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EXHIBIT 4.1      SPECIMEN FORM OF COMMON STOCK CERTIFICATE.

TEMPORARY CERTIFICATE - EXCHANGEABLE FOR DEFINITIVE WHEN AVAILABLE

                                     STERIS

         NUMBER                     ("logo")                         SHARES
         T


               INCORPORATED UNDER THE LAWS OF THE STATE OF OHIO
                              STERIS CORPORATION
      This certificate is transferable in Cleveland, OH or New York, NY
                                                               CUSIP 859152 10 0

THIS CERTIFIES THAT



is the owner of

      FULLY PAID AND NON-ASSESSABLE COMMON SHARES, WITHOUT PAR VALUE, OF
                              STERIS CORPORATION
transferable on the books of the Corporation by the holder hereof in person or
by duly authorized attorney upon surrender of this certificate properly
endorsed. This certificate is not valid until countersigned by the Transfer
Agent of the Corporation and registered by the Registrar.
   WITNESS the facsimile signatures of the duly authorized officers of the
Corporation.

Dated




                      SECRETARY                 PRESIDENT


Countersigned and Registered:
        NATIONAL CITY BANK
        (Cleveland, OH)
                           Transfer Agent and Registrar,

BY

                              Authorized Signature


                           AMERICAN BANK NOTE COMPANY.
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                              STERIS CORPORATION

      As required by Ohio law, the Corporation will mail to the record holder of
this certificate, without charge, within five (5) days after receipt of written
request therefor addressed to the Secretary of the Corporation at its principal
place of business, a copy of the express terms of the shares represented by this
certificate and of all other classes and series of shares which the Corporation
is authorized to issue.

      The following abbreviations, when used in the inscription on the face of
this instrument, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM - as tenants in common         UNIF GIFT MIN ACT -      Custodian
TEN ENT - as tenants by the entireties                    ------         -------
JT TEN  - as joint tenants with right                     (Cust)         (Minor)
          of survivorship and not as tenants   under Uniform Gifts to Minors Act
          in common
                                                         ----------------------
                                                                 (State)
       Additional abbreviations may also be used though not in the above list.

FOR VALUE RECEIVED,                        HEREBY SELL, ASSIGN AND TRANSFER UNTO
                    -----------------------

PLEASE INSERT SOCIAL SECURITY OR OTHER
   IDENTIFYING NUMBER OF ASSIGNEE

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  (PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

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                                                                   OF THE SHARES
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REPRESENTED BY THE WITHIN CERTIFICATE AND DO HEREBY IRREVOCABLY CONSTITUTE AND
APPOINT
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ATTORNEY TO TRANSFER THE SAID SHARES ON THE BOOKS OF THE WITHIN-NAMED
CORPORATION WITH FULL POWER OF SUBSTITUTION IN THE PREMISES.

DATED                       19
      ---------------------   ----

                           -----------------------------------------------------
                           NOTICE: THE SIGNATURE TO THIS ASSIGNMENT MUST
                           CORRESPOND WITH THE NAME AS WRITTEN UPON THE FACE OF
                           THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT
                           ALTERATION OR ENLARGEMENT, OR ANY CHANGE WHATEVER.
Signature(s) Guaranteed:

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THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE
GUARANTOR INSTITUTION (BANKS, STOCKBROKERS, SAVINGS
AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH
MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE
MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15.

      THIS CERTIFICATE ALSO EVIDENCES AND ENTITLES THE HOLDER HEREOF TO CERTAIN
RIGHTS AS SET FORTH IN A RIGHTS AGREEMENT BETWEEN STERIS CORPORATION AND HARRIS
TRUST AND SAVINGS BANK, AS SUCCESSOR RIGHTS AGENT, DATED AS OF OCTOBER 24, 1996
(THE "RIGHTS AGREEMENT"), AS SUCH RIGHTS AGREEMENT MAY BE AMENDED FROM TIME TO
TIME THEREAFTER, A COPY OF WHICH IS ON FILE AT THE PRINCIPAL EXECUTIVE OFFICES
OF STERIS CORPORATION. UNDER CERTAIN CIRCUMSTANCES, AS SET FORTH IN THE RIGHTS
AGREEMENT, SUCH RIGHTS WILL BE EVIDENCED BY SEPARATE CERTIFICATES AND WILL NO
LONGER BE EVIDENCED BY THIS CERTIFICATE. STERIS CORPORATION WILL MAIL TO THE
HOLDER OF THIS CERTIFICATE A COPY OF THE RIGHTS AGREEMENT (AS IN EFFECT ON THE
DATE OF MAILING) WITHOUT CHARGE PROMPTLY AFTER RECEIPT OF A WRITTEN REQUEST
THEREFOR. UNDER CERTAIN CIRCUMSTANCES, RIGHTS WHICH ARE OR WERE BENEFICIALLY
OWNED BY ACQUIRING PERSONS OR THEIR AFFILIATES OR ASSOCIATES (AS SUCH TERMS ARE
DEFINED IN THE RIGHTS AGREEMENT) AND ANY SUBSEQUENT HOLDER OF SUCH RIGHTS MAY
BECOME NULL AND VOID.