<PAGE>

                                 EXHIBIT 10.5


                           HI-SHEAR TECHNOLOGY CORP.

              BUY-SELL AND VOTING AGREEMENT AND IRREVOCABLE PROXY

     THIS SHAREHOLDERS BUY-SELL AND VOTING AGREEMENT AND IRREVOCABLE PROXY
("Agreement") is entered into as of August 6, 1999, by and among HI-SHEAR
TECHNOLOGY CORP., a Delaware corporation (the "Company"), and Thomas R. Mooney
and George W. Trahan ("Mooney" and "Trahan", individually, and collectively, the
"Shareholders"), with respect to the following matters:

          A.   This Agreement shall replace that certain Buy-Sell Agreement
     between the Company and the Shareholders dated as of December 20, 1993.

          B.   The Shareholders together own in excess of a majority of the
     outstanding common stock shares of the Company (the "Shares").  As of the
     date of this Agreement, Mooney owns 2,700,000 Shares and Trahan owns
     2,180,580 Shares.  The Shareholders believe it is in their best interests
     to create a "voting proxy" between the Shareholders through the grant of a
     10-year irrevocable proxy from Mooney to Trahan of one-half of the excess
     of the Shares beneficially owned by Mooney over the Shares beneficially
     owned by Trahan according to the official stock transfer records of the
     Company on and as of the record date, as determined under Section 213 of
     the General Corporation Law of Delaware ("record date"), for any
     Shareholder vote taken (the "Proxy Shares").

          C.   The Shareholders acknowledge and agree that (1) on and as of each
     record date for a vote or written consent of Shareholders, the Inspector of
     Elections ("Inspector") shall determine the number of Proxy Shares subject
     to the Irrevocable Proxy, which determination shall be final and conclusive
     and (2) in the event the Inspector makes the determination that some or all
     of the Proxy Shares are no longer subject to the Irrevocable Proxy, the
     certificates evidencing such excess Proxy Shares may have the restrictive
     legend set forth in Section 14.2 removed.

          D.   The Shareholders and the Company believe it to be in their
     respective best interests that the Shareholders be restricted in their
     right to dispose of Shares of the Company now or hereafter owned by any of
     the Shareholders, to protect the Shareholders in the event of certain
     transfers, and to provide for the purchase of the Shares upon the death,
     divorce, disability, termination or bankruptcy of any Shareholder.

          E.   The Shareholders are both officers, directors and employees of
     the Company.

          F.   The Shareholders deem it to be in the best interest of the
     Company and its shareholders to set forth a mechanism to insure the
     continuity of, and provide stability with respect to, the management of the
     Company, both presently and during a transitional period of ten (10) years
     following the death of either one of the Shareholders; and

          G.   The Shareholders desire to enter into an agreement to be
     specifically enforceable against each of them, or the Decedent's Estate and
     their respective Family Members (as defined below), heirs, descendants,
     executors, administrators and other legal representatives, pursuant to
     which (i) they agree to vote their Shares in the manner and for the
     purposes specified herein, and (ii) Trahan shall, for a period of ten (10)
     years from the date of this Agreement, have an
<PAGE>

     Irrevocable Proxy to vote the Proxy Shares that are owned and registered in
     the name of Mooney, in the manner and for the purposes specified herein.

     NOW, THEREFORE, in consideration of the foregoing facts and the mutual
agreements set forth herein, the parties agree as follows:

     1.   Transfer Restriction. During the term of this Agreement, no
          --------------------
Shareholder may transfer, assign, hypothecate or otherwise dispose of any of the
Shares except in accordance with this Agreement, and all certificates evidencing
the Shares shall bear the following legend:

          "These shares are subject to restrictions on transfer contained in a
          Buy-Sell Agreement, a copy of which may be inspected at the principal
          office of the Company."

     2.   Notice of Intent to Transfer. If either Shareholder shall desire to
          ----------------------------
transfer, assign, hypothecate or otherwise dispose of any Shares (excluding the
Excepted Shares as set forth in Section 5), such Shareholder ("Selling
Shareholder") shall give the Company and the other Shareholder ("Remaining
Shareholder") written notice ("Notice") of such proposed disposition ("Offer")
and i) offer to sell such Shares ("Offered Shares") to the Company and, at the
election of the Company, to the Remaining Shareholder, pursuant to the Right-of-
First-Refusal described in Section 3, and ii) offer Co-Sale Rights to the
Remaining Shareholder as described in Section 4. Such Notice shall also set
forth the intended third party transferee ("Transferee"), and a copy of the
written instrument or agreement involved.

     3.   Right-of-First-Refusal. The Company shall have the initial option to
          ----------------------
purchase any or all of the Offered Shares on the terms and conditions presented
in the Offer. The Remaining Shareholder shall then have the option to purchase
any or all of the Offered Shares remaining, (i.e. those not purchased by the
Company), also pursuant to the terms and conditions presented in the Offer. The
Company shall notify the Remaining Shareholder of the number of shares available
for purchase by the Remaining Shareholder within fifteen (15) days of the
Company's receipt of the Notice. The Remaining Shareholder will then have ten
(10) days within which to exercise his option. The Company and/or the Remaining
Shareholder shall have the option for a period of twenty-five (25) days from the
date of the Company's receipt of the Notice to accept such terms and conditions
of the Offer.

          3.1  Acceptance. If the Offer is accepted in writing prior to
expiration of the twenty-five (25) day period described in Section 3, the price
for the Offered Shares as set forth in the Offer may be paid within thirty (30)
days of acceptance.

          3.2  Rejection. If the Offer has not been accepted in writing prior to
expiration of the twenty-five (25) day period, the Selling Shareholder shall
have the right for a period of sixty (60) days thereafter to dispose of all (but
not less than all) of the Offered Shares in accordance with the terms of the
Offer. If not disposed of by the end of such second sixty (60) day period, the
Offered Shares shall again become subject to the restrictions of this Agreement.

     4.   Co-Sale Rights. In addition to the Right-of-First-Refusal, the Selling
          --------------
Shareholder hereby agrees, in the event of any sale of Shares owned by him to a
third party purchaser, to promptly give Notice to the Remaining Shareholder at
least twenty-five (25) days prior to the closing of such sale. The Notice shall
describe in reasonable detail the proposed sale including, without limitation,
the number of Shares to be sold, the nature of such sale, the consideration to
be paid, and the name and address of each prospective purchaser or transferee.
Remaining Shareholder shall have the right, but not the obligation, to sell a
number of Shares owned by him up to an equal number of Shares being sold by the
Selling Shareholder. To the extent the Remaining Shareholder exercises such
right of co-sale, the
<PAGE>

number of Shares that the Selling Shareholder may sell in the transaction shall
be correspondingly reduced. The co-sale rights of the Remaining Shareholder
shall be automatic and not subject to the election or option of the Company. A
decision by the Remaining Shareholder to sell Shares pursuant to this Section 4
shall be an independent decision to sell by the Remaining Shareholder and shall
not be deemed a joint decision by the Shareholders to sell their Shares.

          4.1  Acceptance of Co-Sale. At any time within twenty-five (25) days
after the date of the Notice, the Remaining Shareholder may accept the Offer for
up to such number of Shares as is determined under Section 4 by furnishing to
the Selling Shareholder written notice and an undertaking to deliver, at least
three (3) days prior to the consummation of the sale of the Shares to the
Transferee, the certificates representing the Remaining Shareholder's Shares to
be transferred pursuant to the Offer (the "Included Shares") together with a
limited power of attorney authorizing the Selling Shareholder to transfer the
Included Shares pursuant to the terms of such Offer. If Remaining Shareholder
does not accept the Offer within twenty-five (25) days, the Selling Shareholder
shall have sixty (60) days in which to sell to the Transferee not more than the
number of Shares covered by the Offer on terms not more favorable to the Selling
Shareholder than were set forth in the Notice.

          4.2  Consummation of Sale. At the time of consummation of the sale of
the Included Shares to the Transferee, the Selling Shareholder shall cause to be
remitted to the Remaining Shareholder a certified check from such Transferee for
the total sale price of the respective Included Shares sold pursuant thereto,
and the Selling Shareholder shall furnish, or shall cause to be furnished, such
sale agreement and the terms thereof as may be reasonably requested. If, and to
the extent that the end of sixty (60) days following the date on which the
Notice was given the Selling Shareholder has not completed the sale of the
Included Shares in accordance with the terms of the Offer, it shall return to
the Remaining Shareholder all certificates representing the respective Included
Shares that such Remaining Shareholder transmitted pursuant to the terms hereof,
and all the restrictions on sale, transfer or assignment contained in this
Agreement with respect to Shares owned by the Selling Shareholder shall again be
in effect.

     5.   Excepted Shares. This Agreement shall not restrict the sale of
          ---------------
"Excepted Shares" by either of the Shareholders. "Excepted Shares" shall mean:

          a.   Shares sold in brokerage transactions pursuant to Rule 144,
     provided that five (5) days advance notice of the sale has been given to
     the other Shareholder; and

          b.   Shares sold in a secondary offering registered under the
     Securities Act of 1933, provided that each Shareholder has been afforded an
                             -------- ----
     opportunity to participate equally in such offering.

          c.   Up to an aggregate 150,000 Shares transferred either by gift to
     charitable or religious institutions or to family members directly or
     through trusts for estate planning purposes.

     6.   Death of a Shareholder. Upon the death of any Shareholder, the Company
          ----------------------
and, to the extent not exercised by the Company, the surviving Shareholder
("Surviving Shareholder") shall have the option to purchase and redeem, pursuant
to Sections 6.1 and 6.2 (the "Purchase Provisions") all of the decedent's
Shares. The Company and/or the Surviving Shareholder must exercise the options
to purchase and redeem within ninety (90) days of the date of knowledge of
decedent's death, or as soon thereafter as decedent's estate shall be legally
entitled to effect the transaction; provided, however, that the Right of First
                                    --------  -------
Refusal under Section 3, the Company's Co-Sale Rights under Section 4 and Rule
144 sale advance notice provision under Section 5(a) shall remain in effect and
be applicable to the Shares of a deceased Shareholder so long as they are held
by a "Family Member" of a deceased Shareholder,
<PAGE>

during the term of this Agreement. "Family Member" shall mean a member of a
deceased Shareholder's family by blood or marriage (including without
limitation, parents, spouse, siblings, children, grandchildren and in-laws).

          6.1  Purchase Price. The per share "Purchase Price" shall be the
closing price per share of the Company's stock as listed on the American Stock
Exchange or such other public market upon which the Company's stock is primarily
traded, on the day prior to the date of the triggering death, divorce,
disability, termination or bankruptcy.

          6.2  Acceptance. The price for the available Shares may be paid in
cash or by delivery of cash in the amount of 25% of the Purchase Price therefor
and an unsecured promissory note for the balance executed by the Company or the
Surviving or Other Shareholder, as appropriate. Such note shall provide for (1)
interest at the rate of 10% per annum; (2) three equal annual installments of
principal, together with accrued interest; and (3) acceleration upon any sale,
exchange or other disposition of any of the Shares or the sale, outside the
ordinary course of business, of more than 50% (by value) of the assets of the
Company or any merger or reverse merger resulting in a change of control of the
Company. No such disposition of the Shares or of the assets of the Company, or
merger, may be consummated prior to the payment of such note. The term "Other
Shareholder" as used herein shall refer to the Shareholder with the right to
purchase Shares pursuant to Sections 7 through 10 hereof.

          6.3  Purchase by Shareholders. To the extent, if any, that the Company
is legally unable to comply with its obligations under this Section 6, the
Surviving Shareholder may effect such purchase in accordance with the terms of
the Purchase Provisions. The Company shall notify the Surviving Shareholder,
within sixty (60) days of its knowledge of the decedent's death, of the number
of shares available for purchase by the Surviving Shareholder. The Surviving
Shareholder will then have thirty (30) days within which to exercise his option.

          6.4  Costs. All costs of obtaining appropriate court orders and tax
clearances incident to a purchase under this Section 6 shall be borne by
decedent's estate.

          6.5  Decedent's Estate. As used herein, "decedent's estate" shall mean
and include (1) the deceased Shareholder's duly appointed executor, executrix,
administrator or administratrix; (2) the deceased Shareholder's surviving joint
tenant as owner of the Shares; (3) any other person who, by reason of community
property interest or otherwise, acquires any interest in any of the Shares by
reason of such death; and (4) to the extent applicable, any inter vivos or
testamentary trust.

     7.   Death or Divorce of Spouse of Shareholder. In the event the death of
          -----------------------------------------
the spouse of a Shareholder, or the marital dissolution or legal separation of a
Shareholder and his spouse, results in the passing of any interest in the Shares
to someone other than such Shareholder or a trust for which such Shareholder is
a beneficiary, or results in the acquisition of any Shares by such spouse, such
Shareholder shall have the option to purchase from such third person or spouse,
or the legal representative of such spouse's estate, any or all of the Shares so
passing, in accordance with the Purchase Provisions. The option of such
Shareholder to purchase shall be exercisable within thirty (30) days after such
Shareholder receives written evidence of the death of his spouse or of the entry
of the final or preliminary decree of dissolution or legal separation which
purports to transfer rights in the Shares, and shall be exercised by delivering
written notice of such exercise within such thirty (30) day period to such third
person or his spouse or the legal representative of such spouse's estate.

          7.1  Option to the Company. If such Shareholder does not exercise his
option to purchase all of the Shares as set forth above, he shall notify the
Company within such thirty (30) day period. For a period of fifteen (15) days
following receipt of such notice (or for a period of fifteen (15) days following
the failure or termination of any unsuccessful attempt to exercise), the Company
shall
<PAGE>

have the option to purchase any of the Shares not purchased by such Shareholder
in accordance with the Purchase Provisions, exercisable by delivery of written
notice of such exercise to such third person, such spouse, or the legal
representative of such spouse's estate. The right of the Company to purchase the
Shares shall not be conditioned upon its receipt of notice from such Shareholder
as provided in this Section 7.1.

          7.2  Option to Other Shareholder. If any of the Shares are not
purchased by the Company, the Company shall notify the Shareholder who did not
have an option to purchase pursuant to Section 7.1 in writing within its fifteen
(15) day option period. For a period of fifteen (15) days following receipt of
such notice from the Company (it being understood that their option shall not be
conditioned upon delivery of such notice), such Shareholder shall have the
option to purchase any of the Shares not purchased by the Company in accordance
with the Purchase Provisions, exercisable by delivery of written notice of such
exercise to such third person, spouse, or legal representative of the spouse's
estate.

     8.   Shareholder's Disability. If a Shareholder then employed on a full-
          ------------------------
time basis by the Company is rendered permanently disabled (as defined below),
the Company may purchase all of the Shares owned by such Shareholder at the time
of his disability in accordance with the Purchase Provisions. If the Company
elects not to purchase any or all of the Shares, the Other Shareholder may
purchase any or all of such Shares in accordance with the Purchase Provisions.

          8.1  Permanent Disability. For the purposes of this Section 8 the
terms "permanently disabled" and "permanent disability" shall mean any physical
or mental disability, or combination thereof, causing a Shareholder to be unable
to substantially perform his normal duties as an employee of the Company and
which is (i) determined to be a total disability by the disability insurer then
insuring the Shareholder, or (ii) if no such insurance is then in effect, is
verifiable by medical findings and appears reasonably certain to continue for at
least one year without substantial improvement. In the case of (ii) in the
preceding sentence, the disability shall be established by the opinion of a
physician chosen by the Company and the Other Shareholder.

     9.   Termination of Employment During Lifetime. If any Shareholder shall
          -----------------------------------------
cease to be an employee of the Company for any reason other than death or
permanent disability ("Terminated Shareholder"), the Company, for thirty (30)
days following the termination of his employment, shall have the option to
purchase the Shares owned by such Terminated Shareholder in accordance with the
Purchase Provisions. The Company's option shall be exercised by delivering to
the Terminated Shareholder, within the thirty (30) day option period, a written
notice of election to purchase the Shares. Such option shall not be exercised as
to less than all of the Shares unless the Other Shareholder exercises his option
(as provided in Section 9.1 below) to purchase, concurrently with the purchase
of any Shares by the Company, any Shares not purchased by the Company.

          9.1  Option to Other Shareholder. If the Company's option is not
exercised in full, the secretary of the Company shall give, within the thirty
(30) day option period, written notice of that fact by registered or certified
mail to the Other Shareholder, who shall then have the option to purchase the
Shares at the same terms and price as applicable to the Company. Within twenty
(20) days after the mailing of such notice, the Other Shareholder shall deliver
to the secretary a written election to purchase the Shares or a specified number
thereof.

     10.  Bankruptcy. All proposed judicial transfers and sale of Shares by
          ----------
order of any court in bankruptcy ("Order") shall be subject to the terms of this
Agreement. In the event a sale or transfer is proposed pursuant to an Order, all
of the terms of the preceding Sections shall apply with the following
modification. Instead of a Notice being delivered to the secretary of the
Company, a copy of the Order shall be delivered to the secretary of the Company
by the proposed transferee which shall state the name
<PAGE>

and address of the proposed transferee and specify the number of Shares to be
sold, the price per share and the terms of proposed transfer. For all other
purposes of this Section 10, the receipt of the Order shall be treated as the
receipt of a Notice. All proposed transfers pursuant to an Order which do not
set forth a purchase price capable of valuation which would allow the Company
and the Other Shareholder to exercise its or his option hereunder are expressly
prohibited.

          10.1 Transfers Pursuant to Transfer Order. If the Shares are not
purchased by the Company or Other Shareholder within the time periods and upon
the terms specified above, the Selling Shareholder may transfer the Shares
covered by the Order at any time within ninety (90) days from the date of the
Order to the person and according to the terms and price specified in the Order.
Such person will receive and hold the Offered Shares subject to all of the
provisions and restrictions herein contained and, by the receipt of the Shares,
shall be deemed to consent to the terms of and be a party to this Agreement;
provided, however, if the Company elects, such person shall, as a condition to
the valid transfer of the Shares to him, execute appropriate instruments to
confirm his obligation hereunder with respect to the Shares. Any transfer of the
Shares after the end of the ninety (90) day period or any change in the parties,
terms or price from those set forth in the Order shall require a new notice of
intention to transfer and shall give rise to the options provided in this
Section 10.

     11.  Vote of the Interested Shareholder. The Shareholder whose shares
          ----------------------------------
become available through an Offer, death, divorce, disability, termination or
bankruptcy (the "Interested Shareholder"), or such Interested Shareholder's
heirs and assigns, shall abstain from voting either as a director or shareholder
of the Company, and the available or Offered Shares shall not be voted, in any
vote taken regarding whether or not the Company shall exercise its options to
purchase such Shares.

     12.  Administrative Approvals. The right of the Company to exercise the
          ------------------------
option to purchase the Shares is subject to the restrictions governing the right
of a corporation to purchase its own stock contained in the Delaware General
Corporate law, and other pertinent government restrictions as are now or may
hereafter become effective. The Company shall apply for and use its best efforts
to obtain all governmental and administrative approvals required in connection
with the purchase and sale of any Shares under this Agreement. The Shareholders
shall cooperate in obtaining such approvals and shall execute any and all
documents that may be required in connection with the approvals.

     13.  Voting Agreement. As a reasonable mechanism to insure the continued
          ----------------
continuity of, and to provide stability with respect to, the management of the
Company, each of the Shareholders agrees, while both Shareholders shall be
living, to vote his Shares at all elections of directors in favor of the
election of each Shareholder as a director of the Company.

     14.  Irrevocable Proxy.
          -----------------

          14.1 In order to ensure the voting of the Shares with the terms of
this Agreement, Mooney agrees to execute an Irrevocable Proxy, simultaneously
with the execution of this Agreement, substantially in the form of the attached
Exhibit A granting to Trahan for a period of ten (10) years from the date of
this Agreement, to vote, or to execute and deliver shareholder written consents,
in respect of the Proxy Shares now beneficially owned and registered in the name
of Mooney, or as a result of a transfer after the date hereof by reason of
Mooney's death, registered in the name of Mooney's estate, Family Members or
heirs. The Proxy Shares shall be allocated pro rata to Mooney's Family Members,
heirs or estate in the proportion that the Proxy Shares are distributed and held
among such persons pursuant to the laws of descent and distribution unless
provided otherwise in Mooney's will. It is understood and agreed that the
Irrevocable Proxy relates to voting for the election of directors of the Company
and on all other corporate matters which may from time to time be submitted to
the shareholders of the Company for a vote, as set forth in the Irrevocable
Proxy. It is further understood and agreed that on and as of each record date,
the Inspector shall determine the number of Proxy Shares
<PAGE>

subject to the Irrevocable Proxy, which determination shall be final and
conclusive and that in the event the Inspector determines that some or all of
the Proxy Shares are no longer subject to the Irrevocable Proxy, then all of the
certificates evidencing the excess Proxy Shares may have the restrictive legend
referred to in Section 14.2 removed.

          14.2 The initial Proxy Shares and any Proxy Shares issued to a
subsequent distributee shall be evidenced by a single certificate for each
distributee, which shall bear a legend, in addition to the legend set forth in
Section 1 of this Agreement, substantially as follows:

          "These shares are subject to a certain Shareholders Buy-Sell
          and Voting Agreement and Irrevocable Proxy coupled with an
          interest in favor of the Proxyholder designated thereon,
          granting to the Proxyholder certain voting rights with
          respect to the Proxy Shares. A copy of the Shareholders Buy-
          Sell and Voting Agreement and Irrevocable Proxy is available
          for inspection at the office of the Corporation."

     The above legend shall also be set forth on any Proxy Share certificate(s)
issued upon any transfer assignment hypothecation or other disposition of the
Proxy Shares, including by the laws of descent and distribution for so long as
such Proxy Shares are subject to the terms of the Irrevocable Proxy.

     15.  Changes in Common Stock. In the event that subsequent to the date of
          -----------------------
this Agreement any shares or other securities (other than any shares or
securities of another corporation issued to the Company's shareholders pursuant
to a plan of merger) are issued on, or in exchange for, any of the Shares held
by the Shareholders by reason of any stock dividend, stock split, consolidation
of shares, reclassification, or consolidation involving the Company, such shares
or securities shall be deemed to be Shares for the purposes of this Agreement.

     16.  Representations of Shareholders. Each Shareholder hereby represents
          -------------------------------
and warrants to the other Shareholder that (a) he owns and has the right to vote
the number of Shares set forth opposite his name and signature below, (b) he has
full power to enter into this Agreement and has not, prior to the date of this
Agreement, executed or delivered any proxy or entered into any other voting
agreement or similar arrangement other than one which has expired or terminated
prior to the date hereof, and (c) he will not take any action inconsistent with
the purposes and provisions of this Agreement.

     17.  Enforceability. Each Shareholder expressly agrees that this Agreement
          --------------
shall be specifically enforceable in any court of competent jurisdiction in
accordance with its terms against each of the parties hereto and their
respective successors, assigns, Family Members, heirs, executors, administrators
and other legal representatives, as the case may be.

     18.  Termination. This Agreement shall terminate upon the earliest to occur
          -----------
of the following: (a) the written agreement of all parties to terminate this
Agreement; (b) the dissolution, bankruptcy or insolvency of the Company; (c) at
such time as only one Shareholder remains, except that the provisions of
Sections 6, 11 and 14 shall continue in effect following the death of a
Shareholder; or (d) August 6, 2009. This Agreement may be extended annually or
from time to time by the Shareholders at any time after August 6, 2000 by the
execution by the Shareholders of an extension agreement (the "Extension
Agreement"), substantially in the form of the attached Exhibit B, extending the
term of the Agreement for an additional one-year term, or longer period so that
the remaining term of the Agreement shall be for a period of 10 years from the
date of each extension period, it being the intent of the parties by entering
into Extension Agreement(s) that this Agreement shall have a perpetual 10-year
term.
<PAGE>

     19.  Arbitration. Any controversy or claim arising out of this Agreement,
          -----------
or any breach of this Agreement, including any controversy or claim as to
arbitrability or rescission, shall be settled by arbitration in accordance with
the commercial arbitration rules of the American Arbitration Association.

          19.1  Location. Arbitration shall be conducted in either Los Angeles
County or Orange County, California or such other location as is mutually
agreeable to all of the parties to this Agreement.

          19.2  Judgment. Any judgment upon the award rendered by the
arbitrators may be entered in any court having jurisdiction thereof. The
arbitrators shall not, under any circumstance, have any authority to award
punitive, exemplary or similar damages.

          19.3  Equitable Remedies. Either party may pursue the remedy of
specific performance of this Agreement, or seek a preliminary or permanent
injunction against the breach of this Agreement or in aid of the exercise of any
power granted hereunder, or any combination thereof, in any court having
jurisdiction thereof without resort to arbitration.

     20.  Notices. All notices, requests, demands and other communications
          -------
permitted or required hereunder shall be in writing, and either (i) delivered in
person, (ii) sent by express mail or other overnight delivery service providing
receipt of delivery, or (iii) sent by telecopy or other facsimile transmission
as follows:

          If to the Company:

          Hi-Shear Technology Corporation
          24225 Garnier Street
          Torrance, CA 90505-5323
          Facsimile: (310) 784-7806

          If to Thomas R. Mooney:

          Hi-Shear Technology Corporation
          24225 Garnier Street
          Torrance, CA 90505-5323
          Facsimile: (310) 784-7806

          If to George Trahan:

          Hi-Shear Technology Corporation
          24225 Garnier Street
          Torrance, CA 90505-5323
          Facsimile: (310) 784-7806

     21.  Miscellaneous. Each Shareholder's will or, if applicable, inter vivos
          -------------
trust, shall contain a direction and authorization to comply with the provisions
of this Agreement and to sell the Shareholder's Shares in accordance with this
Agreement, but the failure of any Shareholder to do so shall not affect the
validity or enforceability of this Agreement. Should any one or more of the
provisions of this Agreement be determined to be illegal or unenforceable, all
other provisions of the Agreement shall be given effect separately from such
provisions, and the other provisions shall not be affected by such illegality or
unenforceability. In any action at law or in equity to enforce any of the
provisions or rights under this Agreement, the unsuccessful party or parties to
such litigation, as determined by the court in a final judgment or decree, shall
pay to the successful party or parties all costs, expenses and reasonable
<PAGE>

attorneys' fees incurred by the successful party or parties (including without
limitation, costs, expenses and fees on any appeals), and if the successful
party or parties recovers judgment in any such action or proceedings, such
costs, expenses and attorneys' fees shall be include as part of the judgment.

          21.1  Binding Agreement. All of the covenants and agreements contained
in this Agreement shall be binding upon, and inure to the benefit of, the
respective parties and their successors, assigns, Family Members, heirs,
executors, administrators and other legal representatives, as the case may be.

          21.2  Entire Agreement. This Agreement constitutes the entire
agreement between the Shareholders with respect to the subject matter hereof,
and supersedes any and all prior and contemporaneous agreements and
understandings of the parties, whether written or oral, with respect thereto.

          21.3  Governing Law. Except with regard to arbitration, which shall be
governed by the provisions of Section 19 above, this Agreement, and the rights
of the parties hereto, shall be governed by and construed and enforced in
accordance with the laws of the State of Delaware, without regard to conflicts
of laws rules and principles.

          21.4  Counterparts. This Agreement may be executed in one or more
counterparts, each of which will be deemed an original but all of which together
shall constitute one and the same instrument.

          21.5  No Waiver. No waivers of any breach of this Agreement extended
by any party hereto to any other party shall be construed as a waiver of any
rights or remedies of any other party hereto or with respect to any subsequent
breach.

          21.6  Number and Gender. Whenever the context of this Agreement shall
so require, the use of the singular number shall include the plural and the use
of any gender shall include all genders.


                           [SIGNATURE PAGE FOLLOWS]
<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                                         HI-SHEAR TECHNOLOGY CORP.


                                         By:  /s/ Linda A. Nespole
                                              -----------------------

                                         Its: Corporate Secretary
                                              -----------------------


/s/ Thomas R. Mooney              2,700,000   Shares
--------------------              ---------
Thomas R. Mooney


/s/ George W. Trahan              2,180,580   Shares
--------------------              ---------
George W. Trahan
<PAGE>

                                SPOUSAL CONSENT

          I acknowledge that I have read the foregoing Shareholders Buy-Sell and
Voting Agreement and Irrevocable Proxy dated as of August 6, 1999 and that I
know its contents.  I am aware that by its provisions, my spouse has agreed to
vote his Shares of the Company, including any such Shares in which I may have
community property interest, in accordance with the terms of said agreement and
to sell all Shares, excluding the Excepted Shares (as defined therein), of the
Company, including my community interest in them.  I hereby approve of the
provisions of the Shareholders Buy-Sell and Voting Agreement and Irrevocable
Proxy, including my spouse's granting of an Irrevocable Proxy to become
effective immediately, and agree that I will not take any action to frustrate
the purpose and intent of, nor challenge the provisions of, the Shareholders
Buy-Sell and Voting Agreement and Irrevocable Proxy.  I also hereby consent to
the sale, approve of the provisions of the Shareholders Buy-Sell and Voting
Agreement and Irrevocable Proxy and agree that I will not bequeath the Shares or
any of them or any interest in them by my will if I predecease my spouse.

DATED: August 6, 1999                             ___________________________
<PAGE>

                                   EXHIBIT A

                          HI-SHEAR TECHNOLOGY CORP.,
                            a Delaware corporation
                               IRREVOCABLE PROXY

          The undersigned Thomas R. Mooney ("Grantor")  agrees to, and hereby
grants to George W. Trahan ("Proxyholder") an Irrevocable Proxy, to become
effective immediately,  pursuant to the provisions of Section 212 of the General
Corporation Law of Delaware to vote, or to execute and deliver written consents
or otherwise act with respect to one-half (1/2) of the excess of the shares of
capital stock beneficially owned by Grantor over the shares of capital stock
beneficially owned by Proxyholder according to the official stock transfer
records of HI-SHEAR TECHNOLOGY CORP. (the "Corporation") on and as of the record
date as determined under Section 213 of the General Corporation Law of Delaware
(the "Proxy Shares") that are owned and registered in the name of Grantor, as
fully, to the same extent and with the same effect as Grantor might or could do
under any applicable laws or regulations governing the rights and powers of
shareholders of a Delaware corporation in connection with all corporate matters
which may be submitted to the shareholders for a vote from time to time,
including but  not limited to (i) all elections of directors of the Corporation,
(ii) proposals to amend the Corporation's Certificate of Incorporation, (iii)
proposals regarding the merger, consolidation, or reorganization of the
Corporation, or a sale of all or substantially all of the Corporation's assets,
as provided in that certain Shareholders Buy-Sell and Voting Agreement and
Irrevocable Proxy, dated as of August 6, 1999 (the "Agreement"), among the
Grantor and Proxyholder and the Corporation.  Grantor and Proxyholder
acknowledge and agree that on and as of each record date, the Inspector of
Elections shall determine the number of Proxy Shares subject to the Irrevocable
Proxy, which determination shall be final and conclusive.  This Irrevocable
Proxy shall become immediately effective and may be exercised by Proxyholder,
his estate, Family Members and other heirs for a period of ten (10) years from
the date hereof, and for such longer period as this proxy shall be extended by
mutual written agreement between the parties hereto (not to exceed a term of 10
years from the date of any such  extension), unless sooner terminated in
accordance with the provisions of the Agreement.

          This Irrevocable Proxy shall be transferable upon the death of
Proxyholder to Proxyholder's estate and thereafter to such Family Member or
other heir of Proxyholder who then owns the majority of Proxyholder's Shares
distributed by the laws of descent and distribution.   This Irrevocable Proxy
shall expire and terminate automatically by its terms if Proxyholder, his
estate,  Family Members, and other heirs, collectively, at any time, own
beneficially and of record less than 500,000 shares of the Corporation's common
stock.

          This Irrevocable Proxy is given as a condition of the Agreement and as
such is coupled with an interest and is irrevocable, and further by virtue of
Grantor's and Proxyholder's ownership of Shares and their positions with the
Corporation.

          All defined terms not defined herein, shall have the meaning assigned
in the Agreement.

          Grantor  affirms that  the giving of this Irrevocable Proxy is in the
best interest of the Corporation in order to provide "voting parity" between
Grantor and Proxyholder, and to ensure the continuity of stability with respect
to the management of the Corporation during the term of the Agreement, including
a transitional period after the death of either or both of Grantor and
Proxyholder.
<PAGE>

          THIS PROXY SHALL REMAIN IN FULL FORCE AND EFFECT AND BE ENFORCEABLE
AGAINST ANY DONEE, TRANSFEREE, OR ASSIGNEE OF THE SHARES, INCLUDING, WITHOUT
LIMITATION, THE UNDERSIGNED'S FAMILY MEMBERS (AS DEFINED IN THE AGREEMENT),
OTHER HEIRS, AND HIS ESTATE.

Dated as of August 6, 1999.



/s/ Margery Stratemeyer                   /s/ Thomas R. Mooney
-------------------------                 ----------------------
WITNESS


/s/ Lisa Howiler
-------------------------
WITNESS
<PAGE>

                                SPOUSAL CONSENT

          I acknowledge that I have read the foregoing Shareholders Buy-Sell and
Voting Agreement and Irrevocable Proxy dated as of August 6, 1999 and that I
know its contents.  I am aware that by its provisions, my spouse has agreed to
vote his Shares of the Company, including any such Shares in which I may have
community property interest, in accordance with the terms of said agreement.  I
hereby approve of the provisions of the Shareholders Buy-Sell and Voting
Agreement and Irrevocable Proxy, including my spouse's granting of an
Irrevocable Proxy to become effective upon his death, and agree that I will not
take any action to frustrate the purpose and intent of, nor challenge the
provisions of, the Shareholders Buy-Sell and Voting Agreement and Irrevocable
Proxy.

DATED: August 6, 1999                    _____________________________
<PAGE>

                                   EXHIBIT B


                           HI-SHEAR TECHNOLOGY CORP.

                              EXTENSION AGREEMENT

     THIS EXTENSION AGREEMENT ("Agreement") is entered into as of ______, 2___,
by and among HI-SHEAR TECHNOLOGY CORP., a Delaware corporation (the "Company"),
and Thomas R. Mooney ("Mooney") and George W. Trahan ("Trahan") (collectively,
the "Shareholders"), with respect to the following facts:

          A.   The Company and the Shareholders are parties to that certain
     Shareholders Buy-Sell and Voting Agreement and Irrevocable Proxy dated
     August 6, 1999 (the "Shareholders Agreement").

          B.   Mooney is the Grantor of that certain Irrevocable Proxy attached
     as Exhibit A to the Agreement (the "Irrevocable Proxy").

          C.   The Company and the Shareholders believe it to be in their
     respective best interests that each of the Shareholders Agreement and the
     Irrevocable Proxy (collectively, the "Agreements") have a perpetual ten-
     year term.

     NOW, THEREFORE, in consideration of the foregoing facts and the mutual
agreements set forth herein, the parties agree as follows:

     1.   Extension of Agreements. The term of each of the Shareholders
          -----------------------
Agreement and the Irrevocable Proxy is extended until _______, 2____, which date
is ten years from the date of the execution of this Agreement.

     2.   Replacement of Irrevocable Proxy. Mooney shall execute and deliver to
          --------------------------------
Trahan a new Irrevocable Proxy in the form of Exhibit A attached hereto, to
reflect the extended term of the Irrevocable Proxy set forth in paragraph 1
above, and which shall replace, cancel and revoke all prior Irrevocable Proxies
executed by Grantor.


                           [SIGNATURE PAGE FOLLOWS]
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Extension Agreement as
of the date first above written.

                              HI-SHEAR TECHNOLOGY CORP.


                              By:_____________________________

                              Its:____________________________


                              ________________________________
                              Thomas R. Mooney


                              ________________________________
                              George W. Trahan