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EXHIBIT 31a

CERTIFICATIONS

I, Michael E. Batten, certify that:

1.    I have reviewed this annual report on Form 10-K of Twin Disc,
      Incorporated;

2.    Based on my knowledge, this report does not contain any untrue statement
      of a material fact or omit to state a material fact necessary to make the
      statements made, in light of the circumstances under which such
      statements were made, not misleading with respect to the period covered
      by this report;

3.    Based on my knowledge, the financial statements, and other financial
      information included in this report, fairly present in all material
      respects the financial condition, results of operations and cash flows
      of the registrant as of, and for, the periods presented in this report;

4.    The registrant's other certifying officers and I are responsible for
      establishing and maintaining disclosure controls and procedures (as
      defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the registrant
      and have:

      a)  designed such disclosure controls and procedures, or caused such
      disclosure controls and procedures to be designed under our supervision,
      to ensure that material information relating to the registrant, including
      its consolidated subsidiaries, is made known to us by others within those
      entities, particularly during the period in which this report is being
      prepared;

      b)   evaluated the effectiveness of the registrant's disclosure controls
      and procedures and presented in this annual report our conclusions about
      the effectiveness of the disclosure controls and procedures, as of the
      end of the period covered by this annual report based on such evaluation;
      and

      c)   disclosed in this annual report any change in the registrant's
      internal control over financial reporting that occurred during the
      registrant's most recent fiscal quarter (the registrant's fourth fiscal
      quarter in the case of this annual report) that has materially affected,
      or is reasonably likely to materially affect, the registrant's internal
      control over financial reporting; and

5.    The registrant's other certifying officers and I have disclosed, based on
      our most recent evaluation of internal control over financial reporting,
      to the registrant's auditors and the audit committee of registrant's
      board of directors (or persons performing the equivalent functions):

      a)   all significant deficiencies and material weaknesses in the design
      or operation of internal control over financial reporting which are
      reasonably likely to adversely affect the registrant's ability to record,
      process, summarize and report financial information; and

      b)   any fraud, whether or not material, that involves management or
      other employees who have a significant role in the registrant's internal
      control over financial reporting.

Date: September 21, 2005                    /s/ MICHAEL E. BATTEN
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                                            Michael E. Batten
                                            Chairman, Chief Executive Officer