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                                                                     EXHIBIT 5.1

                                October 2, 1998




Hadco Corporation
12A Manor Parkway
Salem, NH 03079


Ladies and Gentlemen:

     We are acting as counsel to Hadco Corporation, a Massachusetts corporation
(the "Company") in connection with the registration on a Registration Statement
on Form S-4 (the "Registration Statement") and the prospectus forming a part
thereof (the "Prospectus") under the Securities Act of 1933, as  amended, of
$200,000,000 aggregate principal amount of the Company's 9 1/2% Senior
Subordinated Notes due 2008 (the "Exchange Notes") and the related guarantees
(the "Guarantees") of certain of the Company's subsidiaries named in the
Registration Statement (the "Guarantors"). The Exchange Notes and the Guarantees
are proposed to be issued under an indenture dated as of May 18, 1998 (the
"Indenture") among the Company, the Guarantors and State Street Bank and Trust
Company, as trustee, and the related Registration Rights Agreement (the
"Registration Rights Agreement"), dated May 13, 1998, among the Company, the
Guarantors and the Initial Purchasers (as defined in the Registration Rights
Agreement) in exchange for the Company's 9 1/2% Senior Subordinated Notes due
2008 (the "Original Notes") and related guarantees.


     We have examined such documents, records and matters of law as we have
deemed necessary for purposes of this opinion. We have assumed that the
Exchange Notes and the Guarantees will be executed and delivered as set forth in
the Registration Statement, the Prospectus and the Letter of Transmittal set
forth as an exhibit to the Registration Statement. We have assumed the
genuineness of all signatures and the conformity to original documents of all
copies of documents submitted to us as copies, whether certified or not. We
have assumed the conformity of the certificates for the Exchange Notes and the 
Guarantees to the specimens of the certificates, which are included as an
exhibit to the Registration Statement. We have assumed that the Exchange Notes,
the Guarantees and the Indenture have been duly authorized, executed and
authenticated in accordance with the terms of the Indenture by each of the
parties thereto. Our opinions expressed herein with respect to the validly and
binding effect the Exchange Notes and the Guarantees are qualified to the extent
that the validity and binding effect thereof may be limited by (i) applicable
bankruptcy, reorganization, arrangements, insolvency, fraud on creditors,
preference, moratorium or similar laws affecting the enforcement of creditors'
rights generally as at the time in effect and (ii) general principles of equity
(whether considered in a proceeding of law or in equity).
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Hadco Corporation
October 2, 1998
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     Based upon and subject to the foregoing, we are of the opinion that the
Exchange Notes and the Guarantees, when duly executed and authenticated in
accordance with the terms of the Indenture and delivered in exchange for the
Original Notes as contemplated in the Prospectus, will be valid and binding
obligations under the laws of the State of New York of the Company and the
Guarantors, respectively.

     We consent to the filing of this opinion as an exhibit to the Registration
Statement and to the reference to us under the caption "Legal Matters" in the
Registration Statement.



                                   Very truly yours,

                                   /s/ Testa, Hurwitz & Thibeault, LLP
                                   ------------------------------------------

                                   TESTA, HURWITZ & THIBEAULT, LLP