EXHIBIT 5



                                   April 29, 1998



Tennant Company
701 North Lilac Drive
P.O. Box 1452
Minneapolis, MN 55440

     RE:       REGISTRATION STATEMENT ON FORM S-8 RELATING TO THE CASTEX
               INCORPORATED EMPLOYEES' RETIREMENT SAVINGS PLAN

Ladies and Gentlemen:

     In connection with the Registration Statement on Form S-8 under the
Securities Act of 1933, as amended (the "Registration Statement"), relating to
the offering of up to 50,000 shares of Common Stock, par value $.375 per share
(the "Shares"), of Tennant Company, a Minnesota corporation (the "Company"),
pursuant to the Castex Incorporated Employees' Retirement Savings Plan, I have
examined such corporate records and other documents, including the Registration
Statement, and have reviewed such matters of law as I have deemed relevant
hereto, and, based upon this examination and review, it is my opinion that all
necessary corporate action on the part of the Company has been taken to
authorize the issuance and sale of the Shares and that, when issued and sold as
contemplated in the Registration Statement, the Shares will be legally issued,
fully paid, and nonassessable under the current laws of the state of Minnesota.

     I am admitted to the practice of law in the state of Minnesota and the
foregoing opinions are limited to the laws of that state and the federal laws of
the United States of America.

     I consent to the filing of this opinion as an exhibit to the Registration
Statement.

                                   Very truly yours,

                                   /s/ Bruce J. Borgerding

                                   Bruce J. Borgerding
                                   Deputy General Counsel and
                                   Corporate Secretary