<PAGE>   1
                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 10-Q

                  QUARTERLY REPORT UNDER SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934


                         For period ended April 30, 1998

                          Commission file number 0-588




                           COMMERCIAL INTERTECH CORP.
             (Exact name of registrant as specified in its charter)


             Ohio                                               34-0159880
----------------------------------------                   --------------------
(State or other jurisdiction of                             (I.R.S. Employer
incorporation or organization)                             Identification No.)

1775 Logan Avenue, Youngstown, Ohio                            44501-0239
----------------------------------------                   --------------------
(Address of principal executive offices)                    (Zip Code)

                                 (330) 746-8011
               --------------------------------------------------
               Registrant's telephone number, including area code


                                 Not Applicable
                                 --------------
    Former name, former address and former fiscal year, if changed since last
                                    report.


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter periods that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes  X  No
                                       ---    ---

Indicate the number of shares outstanding of each of the issuer's classes of
common stock, as of the latest practical date.

        Common Stock, $1 Par Value--14,255,317 shares as of June 9, 1998




<PAGE>   2



                                      INDEX

                           COMMERCIAL INTERTECH CORP.

<TABLE>
<CAPTION>
                                                                                                     Page No.
                                                                                                     --------

PART  I.       FINANCIAL INFORMATION


Item 1.        Financial Statements

<S>            <C>                                                                                       <C>
               Consolidated Condensed Statements of Income (unaudited) - Six Months and
               Three Months Ended April 30, 1998 and 1997................................................3

               Consolidated Condensed Balance Sheets (unaudited) -
               April 30, 1998 and October 31, 1997.......................................................4

               Statements of Consolidated Condensed Cash Flows (unaudited) - Six Months
               Ended April 30, 1998 and 1997.............................................................5

               Notes to Consolidated Condensed Financial Statements (unaudited) -
               April 30, 1998............................................................................6


Item 2.        Management's Discussion and Analysis of Financial Condition and
               Results of Operations.....................................................................9


PART II.       OTHER INFORMATION

Item 4.        Submission of Matters to a Vote of Security Holders......................................13

Item 6.        Exhibits and Reports on Form 8-K.........................................................13


SIGNATURE...............................................................................................14
</TABLE>




                                      -2-
<PAGE>   3




                          PART I. FINANCIAL INFORMATION

Item 1.  Financial Statements

                   COMMERCIAL INTERTECH CORP. AND SUBSIDIARIES
             CONSOLIDATED CONDENSED STATEMENTS OF INCOME (unaudited)

<TABLE>
<CAPTION>
                                                             Six Months Ended                   Three Months Ended
(Thousands of dollars, except per share data)                   April 30,                            April 30,
                                                        ---------------------------         ---------------------------
                                                           1998              1997             1998               1997
                                                        ---------         ---------         ---------         ---------

<S>                                                     <C>               <C>               <C>               <C>      
Net sales ......................................        $ 274,616         $ 246,608         $ 146,086         $ 129,892

Less costs and expenses:
    Cost of products sold ......................          207,819           184,771           110,015            96,368
    Selling, administrative and general expenses           44,564            45,502            22,811            22,758
                                                        ---------         ---------         ---------         ---------
                                                          252,383           230,273           132,826           119,126
                                                        ---------         ---------         ---------         --------- 

Operating income ...............................           22,233            16,335            13,260            10,766

Nonoperating income (expense):
    Interest income ............................              294               363               140               162
    Interest expense ...........................           (5,098)           (5,210)           (2,565)           (2,575)
    Foreign currency gains (losses) ............             (514)              450              (339)              (44)
    Other ......................................              437             1,819               484             1,285
                                                        ---------         ---------         ---------         ---------
                                                           (4,881)           (2,578)           (2,280)           (1,172)
                                                        ---------         ---------         ---------         ---------       

Income before income taxes .....................           17,352            13,757            10,980             9,594
Income taxes ...................................            6,474             5,065             4,010             3,854
                                                        ---------         ---------         ---------         ---------
Net income .....................................        $  10,878         $   8,692         $   6,970         $   5,740
                                                        =========         =========         =========         =========

Preferred stock dividends ......................             (927)             (963)             (462)             (450)
                                                        ---------         ---------         ---------         ---------
Net income applicable to common stock ..........        $   9,951         $   7,729         $   6,508         $   5,290
                                                        =========         =========         =========         =========
Earnings per share of common stock:
   Net income:
    Basic ......................................        $    0.72         $    0.57         $    0.47         $    0.39
    Diluted ....................................        $    0.63         $    0.51         $    0.40         $    0.34

Dividends per common share .....................        $   0.285         $   0.270         $   0.150         $   0.135
</TABLE>



See notes to consolidated condensed financial statements.

                                      -3-
<PAGE>   4



                   COMMERCIAL INTERTECH CORP. AND SUBSIDIARIES
                CONSOLIDATED CONDENSED BALANCE SHEETS (unaudited)

<TABLE>
<CAPTION>
(Thousands of dollars)                                                                  April 30,        October 31,
                                                                                           1998              1997
                                                                                        ---------         ---------
<S>                                                                                     <C>               <C>      
ASSETS
------
    CURRENT ASSETS:
        Cash and cash equivalents ..............................................        $  20,694         $  27,630
        Accounts receivable, less allowance (1998 - $3,183; 1997 - $2,456) .....           83,180            81,886
        Inventories ............................................................           62,024            60,944
        Deferred income tax benefits ...........................................           14,097            15,281
        Prepaid expenses and other current assets ..............................            3,324             4,255
                                                                                        ---------         ---------
                                                    TOTAL CURRENT ASSETS .......          183,319           189,996

    PROPERTY, PLANT AND EQUIPMENT ..............................................          221,495           216,030
        Less allowance for depreciation ........................................          118,079           112,604
                                                                                        ---------         ---------
                                                                                          103,416           103,426
    NONCURRENT ASSETS:
        Intangible assets ......................................................           43,534            44,460
        Pension assets .........................................................           44,660            42,961
        Other assets ...........................................................            2,551             3,955
                                                                                        ---------         ---------
                                              TOTAL NONCURRENT ASSETS ..........           90,745            91,376
                                                                                        ---------         ---------
                                                         TOTAL ASSETS ..........        $ 377,480         $ 384,798
                                                                                        =========         =========

LIABILITIES AND SHAREHOLDERS' EQUITY
------------------------------------
    CURRENT LIABILITIES:
        Bank loans .............................................................        $     492         $     140
        Accounts payable .......................................................           45,814            52,382
        Accrued expenses .......................................................           53,437            56,525
        Accrued income taxes ...................................................           10,274            11,085
        Dividends payable ......................................................            2,697             2,592
        Current portion of long-term debt ......................................            3,186             4,621
                                                                                        ---------         ---------
                                              TOTAL CURRENT LIABILITIES ........          115,900           127,345

    NONCURRENT LIABILITIES:
        Long-term debt .........................................................          111,565           111,342
        Deferred income taxes ..................................................           18,795            18,274
        Postretirement benefits ................................................           25,257            25,007
                                                                                        ---------         ---------
                                        TOTAL NONCURRENT LIABILITIES ...........          155,617           154,623

    SHAREHOLDERS' EQUITY:
        Preferred stock, no par value:
             Authorized:  10,000,000 shares
             Series A participating preferred shares ...........................                0                 0
             Series B ESOP convertible preferred shares
                 Issued:  1998 - 926,186 shares; 1997 - 942,552 shares .........           21,534            21,914
        Common stock, $1 par value:
             Authorized:  30,000,000 shares
             Issued:  1998 - 14,249,283 shares (excluding 1,943,566 in
                 treasury); 1997 - 14,125,175  shares (excluding
                 1,945,995 in treasury) ........................................           14,249            14,125
        Capital surplus ........................................................            3,733             5,264
        Retained earnings ......................................................           92,168            85,884
        Deferred compensation ..................................................          (15,080)          (16,337)
        Translation adjustment .................................................          (10,641)           (8,020)
                                                                                        ---------         ---------
                                         TOTAL SHAREHOLDERS' EQUITY ............          105,963           102,830
                                                                                        ---------         ---------
                         TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY ............        $ 377,480         $ 384,798
                                                                                        =========         =========
</TABLE>

See notes to consolidated condensed financial statements.



                                      -4-
<PAGE>   5


                   COMMERCIAL INTERTECH CORP. AND SUBSIDIARIES
           STATEMENTS OF CONSOLIDATED CONDENSED CASH FLOWS (unaudited)

<TABLE>
<CAPTION>
                                                                                     Six Months Ended
(Thousands of dollars)                                                                   April 30,
                                                                                 ------------------------
                                                                                   1998             1997
                                                                                  ------           ------
<S>                                                                              <C>              <C>     
OPERATING ACTIVITIES:
    Net income ..........................................................        $ 10,878         $  8,692
    Adjustments to reconcile net income to net cash provided by
       operating activities:
          Provision for depreciation and amortization ...................           7,995            7,280
          Amortization of deferred credit ...............................            (709)            (796)
          Postretirement benefit ........................................             376              179
          Pension plan credits ..........................................          (1,826)          (1,368)
          Change in deferred income taxes ...............................           1,732            1,651
          Change in current assets and liabilities:
              (Increase) in accounts receivable .........................          (2,483)          (2,951)
              (Increase) in inventories .................................          (2,077)            (622)
              Decrease (increase) in prepaid expenses and other
                  current assets ........................................             851           (1,885)
              Decrease in receivable from discontinued operations .......               0            6,771
              (Decrease) in accounts payable and accrued expenses .......          (7,592)          (5,496)
              (Decrease) increase in accrued income taxes ...............            (323)             159
                                                                                 --------         --------
                         Net cash provided by operating activities ......           6,822           11,614

INVESTING ACTIVITIES:
    Proceeds from sale of fixed assets ..................................           1,519              756
    Business acquisition ................................................               0          (39,359)
    Investment in intangibles ...........................................               0             (896)
    Capital expenditures ................................................          (8,952)          (3,798)
    Operating subsidies .................................................               0            3,016
                                                                                 --------         --------
                         Net cash (used) by investing activities ........          (7,433)         (40,281)

FINANCING ACTIVITIES:
    Proceeds from long-term debt ........................................          11,507           57,876
    Principal payments on long-term debt ................................         (12,756)         (22,295)
    Net borrowings under bank loan agreements ...........................             361           (4,889)
    Proceeds from reserve contracts .....................................             516                0
    Conversion of other assets ..........................................            (680)          (1,674)
    Dividends from discontinued operations ..............................               0            4,612
    Dividends paid ......................................................          (4,786)          (4,654)
                                                                                 --------         --------
                         Net cash (used) provided by financing activities          (5,838)          28,976

Effect of exchange rate changes on cash .................................            (487)          (3,014)
                                                                                 --------         --------
Net (decrease) in cash and cash equivalents .............................          (6,936)          (2,705)

Cash and cash equivalents at beginning of period ........................          27,630           27,552
                                                                                 --------         --------
Cash and cash equivalents at end of period ..............................        $ 20,694         $ 24,847
                                                                                 ========         ========

Supplemental disclosures:
    Cash paid during the period for:
       Interest .........................................................        $  4,640         $  5,406
       Income taxes .....................................................           5,066            3,255
</TABLE>

See notes to consolidated condensed financial statements.


                                      -5-
<PAGE>   6


                   COMMERCIAL INTERTECH CORP. AND SUBSIDIARIES
        NOTES TO CONSOLIDATED CONDENSED FINANCIAL STATEMENTS (unaudited)
                                 April 30, 1998

NOTE A - BASIS OF PRESENTATION

    The accompanying unaudited consolidated condensed financial statements of
Commercial Intertech Corp. and Subsidiaries (the "Company" or "Commercial
Intertech") have been prepared in accordance with generally accepted accounting
principles for interim financial information and with the instructions to Form
10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of
the information and footnotes required by generally accepted accounting
principles for complete financial statements. In the opinion of management, all
adjustments (consisting of normal recurring accruals) considered necessary for a
fair presentation have been included. For further information, refer to the
consolidated financial statements and footnotes thereto included in Commercial
Intertech Corp. and Subsidiaries' annual report on Form 10-K for the year ended
October 31, 1997. Operating results for the six-month and three-month periods
ended April 30, 1998 are not necessarily indicative of the results that may be
expected for the year ended October 31, 1998.

    In February 1997, the Financial Accounting Standards Board ("FASB") issued
Statement No. 128, "Earnings per Share." Statement No. 128 replaced the
previously reported primary and fully diluted earnings per share with basic and
diluted earnings per share. Unlike primary earnings per share, basic earnings
per share excludes any dilutive effects of stock options and convertible
securities. Diluted earnings per share is very similar to the previously
reported fully diluted earnings per share. All earnings per share amounts for
all periods have been presented, and where necessary, restated to conform to
Statement No. 128 requirements.

    Effective November 1, 1997, the Company adopted American Institute of
Certified Public Accountants Statement of Position ("SOP") 96-1, "Environmental
Remediation Liabilities." The SOP does not change existing accounting rules, but
clarifies how existing authoritative guidance on loss contingencies should be
applied in determining environmental liabilities. The adoption of the SOP did
not have a material impact on the Company's operations.

    Effective for the quarter ended January 31, 1998, the Company changed its
foreign currency translation procedures for its Brazilian operations reflecting
a change in its economy to a non-hyperinflationary status.
The change did not substantially impact the Company's financial statements.



                                      -6-
<PAGE>   7


NOTE B - PER SHARE DATA

    The computation of basic and diluted earnings per share is shown below:

<TABLE>
<CAPTION>
                                                                Six Months Ended                Three Months Ended
                                                                    April 30,                        April 30,
                                                          -------------------------         -------------------------
                                                            1998             1997             1998              1997
                                                          --------         --------         --------          -------
                                                                   (in thousands, except per share data)
<S>                                                       <C>              <C>              <C>              <C>     
Numerator:
Net income .......................................        $ 10,878         $  8,692         $  6,970         $  5,740
Series B preferred stock dividends ...............            (927)            (963)            (462)            (450)
                                                          --------         --------         --------         --------
    Numerator for basic earnings per share -
    net income applicable to common stock ........           9,951            7,729            6,508            5,290
Effect of dilutive securities - Series B preferred
    stock dividends and adjustments resulting from
    assumed conversion ...........................             802              796              418              371
                                                          --------         --------         --------         --------
Numerator for diluted earnings per share -
    net income applicable to common stock after
    assumed conversion ...........................        $ 10,753         $  8,525         $  6,926         $  5,661
                                                          ========         ========         ========         ========

Denominator:
Denominator for basic earnings per share -
    weighted average shares outstanding ..........          13,806           13,459           13,869           13,647
Effect of dilutive securities:
    Series B convertible preferred stock .........           2,824            2,996            2,800            2,849
    Assumed issuance of stock under stock option
       and award plans based on treasury stock
       method ....................................             469              350              438              348
                                                          --------         --------         --------         --------
Denominator for diluted earnings per share -
    weighted average shares outstanding and
    impact of dilutive securities ................          17,099           16,805           17,107           16,844
                                                          ========         ========         ========         ========

Basic earnings per share .........................        $   0.72         $   0.57         $   0.47         $   0.39
                                                          ========         ========         ========         ========

Diluted earnings per share .......................        $   0.63         $   0.51         $   0.40         $   0.34
                                                          ========         ========         ========         ========
</TABLE>


    Options to purchase 6,750 shares of common stock at $22.94 per share were
outstanding during the period ended April 30, 1998 but were not included in the
computation of diluted earnings per share because the exercise price of the
options was greater than the average market price of the common shares and,
therefore, the effect would be antidilutive.



                                      -7-
<PAGE>   8



NOTE C - INVENTORIES

    Inventories consisted of the following:

<TABLE>
<CAPTION>
                                                         April 30,     October 31,
                                                           1998            1997
                                                       -----------     -----------
                                                               (in thousands)

<S>                                                    <C>             <C>        
                 Raw materials ........................$    21,804     $    20,899
                 Work-in-process ......................     30,254          30,161
                 Finished goods........................      9,966           9,884
                                                       -----------     -----------
                                                       $    62,024     $    60,944
                                                       ===========     ===========
</TABLE>


NOTE D - SEGMENT REPORTING

    The Company is engaged in the design, manufacture and sale of products in
two segments:

<TABLE>
<CAPTION>
                                                             Six Months Ended                Three Months Ended
                                                                 April 30,                       April 30,
                                                         -------------------------        ----------------------
                                                           1998             1997            1998           1997
                                                         --------         --------        --------        ------
                                                                                 (in thousands)

<S>                                                    <C>             <C>              <C>            <C>        
             Hydraulic Systems
                 Net sales.............................$   192,340     $   168,311      $   102,617    $    90,104
                 Operating income......................     14,340          11,290            8,798          7,859
                    Percent to sales...................       7.5%            6.7%             8.6%           8.7%

             Building Systems and Metal Products
                 Net sales.............................$    82,276     $    78,297      $    43,469    $    39,788
                 Operating income......................      7,893           5,045            4,462          2,907
                    Percent to sales...................       9.6%            6.4%            10.3%           7.3%

             TOTAL
                 Net sales.............................$   274,616     $   246,608      $   146,086    $   129,892
                 Operating income......................     22,233          16,335           13,260         10,766
                    Percent to sales...................       8.1%            6.6%             9.1%           8.3%
</TABLE>



                                      -8-
<PAGE>   9


Item 2.      Management's Discussion and Analysis of Financial Condition and 
             Results of Operations


RESULTS OF OPERATIONS

Second Quarter 1998 Compared With Second Quarter 1997

            Quarterly net sales of $146,086,000 established a new record for the
Company. Net sales during the current quarter increased by $16,194,000 which is
13 percent higher, 15 percent higher on a currency adjusted basis, than the
second quarter of fiscal 1997. Net income increased by 21 percent to $6,970,000
during the second quarter of fiscal 1998 which primarily reflects the impact of
increased sales and the results of a previously implemented program to reduce
fixed costs.

            Net sales recorded by domestic operations totaled $87,053,000 during
the current quarter which was $14,666,000 or 20 percent higher than net sales of
the second quarter of the prior fiscal year. The domestic Hydraulics Systems
group recorded net sales for the quarter of $72,247,000, a 25 percent increase
over the second quarter of last year, as a number of domestic operations
achieved record performances for a second quarter. Net sales of the domestic
Metal Products group were flat compared with net sales of the same quarter last
year as demand slowed somewhat in the container and truck equipment markets.

            Net sales of foreign operations totaled $59,033,000 which was
$1,528,000 or 3 percent higher than the second quarter of last year. Net sales
of foreign operations would have been $3,608,000 or 6 percent higher if exchange
rates remained unchanged for the period. The foreign Hydraulic Systems group
reported shipments of $30,370,000, a 4 percent decline in the current quarter
adjusted for the effects of exchange rate differences which primarily reflects a
sales decline in the United Kingdom. Net sales of the Company's Astron Division
located in Europe increased 15 percent over the second quarter of last year.

            Consolidated gross profit of $36,071,000 was $2,547,000 or 8 percent
higher than the second quarter of fiscal 1997 which primarily reflects the
impact of increased sales during the current quarter. Gross profit margins for
the current quarter declined slightly compared with the second quarter of fiscal
1997; due, in part, to weaker sales for metal stampings in the United States and
hydraulic operations in the United Kingdom.

            Selling, general and administrative expenses of $22,811,000 were
approximately equal to expenses recorded in the same quarter last year. Selling,
general and administrative expenses declined as a percent of sales to 16 percent
in the current quarter from 18 percent of sales last year reflecting the impact
of the Company's previously implemented program to reduce its cost structure.

            Operating income of $13,260,000 in the current quarter was
$2,494,000 or 23 percent higher than the same quarter last year. Operating
income of the Hydraulic Systems group of $8,798,000 was 12 percent higher than
the same quarter last year as the domestic operations reported significantly
increased operating income. Operating income of the foreign operations of the
Hydraulic Systems group declined due to the lower earnings of the United Kingdom
operations which is primarily the result of distressed conditions associated
with export business caused by the strong local currency, continuing
difficulties caused by unreliable delivery of purchased components, and reduced
demand for industrial and specialty hydraulic products. The Building Systems and
Metal Products group recorded operating income of $4,462,000 which was 54
percent higher than operating income of the second quarter of last year. The
Company's Astron Division located in Europe recorded a significant increase in
operating income reflecting favorable climate and business conditions in the
current quarter. Operating income of the domestic Metal Products group


                                      -9-
<PAGE>   10


declined which primarily reflects the impact of decreased demand for certain
products during the current quarter.

            During the second quarter of fiscal 1998, nonoperating expenses of
$2,280,000 were $1,108,000 higher than the same quarter last year. Interest
expense declined slightly to $2,565,000 in the current quarter primarily due to
lower levels of debt partially offset by slightly higher average interest rates.
Foreign currency exchange and translation losses totaled $339,000 in the second
quarter of fiscal 1998 compared with a loss of $44,000 in the second quarter of
the prior year. Nonoperating income for the current quarter includes a gain on
the disposal of idle property located in Europe. In addition, nonoperating
income for the second quarter of the prior fiscal year includes a gain of $1.0
million realized on transfer of Astron Building Systems marketing and
manufacturing to a new Korean licensee.

            The Company's effective income tax rate amounted to 37 percent
during the second quarter of fiscal 1998 and 40 percent during the second
quarter of the prior fiscal year.

First Six Months of 1998 Compared With First Six Months of 1997

            The Company recorded net sales of $274,616,000 for the six months
ended April 30, 1998, surpassing the sales recorded for the prior year period by
11 percent, or 15 percent on a currency adjusted basis. Net income increased by
25 percent to $10,878,000 during the first six months of fiscal 1998 which
primarily reflects the impact of increased sales and the results of a previously
implemented program to reduce fixed costs.

            Net sales recorded by domestic operations totaled $161,927,000
during the current period which was $24,894,000 or 18 percent higher than net
sales of the prior year period. The domestic Hydraulics Systems group recorded
net sales for the period of $131,985,000, a 22 percent increase over the same
period of last year reflecting continued strength for operations in the United
States. The domestic Metal Products group reported a 3 percent increase in
revenues over the same period last year.

            Foreign operations recorded revenues of $112,689,000 which was
$3,114,000 or 3 percent higher than the same period of last year. Net sales of
foreign operations would have been $8,883,000 or 8 percent higher if exchange
rates remained unchanged for the period. The foreign Hydraulic Systems group
recorded net sales of $60,355,000 which were approximately equal to sales of the
prior period although up by 5 percent adjusted for the effects of exchange rate
differences. Net sales of the Company's Astron Division located in Europe
increased 6 percent over the same period last year (up 19 percent on a parity-
adjusted basis).

            Consolidated gross profit of $66,797,000 was $4,960,000 or 8 percent
higher than the same period of fiscal 1997 which primarily reflects the impact
of increased sales during the current period. Gross profit margins for the
current period declined slightly compared with the same period of fiscal 1997;
however, operating profit margins improved in the current period due to
declining operating expenses.

            Selling, general and administrative expenses of $44,564,000 declined
by $938,000 or 2 percent compared with the same period last year. Selling,
general and administrative expenses also declined as a percent of sales to 16
percent in the current period from 18 percent of sales in the same period last
year reflecting the impact of the Company's previously implemented program to
reduce its cost structure.


                                      -10-
<PAGE>   11


            Operating income of $22,233,000 in the current period was $5,898,000
or 36 percent higher than the same period last year. Operating income of the
Hydraulic Systems group of $14,340,000 was 27 percent higher than the same
period last year as the domestic operations reported significantly increased
operating income. Operating income of the foreign operations of the Hydraulic
Systems group declined due to lower earnings of the United Kingdom operations
which is primarily the result of distressed conditions associated with export
business caused by the strong local currency, continuing difficulties caused by
unreliable delivery of purchased components, and reduced demand for industrial
and specialty hydraulic products. The Building Systems and Metal Products group
recorded operating income of $7,893,000 which was 57 percent higher than
operating income of the same period of last year. Operating income of the
Company's Astron Division located in Europe increased significantly reflecting
favorable climate and business conditions during the current period. The
domestic Metal Products group recorded a slight increase in operating income
during the current period.

            During the first six months of fiscal 1998 nonoperating expenses of
$4,881,000 were $2,303,000 higher than the same period last year. Interest
expense declined by $112,000 to $5,098,000 in the current period primarily due
to lower levels of debt partially offset by slightly higher average interest
rates in the current period. Foreign currency exchange and translation losses
totaled $514,000 in the current period compared with gains of $450,000 in the
first six months of the prior year. Nonoperating income for the current period
includes a gain on the disposal of idle property. In addition, nonoperating
income for the same period of the prior fiscal year includes a gain of $1.0
million realized on transfer of Astron Building Systems marketing and
manufacturing to a new Korean licensee.

            The Company's effective income tax rate was 37 percent during the
first six months of both fiscal 1998 and fiscal 1997.


LIQUIDITY AND CAPITAL RESOURCES

            The Company expects that sufficient financial resources, generated
from both internal and external sources, will be available to meet operating
needs, to meet scheduled debt repayments and to fund capital expenditure
programs during the upcoming year. Cash and cash equivalents declined by
$6,936,000 during the first six months of fiscal 1998 and totaled $20,694,000 at
period end. Cash provided by operating activities during the current period was
$6,822,000 compared with cash provided of $11,614,000 in the first six months of
last year. The decrease is primarily attributable to the decrease of $6,771,000
in receivables from discontinued operations in the prior period.

            Cash used in investing activities was $7,433,000 in the first six
months of fiscal 1998 compared with $40,281,000 in the first six months of last
year which primarily reflects the use of cash totaling $39,359,000 to acquire
the common stock of Ultra Hydraulics Limited in the prior year. Capital
expenditures of $8,952,000 in the current period were $5,154,000 greater than
capital expenditures for the first six months of the prior year.

            Cash used by financing activities in the current period was
$5,838,000 compared with cash provided of $28,976,000 last year. Cash used in
financing activities in the current period reflects a net pay- down of long-term
debt of $1,249,000 in addition to dividends paid of $4,786,000. During the
current period quarterly cash dividends declared on the Company's common stock
was increased to $.15 per share which is 11 percent greater than the previous
rate of $.135 per share. The increased dividend is payable on June 15, 1998.
Cash provided by investing activities in the prior year period primarily
reflects the issuance of long-term debt to finance the acquisition of Ultra
Hydraulics Limited.


                                      -11-
<PAGE>   12


BUSINESS OUTLOOK

            Incoming customer orders received of $298,386,000 during the first
six months of fiscal 1998 is an all-time Company record. Current period orders
are 11 percent higher than orders received twelve months ago, parity adjusted.
Bookings for the first six months of fiscal 1998 for the Hydraulic Systems group
totaled $208,481,000, a 13 percent increase above the level recorded during the
same period last year. Bookings of $89,905,000 for the Building Systems and
Metal Products group were 5 percent greater than the amount recorded in the
first six months of the prior year.

            The worldwide backlog of unshipped orders amount to $217,855,000 at
April 30, 1998. The amount of unshipped orders is 11 percent higher than the
balance at the end of fiscal 1997 and 22 percent higher than the ending order
backlog twelve months ago, both adjusted for foreign currency exchange rate
differences.

            Management believes that the prospects for continued growth by the
Company remain excellent, however, some potentially limiting factors temper this
optimism including the possibility of slower growth for some hydraulic market
segments in the United States, sluggish performance for operations based in the
United Kingdom, and uncertainty regarding demand from customers in the metal
stampings industry. Therefore, quarter-over-quarter increases in income for the
second half of 1998 may not be as robust as reported for the first six months of
fiscal 1998. However, sustained year-over-year growth in bookings, expectations
for strong annual performance by Astron Building Systems, ongoing improvements
by the hydraulic operations in Germany, and expanded efforts to improve margins
in all units should more than offset these concerns.


FORWARD-LOOKING INFORMATION

            Forward-looking statements contained in this Form 10-Q government
filing are made pursuant to the safe harbor provision of the Private Securities
Litigation Reform Act of 1995. The Company cautions that a number of important
factors could cause the Company's actual results for 1998 and beyond to differ
materially from those expressed in any forward-looking statements made by or on
behalf of the Company. These important factors include, without limitation,
demand for the Company's products; the Company's ability to manufacture
commercial quantities of its products on an efficient and cost effective basis;
competition by rival developers of hydraulic systems and building systems and
metal products; changes in technology; customer preferences; growth in the
hydraulic systems and building systems and metal products industries; and
general economic and business conditions. These important factors and other
factors which could affect the Company's results are detailed in the Company's
filings with the Securities and Exchange Commission and are included herein by
reference. The Company assumes no obligation to update the information in this
filing.



                                      -12-
<PAGE>   13




                           PART II. OTHER INFORMATION

Item 4.     Submission of Matters to a Vote of Security Holders

            The Annual Meeting of Shareholders was held on March 25, 1998;
however, no matters were voted on which require disclosure under this item.


Item 6.     Exhibits and Reports on Form 8-K

      (a)   Exhibits:

             Exhibit 10.44 - First Amendment to Distribution and Interim
             Services Agreement by and between Commercial Intertech Corp. and
             CUNO Incorporated (filed herewith)

             Exhibit 11 - Statement re: Computation of Per Share Earnings
             (omitted - inapplicable)

                     The information with respect to the computation of both
                     basic and diluted earnings per share is presented in Note B
                     to the financial statements included in PART I, Item 1.

             Exhibit 27.1 - Financial Data Schedule for the six months ended
             April 30, 1998 (filed herewith)

             Exhibit 27.2 - Restated Financial Data Schedules for the three
             months, six months, nine months and year ended January 31, April
             30, July 31 and October 31, 1997, respectively, submitted pursuant
             to Item 601(c)(2)(iii) of Regulation S-K (filed herewith)

             Exhibit 27.3 - Restated Financial Data Schedule for the year ended
             October 31, 1996 submitted pursuant to Item 601(c)(2)(iii) of
             Regulation S-K (filed herewith)

        (b)  Reports on Form 8-K

             No reports were filed on Form 8-K during the quarter for which this
             report is filed.




                                      -13-
<PAGE>   14







                                    SIGNATURE


    Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                              COMMERCIAL INTERTECH CORP.



Date    June 9, 1998                          By    /s/Steven J. Hewitt
      --------------------------------          -------------------------------
                                                Steven J. Hewitt
                                                Senior Vice President and
                                                Principal Financial Officer



                                      -14-
<PAGE>   15



                           Commercial Intertech Corp.
                        Index To Exhibits Filed Herewith





Exhibit No.                Description
-----------                -----------

Exhibit 10.44    -   First Amendment to Distribution and Interim Services 
                     Agreement by and between Commercial Intertech Corp. and 
                     CUNO Incorporated.

Exhibit 27.1     -   Financial Data Schedule for the six months ended April 30, 
                     1998

Exhibit 27.2     -   Restated Financial Data Schedules for the three months, six
                     months, nine months and year ended January 31, April 30, 
                     July 31 and October 31, 1997, respectively, submitted 
                     pursuant to Item 601(c)(2)(iii) of Regulation S-K

Exhibit 27.3     -   Restated Financial Data Schedule for the year ended October
                     31, 1996 submitted pursuant to Item 601(c)(2)(iii) of 
                     Regulation S-K





                                      -15-