EXHIBIT 10.6.3


U.S.  BANK CREDIT FACILITY

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                                                               PROMISSORY NOTE
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     PRINCIPAL          LOAN DATE        MATURITY       LOAN NO.              COLLATERAL        ACCOUNT        OFFICER
   <S>                 <C>              <C>              <C>         <C>          <C>          <C>              <C>       <C>
   $5,500,000.00       03-23-2000       11-01-2000       2784-       CALL         070          1105510939       DJS64     INITIALS
-------------------- ---------------- --------------- ------------- -------- -------------- ----------------- ----------- ----------

                                REFERENCES IN THE SHADED AREA ARE FOR LENDER'S USE ONLY AND DO NOT LIMIT THE
                                       APPLICABILITY OF THIS DOCUMENT TO ANY PARTICULAR LOAN OR ITEM
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</TABLE>

BORROWER: HI-SHEAR TECHNOLOGY CORP.     LENDER: U.S. BANK NATIONAL ASSOCIATION
          24225 GARNIER ST.                     4100 NEWPORT PLACE, SUITE 120
          TORRANCE, CA  90505                   NEWPORT BEACH, CA  92660

================================================================================

PRINCIPAL AMOUNT:  $5,500,000.00                   DATE OF NOTE:  MARCH 23, 2000

PROMISE TO PAY. HI-SHEAR TECHNOLOGY CORP. ("Borrower") promises to pay to U.S.
Bank National Association ("Lender"), or order, in lawful money of the United
States of America, the principal amount of Five Million Five Hundred Thousand &
00/100 Dollars ($5,500,000.00) or so much as may be outstanding, together with
interest on the unpaid outstanding principal balance of each advance. Interest
shall be calculated from the date of each advance until repayment of each
advance.

PAYMENT. Borrower will pay this loan on demand, or if no demand is made, in one
payment of all outstanding principal plus all accrued unpaid interest on
November 1, 2000. In addition, Borrower will pay regular monthly payments of
accrued unpaid interest beginning April 1, 2000, and all subsequent interest
payments are due on the same day of each month after that. The annual interest
on this Note is computed on a 365/360 basis; that is, by applying the ratio of
the annual interest rate over a year of 360 days, multiplied by the outstanding
principal balance, multiplied by the actual number of days the principal balance
is outstanding. Borrower will pay Lender at Lender's address shown above or at
such other place as Lender may designate in writing.

VARIABLE INTEREST RATE. The interest rate on this Note is subject to change from
time to time based on changes in an independent index which is the Wall Street
Journal Prime Rate. This is the Prime Rate as published in the West Coast
edition of The Wall Street Journal "Money Rates" column (the "Index"). The Index
is not necessarily the lowest rate charged by Lender on its loans. If the Index
becomes unavailable during the term of this loan, Lender may designate a
substitute index after notice to Borrower. Lender will tell Borrower the current
Index rate upon Borrower's request. Borrower understands that Lender may make
loans based on other rates as well. The interest rate change will not occur more
often than each day. The interest rate to be applied to the unpaid principal
balance of this Note will be at a rate of 0.500 percentage points over the
Index. NOTICE: Under no circumstances will the interest rate on this Note be
more than the maximum rate allowed by applicable law.

PREPAYMENT. Borrower agrees that all loan fees and other prepaid finance charges
are earned fully as of the date of the loan and will not be subject to refund
upon early payment (whether voluntary or as a result of default), except as
otherwise required by law.

Except for the foregoing, Borrower may pay without penalty all or a portion of
the amount owed earlier than it is due. Early payments will not, unless agreed
to by Lender in writing, relieve Borrower of Borrower's obligation to continue
to make payments of accrued unpaid interest. Rather, they will reduce the
principal balance due.

DEFAULT. Borrower will be in default if any of the following happens: (a)
Borrower fails to make any payment when due. (b) Borrower breaks any promise
Borrower has made to Lender, or Borrower fails to comply with or to perform when
due any other term, obligation, covenant, or condition contained in this Note or
any agreement related to this Note, or in any other agreement or loan Borrower
has with Lender. (c) Borrower defaults under any loan, extension of credit,
security agreement, purchase or sales agreement, or any other agreement, in

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favor of any other creditor or person that may materially affect any of
Borrower's property or Borrower's ability to repay this Note or perform
Borrower's obligations under this Note or any of the Related Documents. (d) Any
representation or statement made or furnished to Lender by Borrower or on
Borrower's behalf is false or misleading in any material respect either now or
at the time made or furnished. (e) Borrower becomes insolvent, a receiver is
appointed for any part of Borrower's property, Borrower makes an assignment for
the benefit of creditors, or any proceeding is commenced either by Borrower or
against Borrower under any bankruptcy or insolvency laws. (f) Borrower is in
default under any other note, security agreement, lease agreement or lease
schedule, loan agreement or other agreement, whether now existing or hereafter
made, between Borrower and U.S. Bancorp or any direct or indirect subsidiary of
U.S. Bancorp. (g) Any creditor tries to take any of Borrower's property on or in
which Lender has a lien or security interest. This includes a garnishment of any
of Borrower's accounts with Lender. (h) Any guarantor dies or any of the other
events described in this default section occurs with respect to any guarantor of
this Note. (i) A material adverse change occurs in Borrower's financial
condition, or Lender believes the prospect of payment or performance of the
indebtedness is impaired. (j) Lender in good faith deems itself insecure.

LENDER'S RIGHTS. Upon default, Lender may declare the entire unpaid principal
balance on this Note and all accrued unpaid interest immediately due, without
notice, and then Borrower will pay that amount. Upon Borrower's failure to pay
all amounts declared due pursuant to this section, including failure to pay upon
final maturity, Lender, at its option, may also, if permitted under applicable
law, increase the variable interest rate on this Note to 5.500 percentage points
over the Index. Lender may hire or pay someone else to help collect this Note if
Borrower does not pay. Borrower also will pay Lender that amount. This includes,
subject to any limits under applicable law, Lender's attorneys' fees and
Lender's legal expenses whether or not there is a lawsuit, including attorneys'
fees and legal expenses for bankruptcy proceedings (including efforts to modify
or vacate any automatic stay or injunction), appeals, and any anticipated
post-judgment collection services. Borrower also will pay any court costs, in
addition to all other sums provided by law. This Note has been delivered to
Lender and accepted by Lender in the State of California. If there is a lawsuit,
Borrower agrees upon Lender's request to submit to the jurisdiction of the
courts of Sacramento County, the State of California. Subject to the provisions
of arbitration, this Note shall be governed by and construed in accordance with
the laws of the State of California.

RIGHT OF SETOFF. Borrower grants to Lender a contractual security interest in,
and hereby assigns, conveys, delivers, pledges, and transfers to Lender all
Borrower's right, title and interest in and to, Borrower's accounts with Lender
(whether check, savings, or some other account), including without limitation
all accounts held jointly with someone else and all accounts Borrower may open
in the future, excluding however all IRA and Keogh accounts, and all trust
accounts for which the grant of a security interest would be prohibited by law.
Borrower authorizes Lender, to the extent permitted by applicable law, to charge
or setoff all sums owing on this Note against any and all such accounts.

LINE OF CREDIT. This Note evidences a revolving line of credit. Advances under
this Note may be requested either orally or in writing by Borrower or as
provided in this paragraph. Lender may, but need not, require that all oral
requests be confirmed in writing. All communications, instructions, or
directions by telephone or otherwise to Lender are to be directed to Lender's
office shown above. ADVANCES SHALL BE RESTRICTED TO A MAXIMUM OF $5,100,000
UNTIL IT IS CONFIRMED THAT THE BORROWER HAS LARGELY MET ITS FISCAL YEAR MAY 31,
2000 PROJECTIONS. UPON ADEQUATE VALIDATION, THE FULL LINE OF $5,500,000 WILL BE
AVAILABLE. Borrower agrees to be liable for all sums either: (a) advanced in
accordance with the instructions of an authorized person or (b) credited to any
of Borrower's accounts with Lender. The unpaid principal balance owing on this
Note at any time may be evidenced by endorsements on this Note or by Lender's
internal records, including daily computer print-outs. Lender will have no
obligation to advance funds under this Note if: (a) Borrower or any guarantor is
in default under the terms of this Note or any agreement that Borrower or any
guarantor has with Lender, including any agreement made in connection with the
signing of this Note; (b) Borrower or any guarantor ceases doing business or is
insolvent; (c) any guarantor seeks, claims or otherwise attempts to limit,
modify or revoke such guarantor's guarantee of this Note or any other loan with
Lender; (d) Borrower has applied funds provided pursuant to this Note for
purposes other than those authorized by Lender; or (e) Lender in good faith
deems itself insecure under this Note or any other agreement between Lender and
Borrower.

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ARBITRATION. Lender and Borrower agree that all disputes, claims and
controversies between them, whether individual, joint, or class in nature,
arising from this Note or otherwise, including without limitation contract and
tort disputes, shall be arbitrated pursuant to the Rules of the American
Arbitration Association, upon request of either party. No act to take or dispose
of any collateral securing this Note shall constitute a waiver of this
arbitration agreement or be prohibited by this arbitration agreement. This
includes, without limitation, obtaining injunctive relief or a temporary
restraining order; invoking a power of sale under any deed of trust or mortgage;
obtaining a writ of attachment or imposition of a receiver; or exercising any
rights relating to personal property, including taking or disposing of such
property with or without judicial process pursuant to Article 9 of the Uniform
Commercial Code. Any disputes, claims, or controversies concerning the
lawfulness or reasonableness of any act, or exercise of any right, concerning
any collateral securing this Note, including any claim to rescind, reform, or
otherwise modify any agreement relating to the collateral securing this Note,
shall also be arbitrated, provided however that no arbitrator shall have the
right or the power to enjoin or restrain any act of any party. Lender and
Borrower agree that in the event of an action for judicial foreclosure pursuant
to California Code of Civil Procedure Section 726, or any similar provision in
any other state, the commencement of such an action will not constitute a waiver
of the right to arbitrate and the court shall refer to arbitration as much as
such action, including counterclaims, as lawfully may be referred to
arbitration. Judgment upon any award rendered by any arbitrator may be entered
in any count having jurisdiction. Nothing in this Note shall preclude any party
from seeking equitable relief from a court of competent jurisdiction. This
statue of limitations, estoppel, waiver, laches, and similar doctrines which
would otherwise be applicable in an action brought by a party shall be
applicable in any arbitration proceeding, and the commencement of an arbitration
proceeding shall be deemed the commencement of an action for these purposes. The
Federal Arbitration Act shall apply to the construction, interpretation, and
enforcement of this arbitration provision.

LATE CHARGE. If a payment is 15 days or more past due, Borrower will be charge a
late charge of 5% of the delinquent payment.

YEAR 2000.
Borrower has reviewed and assessed its business operations and computer systems
and applications to address the "year 2000 problem" (that is, that computer
applications and equipment used by Borrower, directly or indirectly through
third parties, may have been or may be unable to properly perform date-sensitive
functions before, during and after January 1, 2000). Borrower represents and
warrants that the year 2000 problem has not resulted in and will not result in a
material adverse change in Borrower's business condition (financial or
otherwise), operations, properties or prospects or ability to repay Lender.
Borrower agrees that this representation and warranty will be true and correct
on and shall be deemed made by Borrower on each date Borrower requests any
advance under this Agreement or Note or delivers any information to Lender.
Borrower will promptly deliver to Lender such information relating to this
representation and warranty as Lender requests from time to time.

PRIOR NOTE. RENEWAL AND EXTENSION. This Note is given in renewal and extension
and not in novation of the following described indebtedness: That certain
Promissory Note dated NOVEMBER 01, 1996, in the amount of $3,500,000.00 executed
by Borrower payable to Lender. It is further agreed that all liens and security
interest securing said indebtedness are hereby renewed and extended to secure
the Note and all renewals, extensions and modifications thereof.

GENERAL PROVISIONS. This Note is payable on demand. The inclusion of specific
default provisions or rights of Lender shall not preclude Lender's right to
declare payment of this Note on its demand. Lender may delay or forgo enforcing
any of its right or remedies under this Note without losing them. Borrower and
any other person who signs, guarantees or endorses this Note, to the extent
allowed by law, waive any applicable statute of limitations, presentment, demand
for payment, protest and notice of dishonor. Upon any change in the terms of
this Note, and unless otherwise expressly stated in writing, no party who signs
this Note, whether as maker, guarantor, accommodation maker or endorser, shall
be released from liability. All such parties agree that Lender may renew or
extend (repeatedly and for any length of time) this loan, or release any party
or guarantor or collateral; or impair, fail to realize upon or perfect Lender's
security interest in the collateral; and take any other action deemed necessary
by Lender without the consent of or notice to anyone. All such parties also
agree that Lender may modify this loan without consent of or notice to anyone
other than the party with whom the modification is made.

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PRIOR TO SIGNING THIS NOTE, BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE, INCLUDING THE VARIABLE INTEREST RATE PROVISIONS. BORROWER AGREES TO
THE TERMS OF THE NOTE AND ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THE NOTE.

BORROWER:

Hi-Shear Technology Corporation

By:  /S/ GEORGE W. TRAHAN                         By: /S/ THOMAS R. MOONEY
     -------------------------------                  --------------------------
     GEORGE TRAHAN, PRESIDENT/CEO/CO-CHAIRMAN         THOMAS MOONEY, CO-CHAIRMAN

LENDER:

U.S. Bank National Association


By   /S/ D. J. SANDFORD
     -------------------------------
     Authorized Officer


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