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                                                                    Exhibit 10.5
                                                                    ------------

                                PLEDGE AGREEMENT


     This PLEDGE AGREEMENT, dated as of October 14, 1998, between ACT
MANUFACTURING, INC. (the "Pledgor"), and THE CHASE MANHATTAN BANK ("Chase"),
                          -------                                   ----- 
individually and as collateral agent for the Lenders under the Credit Agreement
defined below, having an address at One Chase Square, Rochester, New York 14643
(the "Collateral Agent" and together with the Lenders, the "Secured Parties").
      ----------------                                      ---------------    

                              W I T N E S S E T H:

     WHEREAS, the Pledgor and its subsidiary, ACT Manufacturing Securities
Corporation, are entering into a Credit Agreement of even date herewith (as the
same may be modified, amended, supplemented or restated from time to time, the
"Credit Agreement"), with Chase, as administrative, documentation, collateral
 ----------------                                                            
and syndication agent, and the Lenders from time to time parties thereto; and

     WHEREAS, in connection with the execution and delivery of the Credit
Agreement, the Collateral Agent has requested that the Pledgor, and the Pledgor
has agreed to, enter into this Pledge Agreement (this "Pledge Agreement"),
                                                       ----------------
pursuant to which the Pledgor is pledging and granting a security interest in
the Pledged Collateral (as hereinafter defined) in favor of the Collateral Agent
for the benefit of the Secured Parties.

     NOW, THEREFORE, in consideration of the willingness of the Secured Parties
to enter into the Credit Agreement and of the Lenders to agree, subject to the
terms and conditions set forth therein, to make the Loans and issue Letters of
Credit to the Borrower pursuant thereto, and for other good and valuable
consideration, receipt of which is hereby acknowledged, it is hereby agreed as
follows:

     1.  Defined Terms. Except as otherwise expressly defined herein, all
         ------------- 
capitalized terms shall have the meanings ascribed to them in the Credit
Agreement.

     2.  Security Interest. The Pledgor hereby deposits with, and pledges to,
         -----------------
the Collateral Agent for itself and for the benefit of the other Secured
Parties: (a) the shares of capital stock listed on Schedule I hereto (the
                                                   ----------
"Pledged Stock") of the companies listed on Schedule I hereto (the "Companies"),
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(b) the instruments, agreements and other documents in favor of the Pledgor
listed on Schedule II hereto (the "Pledged Debt Documents"), and (c) any and all
          -----------              ----------------------
other additional investment property, securities, instruments and chattel paper
which may from time to time be pledged by the Pledgor to the Collateral Agent
for the benefit of the Secured Parties (the Pledged Stock, the Pledged Debt
Documents and all other additional investment property, securities, instruments
and chattel paper are sometimes herein referred to collectively as the "Pledged
                                                                        -------
Collateral"), and the Pledgor hereby grants to the Collateral Agent for itself
----------
and for the benefit of the other Secured Parties a security interest in all of
the Pledged Collateral as security for the due and punctual payment and
performance of the Secured Obligations described in Section 3 hereof.
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     3.  Secured Obligations. The security interest hereby granted shall secure
         -------------------
the due and punctual payment and performance of the following liabilities and
obligations of the Pledgor (herein called the "Secured Obligations"):
                                               -------------------   

         (a) Principal of and premium, if any, and interest on, and fees,
charges and other amounts due in respect of the Loans;

         (b) Any and all other obligations of the Pledgor to the Secured Parties
under the Credit Agreement or under any agreement or instrument relating
thereto, all as amended from time to time, including without limitation any
Interest Rate Protection Agreements; and

         (c) Any and all other obligations and Indebtedness of the Pledgor to
the Secured Parties or any of them, whether direct or indirect, absolute or
contingent, due or to become due, or now existing or hereafter arising,
including without limitation any and all other fees, premiums, and penalties
owing by the Pledgor to the Secured Parties or any of them.

     4.  Special Warranties and Covenants of the Pledgor. The Pledgor hereby
         -----------------------------------------------  
warrants and covenants to the Secured Parties that:

         (a) The Pledged Collateral is duly and validly pledged to the Secured
Parties in accordance with law, and the Pledgor warrants and will defend the
Secured Parties' right, title and security interest in and to the Pledged
Collateral against the claims and demands of all Persons whomsoever.

         (b) The Pledgor has good title to the Pledged Collateral, free and
clear of all Liens of every nature whatsoever except as expressly set forth or
permitted under the Credit Agreement.

         (c) All of the Pledged Stock has been duly and validly issued and is
fully paid and nonassessable.

         (d) If any additional shares of capital stock of any class of the
Companies or if any promissory notes of the Companies or other securities of the
Companies are acquired by the Pledgor after the date hereof, the same shall
constitute Pledged Collateral and shall be deposited with and pledged to the
Collateral Agent for itself and for the benefit of the other Secured Parties as
provided in Section 2 hereof simultaneously with such acquisition. The Pledgor
will promptly notify the Collateral Agent of the date and amount of any loans
made from time to time by the Pledgor to the Companies as permitted by the
Credit Agreement.

         (e) The Pledgor will not sell, convey or otherwise dispose of any of
the Pledged Collateral, nor will the Pledgor create, incur or permit to exist
any Lien whatsoever with respect to any of the Pledged Collateral or the
proceeds thereof, other than Liens on or in the Pledged Collateral created
hereby or which are otherwise required or permitted under the Credit Agreement.

         (f) The Pledgor will not consent to or approve the issuance of any
additional shares of capital stock of any class of the Companies, except for the
issuance of additional shares of capital stock to the Pledgor as permitted by
and in accordance with the terms of the Credit 


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<PAGE>
 
Agreement, provided that any such additional shares of capital stock shall be
deposited with and pledged to the Collateral Agent for itself and for the
benefit of the other Secured Parties simultaneously with such issuance as
provided in Section 2 hereof.

         (g) The Pledged Debt Documents evidence the amount of outstanding
indebtedness for money borrowed of the respective issuers thereof indicated on
Schedule II hereto.
-----------

         (h) If any additional instruments, agreements or other documents are
acquired by the Pledgor evidencing any additional indebtedness owing to the
Pledgor, the same shall constitute a part of the Pledged Debt Documents and
Pledged Collateral and shall be deposited with and pledged to the Collateral
Agent for itself and for the benefit of the other Secured Parties as provided in
Section 2 hereof simultaneously with such acquisition. The Pledgor will promptly
notify the Collateral Agent of any loans made from time to time by the Pledgor
as permitted by the Credit Agreement.

     5.  Distributions. In case, upon the dissolution, winding up, liquidation
         -------------
or reorganization of the Companies whether in bankruptcy, insolvency or
receivership proceedings or upon an assignment for the benefit of creditors or
any other marshaling of the assets and liabilities of the Companies or
otherwise, any sum shall be paid or any property shall be distributed upon or
with respect to any of the Pledged Collateral, such sum shall be paid over to
the Collateral Agent as collateral security for the Secured Obligations. In case
any stock dividend shall be declared on any of the Pledged Collateral, or any
share of stock or fraction thereof shall be issued pursuant to any stock split
involving any of the Pledged Collateral, or any distribution of capital
(excluding ordinary cash dividends) shall be made on any of the Pledged
Collateral, or any property shall be distributed upon or with respect to the
Pledged Collateral pursuant to recapitalization or reclassification of the
capital of the Companies, the shares or other property so distributed shall be
delivered to the Collateral Agent to be held as collateral security for the
Secured Obligations.

     6.  Events of Default. There shall exist a default under this Pledge
         -----------------  
Agreement upon the happening of any of the following events or conditions
(herein called "Events of Default"):
                -----------------

         (a) Default shall be made in the due and punctual payment of any
principal of or premium, if any, or interest on any of the Secured Obligations
as and when the same shall become due and payable (whether at maturity or at a
date fixed for any prepayment or installment or by declaration or acceleration
or otherwise) and such default shall continue beyond the expiration of the
applicable period of grace, if any; or

         (b) The breach, violation or other non-performance of any term,
covenant, condition, agreement or obligation of the Pledgor contained herein; or

         (c) Any other event of default (as defined or described in the Credit
Agreement) shall occur.

     7.  Rights and Remedies of Secured Parties. Upon the occurrence of any
         --------------------------------------
Event of Default, such default not having previously been remedied or cured, the
Secured Parties shall have the following rights and remedies:


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         (a) All rights and remedies provided by law, including, without
limitation, those provided by the Uniform Commercial Code;

         (b) All rights and remedies provided in this Pledge Agreement; and

         (c) All rights and remedies provided in the Credit Agreement, the
Notes, or in any other Facility Document, or in any other agreement, document or
instrument pertaining to the Secured Obligations.

     8.  Right to Transfer into Name of Collateral Agent, etc. In case there
         ----------------------------------------------------  
shall exist an Event of Default, but subject to the provisions of the Uniform
Commercial Code or other applicable law, the Collateral Agent may cause all or
any of the Pledged Collateral to be transferred into its name or into the name
of its nominee or nominees, as pledgee(s). So long as no Event of Default shall
exist, the Pledgor shall be entitled to exercise as the Pledgor shall deem fit,
but in a manner not inconsistent with the terms hereof or of the Secured
Obligations, the voting power with respect to its respective Pledged Collateral.

     9.  Right of Collateral Agent to Exercise Voting Power, etc. In case there
         -------------------------------------------------------
shall exist an Event of Default, the Collateral Agent shall be entitled to
exercise the voting power with respect to any or all of the Pledged Collateral,
to receive and retain, as collateral security for the Secured Obligations, any
and all dividends or other distributions at any time and from time to time
declared or made upon any of the Pledged Collateral, and to exercise any and all
rights of payment, conversion, exchange, subscription or any other rights,
privileges or options pertaining to the Pledged Collateral as if it were the
absolute owner thereof, including, without limitation, the right to exchange, at
its discretion, any and all of the Pledged Collateral upon the merger,
consolidation, reorganization, recapitalization or other readjustment of the
Companies or, upon the exercise of any such right, privilege or option
pertaining to the Pledged Collateral, and in connection therewith, to deposit
and deliver any and all of the Pledged Collateral with any committee,
depositary, transfer Collateral Agent, registrar or other designated agency upon
such terms and conditions as the Collateral Agent may determine, all without
liability except to account for property actually received, but the Collateral
Agent shall have no duty to exercise any of the aforesaid rights, privileges or
options and shall not be responsible for any failure to do so or delay in so
doing.

     10. Right of Collateral Agent to Dispose of Collateral, etc. Upon the
         -------------------------------------------------------
occurrence of an Event of Default, such default not having previously been
remedied or cured, the Collateral Agent shall have the right at any time or
times thereafter to sell, resell, assign and deliver all or any of the Pledged
Collateral in one or more parcels at any exchange or broker's board or at public
or private sale. Unless the Pledged Collateral is perishable or threatens to
decline speedily in value or is of a type customarily sold on a recognized
market, the Collateral Agent will give the Pledgor at least ten (10) days' prior
written notice at the address of the Pledgor specified in Section 20 hereof of
the time and place of any public sale thereof or of the time after which any
private sale or any other intended disposition thereof is to be made. Any such
notice shall be deemed to meet any requirement hereunder or under any applicable
law (including the Uniform Commercial Code) that reasonable notification be
given of the time and place of such sale or other disposition. Such notice may
be given without any demand of performance or other demand, all such demands
being hereby expressly waived by the Pledgor. All such sales shall be 


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<PAGE>
 
at such commercially reasonable price or prices as the Collateral Agent shall
deem best and either for cash or on credit or for future delivery (without
assuming any responsibility for credit risk). At any such sale or sales the
Collateral Agent may purchase any or all of the Pledged Collateral to be sold
upon such terms as the Collateral Agent may deem commercially reasonable. Upon
any such sale or sales the Pledged Collateral so purchased shall be held by the
purchaser absolutely free from any claims or rights of whatsoever kind or
nature, including any equity of redemption and any similar rights, all such
equity of redemption and any similar rights being hereby expressly waived and
released by the Pledgor. In the event any consent, approval or authorization of
any governmental agency will be necessary to effectuate any such sale or sales,
the Pledgor shall execute, and hereby agrees to cause the Companies to execute,
all such applications or other instruments as may be required.

     The Pledgor recognizes that the Collateral Agent may be unable to effect a
public sale of all or a part of the Pledged Collateral by reason of certain
prohibitions contained in the Securities Act of 1933, as amended (the
"Securities Act") but may be compelled to resort to one or more private sales to
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a restricted group of purchasers, each of whom will be obligated to agree, among
other things, to acquire such Pledged Collateral for its own account, for
investment and not with a view to the distribution or resale thereof.  The
Pledgor acknowledges that private sales so made may be at prices and upon other
terms less favorable to the seller than if such Pledged Collateral were sold at
public sales without such restrictions, and that the Collateral Agent has no
obligation to delay sale of any such Pledged Collateral for the period of time
necessary to permit such Pledged Collateral to be registered for public sale
under the Securities Act.  The Pledgor agrees that any such private sale shall
not be deemed to have been made in a commercially unreasonable manner solely
because it shall have been made under the foregoing circumstances.

     11. Credit Agreement. Notwithstanding any other provision of this Pledge
         ----------------
Agreement, the rights of the parties hereunder are subject to the provisions of
the Credit Agreement, including the provisions thereof pertaining to the rights
and responsibilities of the Collateral Agent. Unless the context shall otherwise
clearly indicate, the terms "Secured Party" and "Secured Parties" as used herein
shall be deemed to include the Collateral Agent acting for itself and on behalf
of the other Secured Parties pursuant to the Credit Agreement. The term
"Collateral Agent" as used herein shall include The Chase Manhattan Bank or any
other Person acting as Collateral Agent for the Secured Parties pursuant to the
terms of the Credit Agreement.

     12. Collection of Amounts Payable on Account of Pledged Collateral, etc.
         -------------------------------------------------------------------
Upon the occurrence and during the continuance of any Event of Default or
default hereunder, the Collateral Agent may, but without obligation to do so,
demand, sue for and/or collect any money or property at any time due, payable or
receivable, to which it may be entitled hereunder, on account of, or in exchange
for, any of the Pledged Collateral and shall have the right, for and in the
name, place and stead of the Pledgor, to execute endorsements, assignments or
other instruments of conveyance or transfer with respect to all or any of the
Pledged Collateral.

     13. Care of Pledged Collateral in Collateral Agent's Possession. Beyond the
         ----------------------------------------------------------- 
exercise of reasonable care to assure the safe custody and presentation of the
Pledged Collateral while held hereunder, the Collateral Agent shall have no duty
or liability to collect any sums due in respect thereof or to protect or
preserve rights pertaining thereto, and shall be relieved of all responsibility
for the Pledged Collateral upon surrendering the same to the Pledgor.

                                       5
<PAGE>
 
     14. Proceeds of Collateral. The proceeds of any sale or sales of the
         ----------------------
Pledged Collateral, together with any other additional collateral security at
the time received and held hereunder, shall be received and applied: first, to
the payment of all costs and expenses of such sale, including reasonable
attorneys' fees; second, to the payment of the Secured Obligations in such order
of priority as the Collateral Agent shall determine, and third, any surplus
thereafter remaining shall be paid to the Pledgor or to whomever else may be
legally entitled thereto (including, if applicable, any subordinated creditor of
any Company or the Pledgor). By way of enlargement and not by way of limitation
of the rights of the Collateral Agent under applicable law or the Credit
Agreement, Notes, or other Facility Documents, but not withstanding any
provision of the Credit Agreement, Notes, or other Facility Documents to the
contrary, the Collateral Agent shall be entitled to allocate its application of
the Pledged Collateral, and the proceeds thereof, to the Secured Obligations
(including without limitation the Loans) in such proportions and in such order
as the Collateral Agent, in its sole discretion, shall decide. In the event the
proceeds of any sale, lease or other disposition of the Collateral hereunder are
insufficient to pay all of the Secured Obligations in full, the Pledgor will be
liable for the deficiency, together with interest thereon at the maximum rate
provided in the Loans, and the cost and expenses of collection of such
deficiency, including (to the extent permitted by law), without limitation,
reasonable attorneys' fees, expenses and disbursements.

     15. Waivers, etc. The Pledgor hereby waives presentment, demand, notice,
         ------------
protest and, except as is otherwise provided herein, all other demands and
notices in connection with this Pledge Agreement or the enforcement of the
Secured Parties' rights hereunder or in connection with any Secured Obligations
or any Pledged Collateral; consents to and waives notice of the granting of
renewals, extensions of time for payment or other indulgences to any Company or
the Pledgor or to any third party, or substitution, release or surrender of any
collateral security for any Secured Obligation, the addition or release of
persons primarily or secondarily liable on any Secured Obligation or on any
collateral security for any Secured Obligation, the acceptance of partial
payments on any Secured Obligation or on any collateral security for any Secured
Obligation and/or the settlement or compromise thereof. No delay or omission on
the part of the Secured Parties in exercising any right hereunder shall operate
as a waiver of such right or of any other right hereunder. Any waiver of any
such right on any one occasion shall not be construed as a bar to or waiver of
any such right on any future occasion. The Pledgor further waives any right it
may have under the Constitution of the State of New York, under the constitution
of any state in which any of the Pledged Collateral may be located or which may
govern the Pledged Collateral, or under the Constitution of the United States of
America, to notice (other than any requirement of notice provided herein) or to
a judicial hearing prior to the exercise of any right or remedy provided by this
Pledge Agreement to the Collateral Agent and waives its rights, if any, to set
aside or invalidate any sale duly consummated in accordance with the foregoing
provisions hereof on the grounds (if such be the case) that the sale was
consummated without a prior judicial hearing. The Pledgor's waivers under this
Section have been made voluntarily, intelligently and knowingly and after the
Pledgor has been apprised and counseled by its attorneys as to the nature
thereof and its possible alternative rights.

     16. Termination; Assignment, etc. This Pledge Agreement and the security
         ----------------------------
interest in the Pledged Collateral created hereby shall terminate when all of
the Secured Obligations have been paid and finally discharged in full; provided
that the Lenders are no longer obligated to make Loans or issue Letters of
Credit under the Credit Agreement. No waiver by the Collateral 

                                       6
<PAGE>
 
Agent or by any other holder of Secured Obligations of any default shall be
effective unless in writing nor operate as a waiver of any other default or of
the same default on a future occasion. In the event of a sale or assignment by
any Secured Party of all or any of the Secured Obligations held by it, any
Secured Party may assign or transfer its rights and interest under this Pledge
Agreement in whole or in part to the purchaser or purchasers of such Secured
Obligations, whereupon such purchaser or purchasers shall become vested with all
of the powers and rights of such Secured Party hereunder.

     17. Reinstatement. Notwithstanding the provisions of Section 16, this
         -------------
Pledge Agreement shall continue to be effective or be reinstated, as the case
may be, if at any time any amount received by any Secured Party in respect of
the Secured Obligations is rescinded or must otherwise be restored or returned
by any such Secured Party upon the insolvency, bankruptcy, dissolution,
liquidation or reorganization of any Company, the Pledgor or any other Credit
Party or upon the appointment of any intervener or conservator of, or trustee or
similar official for, any Company, the Pledgor, or any other Credit Party or any
substantial part of their respective properties, or otherwise, all as though
such payments had not been made.

     18. Governmental Approvals, etc. Upon the exercise by the Collateral Agent
         ---------------------------
of any power, right, privilege or remedy pursuant to this Pledge Agreement which
requires any consent, approval, qualification or authorization of any
governmental authority or instrumentality, the Pledgor will execute and deliver,
or will cause the execution and delivery of, all applications, certificates,
instruments and other documents and papers that the Collateral Agent may be
required to obtain for such governmental consent, approval, qualification or
authorization.

     19. Restrictions on Transfer, etc. To the extent that any restriction
         -----------------------------
imposed by the charter or by-laws of the Companies or any other document or
instrument would in any way affect or impair the pledge of the Pledged
Collateral hereunder or the exercise by the Collateral Agent of any right
granted hereunder, including, without limitation, the right of the Collateral
Agent to dispose of the Pledged Collateral upon the occurrence and during the
continuance of any Event of Default, the Pledgor hereby waives such
restrictions, and represents and warrants that it has caused the Companies to
take all necessary action to waive such restrictions, and the Pledgor hereby
agrees that it will take any further action which the Collateral Agent may
reasonably request in order that the Collateral Agent may obtain and enjoy the
full rights and benefits granted to the Collateral Agent by this Pledge
Agreement free of any such restrictions.

     20. Notices. All notices, consents, approvals, elections and other
         -------
communications hereunder shall be in writing (whether or not the other
provisions of this Pledge Agreement expressly so provide) and shall be deemed to
have been duly given if delivered in accordance with the terms of the Credit
Agreement.

     21. Miscellaneous. This Pledge Agreement shall inure to the benefit of and
         -------------
be binding upon the Collateral Agent and the Pledgor and their respective
successors and assigns, and the term "Secured Parties" shall be deemed to
include any other holder or holders of any of the Secured Obligations. In case
any provision in this Pledge Agreement shall be invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining
provisions shall not in any way be affected or impaired thereby. This Pledge
Agreement may be executed in any 

                                       7
<PAGE>
 
number of counterparts and by the different parties hereto on separate
counterparts, each of which shall be an original, but all of which together
shall constitute one instrument.

     22. Governing Law; Jurisdiction; Waiver of Jury Trial. THIS PLEDGE
         -------------------------------------------------
AGREEMENT, INCLUDING THE VALIDITY HEREOF AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER, SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE
LAWS OF THE STATE OF NEW YORK. The Pledgor, to the extent that it may lawfully
do so, hereby consents to service of process, and to be sued, in the state of
New York and any federal court located in the state of New York, as well as to
the jurisdiction of all courts to which an appeal may be taken from such courts,
for the purpose of any suit, action or other proceeding arising out of any of
its obligations hereunder or with respect to the transactions contemplated
hereby, and expressly waives any and all objections it may have as to venue in
any such courts. The Pledgor further agrees that a summons and complaint
commencing an action or proceeding in any of such courts shall be properly
served and shall confer personal jurisdiction if served personally or by
certified mail to it at its address provided in section 20 hereof or as
otherwise provided under the laws of the state of New York. THE PLEDGOR AND THE
COLLATERAL AGENT IRREVOCABLY WAIVES ALL RIGHT TO A TRIAL BY JURY IN ANY SUIT,
ACTION OR OTHER PROCEEDING INSTITUTED BY OR AGAINST THE PLEDGOR OR THE
COLLATERAL AGENT IN RESPECT OF ITS OBLIGATIONS HEREUNDER OR THE TRANSACTIONS
CONTEMPLATED HEREBY.

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                                       8
<PAGE>
 
     IN WITNESS WHEREOF, the parties have executed this Pledge Agreement as a
sealed instrument as of the date first above written.


                                 PLEDGOR

                                     ACT MANUFACTURING, INC.

                                     By: /s/ John A. Pino
                                        -------------------------------
                                        Name: John A. Pino
                                        Title: President

                                 COLLATERAL AGENT

                                     THE CHASE MANHATTAN BANK,
                                     as Collateral Agent for the Secured Parties

                                     By: /s/ Peter N. Langburd
                                        -------------------------------
                                        Name: Peter N. Langburd
                                        Title: Vice President