[On Brody, Wilkinson and Ober, P.C. Letterhead]


                                                                    July 8, 2005

Board of Directors
Acme United Corporation
1931 Black Rock Turnpike
Fairfield, CT 06825

Dear Sirs and Madam:

         We are corporate general counsel for Acme United Corporation (the
"Company"). We are delivering this opinion in connection with the filing with
the Securities and Exchange Commission (the "Commission") on or about the date
hereof of a Form S-8 Registration Statement (the "Registration Statement")
relating to (i) 280,938 shares of Common Stock, par value $2.50 per share, of
the Company (the "Common Stock") to be offered pursuant to the Acme United
Corporation 2002 Employee Stock Option Plan, as amended (the "Employee Plan");
and (ii) 50,000 shares of Common Stock to be offered pursuant to the Acme United
Corporation 2005 Non-Salaried Director Stock Option Plan (the "Director Plan")
(both the Employee Plan and the Director Plan collectively referred to herein as
the "Plans").

         We have examined and are familiar with (i) the Restated Certificate of
Incorporation and the Bylaws of the Company; (ii) the corporate proceedings
approving the Employee Plan, as amended, and the Director Plan; (iii) the Plans;
and (iv) such other documents and instruments as we have considered necessary
for the purposes of the opinions hereinafter set forth.

         In our examination of the aforesaid documents, we have assumed the
genuineness of all signatures, the legal capacity of all natural persons, the
accuracy and completeness of all documents submitted to us, the authenticity of
all original documents, and the conformity to authentic original documents of
all submitted to us as copies (including telecopies). This opinion letter is
given, and all statements herein are made, in the context of the foregoing.

         Based upon the foregoing, we are of the opinion that:

         1.       The Company has been duly incorporated and is a validly
                  existing corporation under the laws of the State of
                  Connecticut.

         2.       Upon issuance and delivery of the shares of Common Stock
                  pursuant to the Plans after the date hereof and payment to the
                  Company of the option price for the Common Stock, such shares
                  will be validly issued, fully paid, and nonassessable.


         This  opinion  letter is provided to you for your  benefit  solely with
regard  to the  Registration  Statement,  may be  relied  upon  by you  only  in
connection with the Registration Statement, and may not





Board of Directors, Acme United Corporation
July 8, 2005
Page 2


be relied upon by any other  person or for any other  purpose  without our prior
written consent.

         We are members of the bar of the State of Connecticut and some of us
are members of other jurisdictions not relevant herein. In connection herewith,
we express no opinion on the laws of any jurisdiction other than the laws of the
State of Connecticut.

         We hereby consent to the use of this opinion and our names in
connection with the Registration Statement filed with the Commission to register
the shares of Common Stock to be offered as aforesaid.

                                            Very truly yours,

                                            BRODY, WILKINSON AND OBER, P.C.


                                          By: /s/ James E. Rice
                                            ------------------------------
                                            James E. Rice, Vice President