821                  14,786                  15,642
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                   37,671                  34,843                  39,558                  43,696
<ALLOWANCES>                                       747                     751                     750                     227
<INVENTORY>                                     25,879                  26,757                  26,513                  36,002
<CURRENT-ASSETS>                                83,993                  79,640                  81,411                  98,629
<PP&E>                                         135,586                 141,241                 142,775                 155,801
<DEPRECIATION>                                  72,299                  74,670                  75,219                  74,408
<TOTAL-ASSETS>                                 149,395                 148,142                 153,290                 199,493
<CURRENT-LIABILITIES>                           31,908                  27,993                  30,054                  65,879
<BONDS>                                              0                       0                       0                       0
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                   4,950
<COMMON>                                         6,139                   6,079                   6,024                   6,024
<OTHER-SE>                                      88,638                  91,144                  92,998                  92,733
<TOTAL-LIABILITY-AND-EQUITY>                   149,395                 148,142                 153,290                 199,493
<SALES>                                         57,010                 111,815                 166,685                 218,485
<TOTAL-REVENUES>                                57,010                 111,815                 166,685                 218,485
<CGS>                                           37,345                  73,110                 108,820                 143,080
<TOTAL-COSTS>                                   49,945                  98,150                 146,220                 193,635
<OTHER-EXPENSES>                                   360                     615                     945                      65
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                                 211                     410                     620                   (200)
<INCOME-PRETAX>                                  6,730                  13,110                  19,550                  24,985
<INCOME-TAX>                                     2,340                   4,385                   6,460                   7,565
<INCOME-CONTINUING>                              4,390                   8,725                  13,090                  17,420
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                     4,390                   8,725                  13,090                  17,420
<EPS-PRIMARY>                                      .37                     .74                    1.11                    1.48
<EPS-DILUTED>                                      .37                     .74                    1.11                    1.48
        

</TABLE>