<TABLE> <S> <C>

<PAGE>

<ARTICLE> 5
<LEGEND>
RESTATED FDS INCLUDING COLUMNS FOR THE PRIOR THREE PERIODS ENDED (MARCH 31,
1996, JUNE 30, 1996, SEPTEMBER 30, 1996) AND PRIOR YEAR END (DECEMBER 31, 1995)
</LEGEND>
<MULTIPLIER> 1,000

<S>                             <C>                     <C>                     <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS                   9-MOS                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1996             DEC-31-1996             DEC-31-1996             DEC-31-1995
<PERIOD-START>                             JAN-01-1996             JAN-01-1996             JAN-01-1996             JAN-01-1995
<PERIOD-END>                               MAR-31-1996             JUN-30-1996             SEP-30-1996             DEC-31-1995
<CASH>                                           3,755                   3,797                   4,743                   9,507
<SECURITIES>                                         0                       0                       0                       0
<RECEIVABLES>                                   82,504                  93,603                  93,914                  78,385
<ALLOWANCES>                                       940                   1,220                   1,126                     868
<INVENTORY>                                     16,265                  16,968                  17,644                  16,418
<CURRENT-ASSETS>                               146,926                 153,488                 153,469                 147,395
<PP&E>                                         101,307                 101,998                 102,471                 100,096
<DEPRECIATION>                                  59,978                  61,477                  62,478                  58,351
<TOTAL-ASSETS>                                 200,621                 205,075                 204,632                 201,136
<CURRENT-LIABILITIES>                           64,689                  66,282                  66,226                  72,327
<BONDS>                                         18,000                  18,000                  15,000                  13,000
<PREFERRED-MANDATORY>                                0                       0                       0                       0
<PREFERRED>                                          0                       0                       0                       0
<COMMON>                                        33,549                  33,549                  33,549                  33,549
<OTHER-SE>                                      77,586                  80,373                  82,837                  75,393
<TOTAL-LIABILITY-AND-EQUITY>                   200,621                 205,075                 204,632                 201,136
<SALES>                                        115,966                 237,615                 358,410                 461,274
<TOTAL-REVENUES>                               115,966                 237,615                 358,410                 461,274
<CGS>                                          101,035                 207,006                 311,115                 398,732
<TOTAL-COSTS>                                        0                 207,006                 311,115                       0
<OTHER-EXPENSES>                                     0                       0                       0                       0
<LOSS-PROVISION>                                     0                       0                       0                       0
<INTEREST-EXPENSE>                                 277                     591                     906                   1,927
<INCOME-PRETAX>                                  5,210                  10,816                  15,953                  21,255
<INCOME-TAX>                                     2,036                   4,216                   6,250                   8,236
<INCOME-CONTINUING>                              3,174                   6,600                   9,703                  13,019
<DISCONTINUED>                                       0                       0                       0                       0
<EXTRAORDINARY>                                      0                       0                       0                       0
<CHANGES>                                            0                       0                       0                       0
<NET-INCOME>                                     3,174                   6,600                   9,703                  13,019
<EPS-PRIMARY>                                      .91                    1.89                    2.78                    3.74
<EPS-DILUTED>                                      .90                    1.87                    2.75                    3.72


</TABLE>