<PAGE>
                                                                     Exhibit 4.2


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                          FIRST SUPPLEMENTAL INDENTURE

                            Dated as of June 19, 2002

                                     between

                                KENNAMETAL INC.,

                                    AS ISSUER

                                       and

                          BANK ONE TRUST COMPANY, N.A.,

                                   AS TRUSTEE

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<PAGE>



                                TABLE OF CONTENTS

                                                                           PAGE

ARTICLE I  DEFINITIONS........................................................1

         SECTION 1.1.   Definition of Terms...................................1

ARTICLE II  GENERAL TERMS AND CONDITIONS OF THE NOTES.........................4

         SECTION 2.1.   Designation and Principal Amount......................4

         SECTION 2.2.   Maturity..............................................5

         SECTION 2.3.   Form and Payment......................................5

         SECTION 2.4.   Interest..............................................6

ARTICLE III  REDEMPTION OF THE NOTES..........................................6

         SECTION 3.1.   Optional Redemption...................................6

         SECTION 3.2.   No Sinking Fund.......................................7

ARTICLE IV  COVENANTS.........................................................7

         SECTION 4.1.   Amendments to Article 10 of the Indenture.............7

ARTICLE V  CONSOLIDATION, MERGER, LEASE, SALE OR TRANSFER.....................8

         SECTION 5.1.   Amendments to Article 8 of the Indenture..............8

ARTICLE VI  FORM OF NOTES.....................................................8

         SECTION 6.1.   Form of Notes.........................................8

ARTICLE VII  ORIGINAL ISSUE OF NOTES..........................................9

         SECTION 7.1.   Original Issue of Notes...............................9

ARTICLE VIII  MISCELLANEOUS...................................................9

         SECTION 8.1.   Ratification of Indenture.............................9

         SECTION 8.2.   Trustee Not Responsible for Recitals..................9

         SECTION 8.3.   Governing Law.........................................9

         SECTION 8.4.   Severability..........................................9

         SECTION 8.5.   Counterparts.........................................10

EXHIBITS

Exhibit A       Form of Senior Notes


<PAGE>


                  FIRST SUPPLEMENTAL INDENTURE, dated as of June 19, 2002 (the
"First Supplemental Indenture"), between KENNAMETAL INC., a corporation duly
organized and existing under the laws of the Commonwealth of Pennsylvania (the
"Company"), and Bank One Trust Company, N.A., a national banking association, as
trustee (the "Trustee").

                  WHEREAS, the Company executed and delivered the indenture
dated as of June 19, 2002 (the "Base Indenture"), to the Trustee to provide for
the future issuance of the Company's unsecured debentures, notes or other
evidence of indebtedness (the "Securities"), to be issued from time to time in
one or more series as determined by the Company under the Base Indenture;

                  WHEREAS, pursuant to the terms of the Base Indenture, the
Company desires to provide for the establishment of a new series of its
Securities to be known as its 7.20% Senior Notes due 2012 (the "Notes"), the
form and substance of such Notes and the terms, provisions and conditions
thereof to be set forth as provided in the Base Indenture and this First
Supplemental Indenture (together, the "Indenture"); and

                  WHEREAS, the Company has requested that the Trustee execute
and deliver this First Supplemental Indenture and all requirements necessary to
make this First Supplemental Indenture a valid instrument in accordance with its
terms, and to make the Notes, when executed by the Company and authenticated and
delivered by the Trustee, the valid obligations of the Company, and all acts and
things necessary have been done and performed to make this First Supplemental
Indenture enforceable in accordance with its terms, and the execution and
delivery of this First Supplemental Indenture has been duly authorized in all
respects.

                  NOW THEREFORE, in consideration of the purchase and acceptance
of the Notes by the Holders thereof, and for the purpose of setting forth, as
provided in the Indenture, the form and substance of the Notes and the terms,
provisions and conditions thereof, the Company covenants and agrees with the
Trustee as follows:

                                   ARTICLE I

                                   DEFINITIONS

                  SECTION 1.1. Definition of Terms.

                  Unless the context otherwise requires:

                  (a) a term defined in the Base Indenture has the same meaning
when used in this First Supplemental Indenture;

                  (b) a term defined anywhere in this First Supplemental
Indenture has the same meaning throughout;

                  (c) a term defined in both the Base Indenture and in this
First Supplemental Indenture shall have the meaning set forth in this First
Supplemental Indenture;



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                                                                               2


                  (d) the singular includes the plural and vice versa;

                  (e) headings are for convenience of reference only and do not
affect interpretation; and

                  (f) the following terms have the meanings given to them in
this Section 1.1(f):

                  "Capitalized Lease Obligation" means an obligation that is
         required to be classified and accounted for as a capitalized lease for
         financial reporting purposes in accordance with GAAP, and the amount of
         Indebtedness represented by such obligation shall be the capitalized
         amount of such obligation determined in accordance with such
         principles.

                  "Comparable Treasury Issue" means the United States Treasury
         security selected by the Independent Investment Banker as having a
         maturity comparable to the remaining term of the Notes to be redeemed
         that would be used, at the time of selection and in accordance with
         customary market practice, in pricing new issues of corporate debt
         securities of comparable maturity to the remaining term of the Notes.

                  "Comparable Treasury Price" means, with respect to any
         Redemption Date: (i) the average of the bid and asked prices for the
         Comparable Treasury Issue (expressed as a percentage of its principal
         amount) on the third Business Day preceding the Redemption Date, as set
         forth in the daily statistical release (or any successor release)
         published by the Federal Reserve Bank of New York and designated
         "Composite 3:30 p.m. Quotations for U.S. Government Securities," or
         (ii) if such release (or any successor release) is not published or
         does not contain such prices on such Business Day, (A) the average of
         the Reference Treasury Dealer Quotations for such Redemption Date,
         after excluding the highest and lowest of such Reference Treasury
         Dealer Quotations, or (B) if the Trustee obtains fewer than three such
         Reference Treasury Dealer Quotations, the average of all such Reference
         Treasury Dealer Quotations so received.

                  "Consolidated Net Worth" means the excess of assets over
         liabilities of the Company and its consolidated subsidiaries, plus
         minority interest, as determined from time to time in accordance with
         GAAP.

                  "Consolidated Tangible Assets" means, on the date of any
         determination, total assets less goodwill and other intangibles of the
         Company and its consolidated subsidiaries, in each case as set forth on
         the most recently available consolidated balance sheet of the Company
         and its consolidated subsidiaries in accordance with GAAP.

                  "GAAP" means generally accepted accounting principles in the
         United States of America as in effect as of the date of this First
         Supplemental Indenture, including those set forth in the opinions and
         pronouncements of the Accounting Principles Board of the American
         Institute of Certified Public Accountants and statements and
         pronouncements of the Financial Accounting Standards Board or in such
         other statements by such other entity as approved by a significant
         segment of the accounting profession. All ratios and


<PAGE>
                                                                               3


         computations based on GAAP contained in the Indenture will be computed
         in conformity with GAAP.

                  "Independent Investment Banker" means one of the Reference
         Treasury Dealers appointed by the Company.

                  "Issue Date" shall mean the first date on which a Note is
         authenticated by the Trustee pursuant to this First Supplemental
         Indenture.

                  "Permitted Liens" shall mean, with respect to any Person: (i)
         Liens existing on the Issue Date; (ii) Liens on property or assets of,
         or any shares of stock of or secured debt of, any corporation existing
         at the time such corporation becomes a Restricted Subsidiary of the
         Company or any of its Restricted Subsidiaries or at the time such
         corporation is merged into the Company or any of its Restricted
         Subsidiaries; (iii) Liens in favor of the Company or any of its
         Restricted Subsidiaries; (iv) Liens in favor of governmental bodies to
         secure progress or advance payments; (v) Liens securing industrial
         revenue or pollution control bonds; (vi) Liens on Property to secure
         Indebtedness incurred for the purpose of (a) financing all or any part
         of the purchase price of such Property incurred prior to, at the time
         of, or within 180 days after, the acquisition of such Property or (b)
         financing all or any part of the cost of construction, improvement,
         development or expansion of any such Property; (vii) statutory liens or
         landlords', carriers', warehouseman's, mechanics', suppliers',
         materialmen's, repairmen's or other like Liens arising in the ordinary
         course of business and with respect to amounts not yet delinquent or
         being contested in good faith by appropriate proceedings, if a reserve
         or other appropriate provisions, if any, as shall be required in
         conformity with GAAP shall have been made therefor; (viii) Liens
         incurred in connection with any accounts receivable programs up to an
         aggregate of $125 million; (ix) Liens on current assets of the Company
         or its Restricted Subsidiaries securing Indebtedness of the Company or
         its Restricted Subsidiaries and Liens in connection with Sale and
         Leaseback Transactions; provided that at the time of the incurrence of
         such Indebtedness or the entering into of such Sale and Leaseback
         Transaction, the aggregate amount of Indebtedness (other than
         Indebtedness secured by Liens described in clauses (i) through (viii)
         above) of the Company and its Restricted Subsidiaries secured by Liens
         does not exceed 10% of Consolidated Tangible Assets; and (x) any
         extensions, substitutions, replacements or renewals in whole or in part
         of a Lien (an "existing Lien") enumerated in clauses (i) through (ix)
         above; provided that the Lien may not extend beyond (A) the Property or
         Indebtedness subject to the existing Lien and (B) improvements and
         construction on such Property and the Indebtedness secured by the Lien
         may not exceed the Indebtedness secured at the time by the existing
         Lien.

                  "Principal Property" means any manufacturing plant or
         warehouse owned or leased by the Company or any Subsidiary, the gross
         book value of which exceeds four percent of Consolidated Net Worth,
         other than manufacturing plants and warehouses which the Board of
         Directors by resolution declares, together with all other plants and
         warehouses previously so declared, is not of material importance to the
         total business conducted by the Company and its Restricted Subsidiaries
         as an entirety.


<PAGE>
                                                                               4


                  "Property" of any Person means all types of real, personal,
         tangible, intangible or mixed property owned by such Person whether or
         not included in the most recent consolidated balance sheet of the
         Company and its consolidated subsidiaries under GAAP.

                  "Reference Treasury Dealer" means each of Goldman, Sachs & Co.
         and J.P. Morgan Securities Inc. and their respective successors;
         provided, however, that if any of the foregoing shall cease to be a
         primary U.S. government securities dealer in New York City (a "Primary
         Treasury Dealer"), the Company shall substitute therefor another
         Primary Treasury Dealer.

                  "Reference Treasury Dealer Quotations" means, with respect to
         each Reference Treasury Dealer and any Redemption Date, the average, as
         determined by the Trustee, of the bid and asked prices for the
         Comparable Treasury Issue (expressed in each case as a percentage of
         its principal amount) quoted in writing to the Trustee by such
         Reference Treasury Dealer at 5:00 p.m. (New York City time) on the
         third Business Day preceding such Redemption Date.

                  "Restricted Subsidiary" shall mean any Subsidiary of the
         Company that is not an Unrestricted Subsidiary.

                  "Unrestricted Subsidiary" means (1) any Subsidiary not
         organized under the laws of a state of the United States or the
         District of Columbia and any Subsidiary of such Subsidiary which is not
         organized under the laws of a state of the United States or the
         District of Columbia and (2) any Subsidiaries that at the time of
         determination shall be designated an Unrestricted Subsidiary by the
         Board of Directors and any Subsidiary of such Subsidiary. The Board of
         Directors may designate any Subsidiaries (including any newly-acquired
         or newly-formed Subsidiary) organized under the laws of a state of the
         United States or of the District of Columbia to be an Unrestricted
         Subsidiary unless such Subsidiary owns any capital stock of, or owns or
         holds any Property of, the Company or any other Restricted Subsidiary,
         provided, however, that the Subsidiary to be so designated has total
         assets of $35,000,000 or less.

                  "Treasury Rate" means, with respect to any Redemption Date,
         the rate per annum equal to the semi-annual equivalent yield to
         maturity of the Comparable Treasury Issue, assuming a price for the
         Comparable Treasury Issue (expressed as a percentage of its principal
         amount) equal to the Comparable Treasury Price for that Redemption
         Date.

                                   ARTICLE II

                   GENERAL TERMS AND CONDITIONS OF THE NOTES

                  SECTION 2.1. Designation and Principal Amount.

                  The Notes are hereby authorized and are designated the 7.20%
Senior Notes due 2012, unlimited in aggregate principal amount. The Notes issued
on the date hereof pursuant to


<PAGE>
                                                                               5


the terms of this Indenture will be in an aggregate principal amount of
$300,000,000, which amount shall be set forth in the written order of the
Company for the authentication and delivery of the Notes pursuant to Section 303
of the Base Indenture. In addition, the Company may issue, from time to time in
accordance with the provisions of this Indenture, additional Notes ranking
equally and ratably with the Notes issued hereunder in all respects (or in all
respects except for the payment of interest following the Issue Date of such
further Notes), so that such further Notes shall be consolidated and form a
single series with the Notes and shall be governed by the terms of this
Indenture.

                  SECTION 2.2. Maturity.

                  The principal amount of the Notes will be payable on June 15,
2012.

                  SECTION 2.3. Form and Payment.

                  The Notes will be issued as global notes, in fully registered
book-entry form without coupons in denominations of $1,000 and integral
multiples thereof.

                  Principal, premium, if any, and/or interest, if any, on the
global notes representing the Notes will be made to The Depository Trust Company
(the "Depositary").

                  The global notes representing the Notes will be deposited
with, or on behalf of, the Depositary and will be registered in the name of the
Depositary or a nominee of the Depositary. No global note may be transferred
except as a whole by a nominee of the Depositary to the Depositary or to another
nominee of the Depositary, or by the Depositary or such nominee to a successor
of the Depositary or a nominee of such successor.

                  So long as the Depositary or its nominee is the registered
owner of a global note, the Depositary or its nominee, as the case may be, will
be the sole Holder of the Notes represented thereby for all purposes under the
Indenture. Except as otherwise provided herein, each actual purchaser of each
Note represented by a global note ("Beneficial Owner") will not be entitled to
receive physical delivery of certificated Notes and will not be considered the
holders thereof for any purpose under the Indenture, and no global note
representing the Notes shall be exchangeable or transferable. Accordingly, each
Beneficial Owner must rely on the procedures of the Depositary and, if such
Beneficial Owner is not a participant, on the procedures of the participant
through which such Beneficial Owner owns its interest in order to exercise any
rights of a Holder under such global note or the Indenture.

                  The global notes representing the Notes will be exchangeable
for certificated Notes of like tenor and terms and of differing authorized
denominations aggregating a like principal amount, only if (i) the Depositary
notifies the Company that it is unwilling or unable to continue as Depositary
for the global debt securities, (ii) the Depositary ceases to be a clearing
agency registered under the Exchange Act and a successor to the Depository is
not appointed by the Company within 90 days, (iii) the Company in its sole
discretion determines that the global notes shall be exchangeable for
certificated Notes and notifies the Trustee of such determination or (iv) there
shall have occurred and be continuing an Event of Default under the Indenture
with


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                                                                               6


respect to the Notes. Upon any such exchange, the certificated Notes shall be
registered in the names of the Beneficial Owners of the global notes
representing the Notes, which names shall be provided by the Depositary's
relevant participants (as identified by the Depositary) to the Trustee. In such
event the Company will execute, and subject to Section 303 of the Indenture, the
Trustee, upon receipt of an Officer's Certificate evidencing such determination
by the Company, will authenticate and deliver the Notes in definitive registered
form without coupons, in authorized denominations, and in an aggregate principal
amount equal to the principal amount of the global notes in exchange for such
global notes. Upon the exchange of the global notes for such Notes in definitive
registered form without coupons, in authorized denominations, the global notes
shall be cancelled by the Trustee. Such Notes in definitive registered form
issued in exchange for the global notes shall be registered in such names and in
such authorized denominations as the Depositary, pursuant to instructions from
its direct or indirect participants or otherwise, shall instruct the Trustee.
The Trustee shall deliver such Notes to the Depositary for delivery to the
Persons in whose names such Notes are so registered.

                  SECTION 2.4. Interest.

                  The Notes shall bear interest at a rate equal to 7.20% per
annum. Interest on the Notes shall accrue from June 19, 2002, or from the most
recent interest payment date to which interest has been paid or duly provided
upon for the Notes, as the case may be. Interest on the Notes shall be payable
semi-annually in arrears on June 15 and December 15, commencing December 15,
2002 (each an "Interest Payment Date"), to the persons in whose names the Notes
are registered at the close of business on June 1 and December 1, as the case
may be, preceding such Interest Payment Date.

                                  ARTICLE III

                             REDEMPTION OF THE NOTES

                  SECTION 3.1. Optional Redemption.

                  The Notes will be redeemable, in whole or in part, at the
option of the Company at any time, upon not less than 30 nor more than 60 days'
notice, at a Redemption Price equal to the greater of (i) 100% of the principal
amount of the Notes, or (ii) as determined by the Independent Investment Banker,
the sum of the present values of the remaining scheduled payments of principal
and interest on the Notes to be redeemed (not including the portion of any such
payments of interest accrued as of the Redemption Date), discounted to the
Redemption Date in accordance with customary market practice on a semi-annual
basis (assuming a 360-day year consisting of twelve 30-day months) at the
Treasury Rate plus 40 basis points, plus, in each case, accrued and unpaid
interest thereon to the Redemption Date. Unless the Company defaults in payment
of the Redemption Price, on and after the Redemption Date, interest will cease
to accrue on the Notes, or portions thereof called for redemption.

                  If less than all of the Notes are to be redeemed, the Trustee
will select the Notes to be redeemed by such method as the Trustee shall deem
fair and appropriate. The Trustee may select for redemption Notes and portions
of the Notes in amounts of whole multiples of $1,000.


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                                                                               7


                  SECTION 3.2. No Sinking Fund.

                  The Notes are not entitled to the benefit of any sinking fund.

                                   ARTICLE IV

                                    COVENANTS

                  SECTION 4.1. Amendments to Article 10 of the Base Indenture.

                  Article 10 of the Base Indenture is hereby amended in respect
of the Notes and only in respect of the Notes by adding Sections 1009, 1010 and
1011 as follows:

                           SECTION 1009.  LIMITATION ON LIENS.

                           The Company will not, and will not permit any of its
                  Restricted Subsidiaries to, create, incur or otherwise cause
                  to exist or become effective any Liens of any kind upon any
                  asset now owned or hereafter acquired unless all payments due
                  under the Indenture and the Notes are secured on an equal and
                  ratable basis with the obligations so secured until such time
                  as such obligations are no longer secured by a Lien, except
                  for Permitted Liens.

                           SECTION 1010.  LIMITATION ON SALE AND LEASEBACK
                                          TRANSACTIONS.

                           Neither the Company nor any Restricted Subsidiary
                  will enter into any sale and leaseback transaction with
                  respect to any Principal Property (except for temporary leases
                  of a term, including renewals, not exceeding five years)
                  unless either (a) the Company or such Restricted Subsidiary
                  would be entitled, pursuant to the provisions of the
                  Indenture, to incur Indebtedness secured by a Lien on the
                  property to be leased without equally and ratably securing the
                  Notes, or (b) the Company within 180 days after the effective
                  date of such transaction applies to the voluntary retirement
                  of its funded debt an amount equal to the value of such
                  transaction, defined as the greater of the net proceeds of the
                  sale of the property leased in such transaction or the fair
                  value, in the opinion of the Board of Directors, of the leased
                  property at the time such transaction was entered into.

                           SECTION 1011.  WAIVER OF CERTAIN COVENANTS.

                           Compliance with Sections 1009 and 1010 may not be
                  waived by the Trustee unless the Holders of at least a
                  majority in aggregate principal amount of the Notes
                  Outstanding consent to such waiver; provided, however, that
                  the Company need not comply with Sections 1009 and 1010 in the
                  event it elects to comply with Section 1302 or Section 1303 of
                  this Indenture.


<PAGE>
                                                                               8


                                   ARTICLE V


                 CONSOLIDATION, MERGER, LEASE, SALE OR TRANSFER

                  SECTION 5.1. Amendments to Article 8 of the Base Indenture.

                  Article 8 of the Base Indenture is hereby amended in respect
of the Notes and only in respect of the Notes by deleting Section 801 in its
entirety and replacing it with Section 801 as follows:

                  SECTION 801. WHEN COMPANY MAY MERGE, ETC.

                           The Company shall not consolidate or merge with or
                  into, or sell, lease, convey or otherwise dispose of all or
                  substantially all of its assets or assign any of its
                  obligations under this Indenture or under the First
                  Supplemental Indenture, dated as of June 19, 2002 (the "First
                  Supplemental Indenture") to another entity unless:

                           (1) the entity formed by or surviving any such
                  consolidation or merger (if other than the Company), or to
                  which such sale, lease, conveyance or other disposition shall
                  have been made (the "Surviving Entity"), is a corporation
                  organized and existing under the laws of the United States,
                  any state thereof, or the District of Columbia;

                           (2) the Surviving Entity expressly assumes by
                  supplemental indenture all of the obligations of the Company
                  under the Notes (as defined in the First Supplemental
                  Indenture), this Indenture and the First Supplemental
                  Indenture; and

                           (3) immediately after giving effect to such
                  transaction, no Default or Event of Default shall have
                  occurred and be continuing.

                                   ARTICLE VI

                                  FORM OF NOTES

                  SECTION 6.1. Form of Notes.

                  The Notes and the Trustee's Certificates of Authentication to
be endorsed thereon are to be substantially in the form of Exhibit A, which form
is hereby incorporated in and made a part of this First Supplemental Indenture.

                  The terms and provisions contained in the Notes shall
constitute, and are hereby expressly made, a part of this First Supplemental
Indenture, and the Company and the Trustee, by their execution and delivery of
this First Supplemental Indenture, expressly agree to such terms and provisions
and to be bound thereby.


<PAGE>
                                                                               9


                                  ARTICLE VII

                             ORIGINAL ISSUE OF Notes

                  SECTION 7.1. Original Issue of Notes.

                  Notes in the aggregate principal amount of $300,000,000 may,
upon execution of this First Supplemental Indenture, be executed by the Company
and delivered to the Trustee for authentication, and the Trustee shall thereupon
authenticate and deliver said Notes to or upon Company Order.

                                  ARTICLE VIII

                                  MISCELLANEOUS

                  SECTION 8.1. Ratification of Indenture.

                  The Base Indenture as supplemented by this First Supplemental
Indenture, is in all respects ratified and confirmed, and this First
Supplemental Indenture shall be deemed part of the Indenture in the manner and
to the extent herein and therein provided.

                  SECTION 8.2. Trustee Not Responsible for Recitals.

                  The recitals herein contained are made by the Company and not
by the Trustee, and the Trustee assumes no responsibility for the correctness
thereof. The Trustee makes no representation as to the validity or sufficiency
of this First Supplemental Indenture.

                  SECTION 8.3. Governing Law.

                  This First Supplemental Indenture and each Note shall be
deemed to be a contract made under the laws of the State of New York, and the
rights and duties of the parties hereunder and thereunder shall be governed by,
and construed in accordance with, the law of the State of New York.

                  SECTION 8.4. Severability.

                  In case any one or more of the provisions contained in this
First Supplemental Indenture or in the Notes shall for any reason be held
invalid, illegal or unenforceable in any respect, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions shall not in any way be affected or impaired thereby, it being
intended that all of the provisions of this First Supplemental Indenture or of
the Notes shall be construed as if such invalid or illegal or unenforceable
provision had never been contained herein or therein.


<PAGE>
                                                                              10


                  SECTION 8.5. Counterparts.

                  This First Supplemental Indenture may be executed in any
number of counterparts each of which shall be an original; but such counterparts
shall together constitute but one and the same instrument.

                [remainder of the page left intentionally blank]


<PAGE>
                                                                              11


         IN WITNESS WHEREOF, the parties hereto have caused this First
Supplemental Indenture to be duly executed, and their respective corporate seals
to be affixed and attested, on the date or dates indicated in the
acknowledgments and as of the day and year first above written.

                                        KENNAMETAL INC., as Issuer


                                        By  /s/ James E. Morrison
                                           --------------------------------
                                        Name: James E. Morrison
                                        Title: Vice President and Treasurer



                                        BANK ONE TRUST COMPANY, N.A.,
                                        as Trustee

                                        By  /s/ Jeffery L. Eubank
                                           ------------------------------
                                        Name: Jeffery L. Eubank
                                        Title: Authorized Officer


<PAGE>


                                                                       EXHIBIT A

                             (FORM OF SENIOR NOTES)


                  This Note is a Global Note within the meaning of the Indenture
hereinafter referred to and is registered in the name of the Depositary or a
nominee of the Depositary. This Note is exchangeable for Notes registered in the
name of a person other than the Depositary or its nominee only in the limited
circumstances described in the Indenture, and no transfer of this Note (other
than a transfer of this Note as a whole by the Depositary to a nominee of the
Depositary or by a nominee of the Depositary to the Depositary or another
nominee of the Depositary) may be registered except in limited circumstances.

                  Unless this Note is presented by an authorized representative
of The Depository Trust Company, a New York corporation (55 Water Street, New
York, New York), to the issuer or its agent for registration of transfer,
exchange or payment, and any Note issued is registered in the name of Cede & Co.
or in such other name as is requested by an authorized representative of The
Depository Trust Company (and any payment is made to Cede & Co. or such other
entity as is requested by an authorized representative of The Depository Trust
Company), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR
TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co.,
has an interest herein.



<PAGE>


FORM OF SENIOR NOTES                                                         A-1


                                 KENNAMETAL INC.
                           ___% Senior Notes due 2012

No.  __________________                                         $_______________
CUSIP No:  ____________________

                  KENNAMETAL INC., a corporation duly organized and existing
under the laws of the Commonwealth of Pennsylvania (the "Company", which term
includes any successor corporation under the Indenture hereinafter referred to),
for value received, hereby promises to pay to Cede & Co., or registered assigns,
the principal sum of ________________________ dollars ($___________) on _______,
2012 (such date is hereinafter referred to as the "Maturity Date"), and to pay
interest on said principal sum from __________, 20__, or from the most recent
interest payment date (each such date, an "Interest Payment Date") to which
interest has been paid or duly provided for, semi-annually in arrears on _______
and _______ of each year, commencing on _______, 20__, at the rate of ___% per
annum until the principal hereof shall have become due and payable. The interest
so payable, and punctually paid or duly provided for, on any Interest Payment
Date will, as provided in the Indenture, be paid to the Person in whose name
this Note (or one or more Predecessor Securities) is registered at the close of
business on the regular record date for such interest which shall be the close
of business on the _______ or _______, (whether or not a Business Day), as the
case may be, preceding such Interest Payment Date. Any such interest not
punctually paid or duly provided for shall forthwith cease to be payable to the
registered Holders on such regular record date and may be paid to the Person in
whose name this Note (or one or more Predecessor Securities) is registered at
the close of business on a Special Record Date for the payment of such Defaulted
Interest to be fixed by the Trustee, notice whereof shall be given to the
registered Holders of this series of Notes not less than 10 days prior to such
Special Record Date, or may be paid at any time in any other lawful manner not
inconsistent with the requirements of any securities exchange on which the Notes
of this series may be listed, and upon such notice as may be required by such
exchange, all as more fully provided in the Indenture. The principal of, and
premium, if any, and the interest on this Note shall be payable at the office or
agency of the Trustee maintained for that purpose in the Borough of Manhattan,
The City of New York, in any coin or currency of the United States of America
that at the time of payment is legal tender for payment of public and private
debts; provided, however, that payment of interest may be made at the option of
the Company by check mailed to the registered Holder at such address as shall
appear in the Security Register.

                  The indebtedness evidenced by this Note is, to the extent
provided in the Indenture, senior and unsecured and will rank in right of
payment on parity with all other senior unsecured obligations of the Company.
Each Holder of this Note by accepting the same, (a) agrees to and shall be bound
by such provisions and (b) appoints the Trustee his or her attorney-in-fact for
any and all such purposes.

                  This Note shall not be entitled to any benefit under the
Indenture hereinafter referred to, be valid or become obligatory for any purpose
until the Certificate of Authentication hereon shall have been signed by or on
behalf of the Trustee.

                  The provisions of this Note are continued on the reverse side
hereof and such continued provisions shall for all purposes have the same effect
as though fully set forth at this place.


<PAGE>


FORM OF SENIOR NOTES                                                         A-2

                  IN WITNESS WHEREOF, the Company has caused this instrument to
be executed.

Dated: ____________, 20__
                                             KENNAMETAL INC.

                                             By:______________________________
                                                 Name:
                                                 Title:
Attest:
By:______________________________
    Name:
    Title:


<PAGE>


FORM OF SENIOR NOTES                                                         A-4


                          CERTIFICATE OF AUTHENTICATION

                  This is one of the Notes of the series of Notes described in
the within-mentioned Indenture.

Dated:___________________________



BANK ONE TRUST COMPANY, N.A., as Trustee


By______________________________
   Authorized Signatory


<PAGE>


FORM OF SENIOR NOTES                                                         A-5

                                (REVERSE OF NOTE)
                                 KENNAMETAL INC.
                           ___% Senior Notes due 2012

                  This Note is one of a duly authorized series of Securities of
the Company (herein sometimes referred to as the "Securities") specified in the
Indenture (as defined below), all issued or to be issued in one or more series
under and pursuant to an Indenture dated as of June 19, 2002 (the "Base
Indenture"), duly executed and delivered between the Company and Bank One Trust
Company, N.A., as Trustee (the "Trustee"), as supplemented by a First
Supplemental Indenture, dated June 19, 2002 (the Base Indenture as so
supplemented, the "Indenture"), to which Indenture and all indentures
supplemental thereto reference is hereby made for a description of the rights,
limitations of rights, obligations, duties and immunities thereunder of the
Trustee, the Company and the Holders of the Securities and of the terms upon
which the Securities are, and are to be, authenticated and delivered. By the
terms of the Indenture, the Securities are issuable in series that may vary as
to amount, date of maturity, rate of interest and in other respects as provided
in the Indenture.

                  The Notes are not entitled to the benefit of any sinking fund.

                  The Notes will be redeemable, in whole or in part, at the
option of the Company at any time, upon not less than 30 nor more than 60 days'
notice, at a Redemption Price equal to the greater of (i) 100% of the principal
amount of the Notes, or (ii) as determined by the Independent Investment Banker,
the sum of the present values of the remaining scheduled payments of principal
and interest on the Notes to be redeemed (not including the portion of any such
payments of interest accrued as of the Redemption Date) discounted to the
Redemption Date in accordance with customary market practice on a semi-annual
basis (assuming a 360-day year consisting of twelve 30-day months) at the
Treasury Rate plus __ basis points, plus, in each case, accrued and unpaid
interest thereon to the Redemption Date. Unless the Company defaults in payment
of the Redemption Price, on and after the Redemption Date, interest will cease
to accrue on the Notes or portions thereof called for redemption.

                  "Comparable Treasury Issue" means the United States Treasury
security selected by the Independent Investment Banker as having a maturity
comparable to the remaining term of the Notes to be redeemed that would be used,
at the time of selection and in accordance with customary market practice, in
pricing new issues of corporate debt securities of comparable maturity to the
remaining term of the Notes.

                  "Comparable Treasury Price" means, with respect to any
Redemption Date: (i) the average of the bid and asked prices for the Comparable
Treasury Issue (expressed as a percentage of its principal amount) on the third
Business Day preceding the Redemption Date, as set forth in the daily
statistical release (or any successor release) published by the Federal Reserve
Bank of New York and designated "Composite 3:30 p.m. Quotations for U.S.
Government Securities," or (ii) if such release (or any successor release) is
not published or does not contain such prices on such Business Day, (A) the
average of the Reference Treasury Dealer Quotations for such Redemption Date,
after excluding the highest and lowest of such Reference Treasury Dealer


<PAGE>


FORM OF SENIOR NOTES                                                         A-6


Quotations, or (B) if the Trustee obtains fewer than three such Reference
Treasury Dealer Quotations, the average of all such Reference Treasury Dealer
Quotations so received.

                  "Independent Investment Banker" means one of the Reference
Treasury Dealers appointed by the Company.

                  "Reference Treasury Dealer" means each of Goldman, Sachs & Co.
and J.P. Morgan Securities Inc. and their respective successors; provided,
however, that if any of the foregoing shall cease to be a primary U.S.
government securities dealer in New York City (a "Primary Treasury Dealer"), the
Company shall substitute therefor another Primary Treasury Dealer.

                  "Reference Treasury Dealer Quotations" means, with respect to
each Reference Treasury Dealer and any Redemption Date, the average, as
determined by the Trustee, of the bid and asked prices for the Comparable
Treasury Issue (expressed in each case as a percentage of its principal amount)
quoted in writing to the Trustee by such Reference Treasury Dealer at 5:00 p.m.
(New York City time) on the third Business Day preceding such Redemption Date.

                  "Treasury Rate" means, with respect to any Redemption Date,
the rate per annum equal to the semi-annual equivalent yield to maturity of the
Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue
(expressed as a percentage of its principal amount) equal to the Comparable
Treasury Price for that Redemption Date.

                  If less than all of the Notes of a series are to redeemed, the
Trustee will select the Notes to be redeemed by such method as the Trustee shall
deem fair and appropriate. The Trustee may select for redemption Notes and
portions of Notes in amounts of whole multiples of $1,000.

                  The Indenture contains provisions for defeasance of (a) the
entire indebtedness of this Note and (b) certain restrictive covenants upon
compliance by the Company with certain conditions set forth therein.

                  In case an Event of Default, shall have occurred and be
continuing, the principal of all of the Notes may be declared, and upon such
declaration shall become, due and payable, in the manner, with the effect and
subject to the conditions provided in the Indenture.

                  The Indenture contains provisions permitting the Company and
the Trustee, with the consent of the Holders of not less than a majority in
aggregate principal amount of the Notes of each series affected at the time
Outstanding, to execute supplemental indentures for the purpose of, among other
things, adding any provisions to or changing or eliminating any of the
provisions of the Indenture or of any supplemental indenture or of modifying the
rights of the Holders of the Notes; provided, however, that, among other things,
no such supplemental indenture shall (i) reduce the principal amount thereof, or
reduce the rate or extend the time of payment of interest thereon (subject to
the Company's right to defer such payments in the manner set forth herein), or
reduce any premium payable upon the redemption thereof, without the consent of
the Holder of each Note so affected, or (ii) reduce the aforesaid percentage of
Notes,


<PAGE>


FORM OF SENIOR NOTES                                                         A-7

the Holders of which are required to consent to any such supplemental indenture,
without the consent of the Holders of each Note then Outstanding and affected
thereby. The Indenture also contains provisions permitting, among other things,
the Holders of a majority in aggregate principal amount of the Securities of any
series at the time Outstanding affected thereby, on behalf of all of the Holders
of all Securities of such series, to waive a Default or Event of Default with
respect to such series, and its consequences, except a Default or Event of
Default in the payment of the principal of or premium, if any, or interest on
any of the Securities of such series. Any such consent or waiver by the
registered Holder of this Note (unless revoked as provided in the Indenture)
shall be conclusive and binding upon such Holder and upon all future Holders and
owners of this Note and of any Note issued in exchange for or in place hereof
(whether by registration of transfer or otherwise), irrespective of whether or
not any notation of such consent or waiver is made upon this Note.

                  No reference herein to the Indenture and no provision of this
Note or of the Indenture shall alter or impair the obligation of the Company,
which is absolute and unconditional, to pay the principal of and premium, if
any, and interest on this Note at the times, place and at the rates and in the
money herein prescribed.

                  As provided in the Indenture and subject to certain
limitations therein set forth, this Note is transferable by the registered
Holder hereof on the Security Register of the Company, upon surrender of this
Note for registration of transfer at the office or agency of the Trustee in The
City of New York duly endorsed by, or accompanied by, a written instrument or
instruments of transfer in form satisfactory to the Company or the Trustee duly
executed by the registered Holder hereof or his attorney duly authorized in
writing, and thereupon one or more new Notes of authorized denominations and for
the same aggregate principal amount and series will be issued to the designated
transferee or transferees. No service charge will be made for any such transfer,
but the Company may require payment of a sum sufficient to cover any tax or
other governmental charge payable in relation thereto.

                  Prior to due presentment for registration of transfer of this
Note, the Company, the Trustee, any Paying Agent and the Security Registrar may
deem and treat the registered Holder hereof as the absolute owner hereof
(whether or not this Note shall be overdue and notwithstanding any notice of
ownership or writing hereon made by anyone other than the Security Registrar)
for the purpose of receiving payment of or on account of the principal hereof
and premium, if any, and interest due hereon and for all other purposes, and
neither the Company nor the Trustee nor any Paying Agent nor any Security
Registrar shall be affected by any notice to the contrary.

                  No recourse shall be had for the payment of the principal of
or the interest on this Note, or for any claim based hereon, or otherwise in
respect hereof, or based on or in respect of the Indenture, against any
incorporator, shareholder, officer or director, past, present or future, as
such, of the Company or of any predecessor or successor corporation, whether by
virtue of any constitution, statute or rule of law, or by the enforcement of any
assessment or penalty or otherwise, and such liability being, by the acceptance
hereof and as part of the consideration for the issuance hereof, expressly
waived and released.


<PAGE>


FORM OF SENIOR NOTES                                                         A-8

                  The Indenture imposes certain limitations on the ability of
the Company to, among other things, merge or consolidate with any other Person,
sell, assign, transfer or lease all or substantially all of its properties or
assets or create or incur liens on certain of its property. All such covenants
and limitations are subject to a number of important qualifications and
exceptions. The Company must report periodically to the Trustee on compliance
with the covenants in the Indenture.

                  A director, officer, employee or stockholder, as such, of the
Company shall not have any liability for any obligations of the Company under
the Notes of this series or the Indenture or for any claim based on, in respect
of or by reason of, such obligations or their creation. Each Holder, by
accepting a Note, waives and releases all such liability. The waiver and release
are part of the consideration for the issuance of this Note.

                  Pursuant to a recommendation promulgated by the Committee on
Uniform Security Identification Procedures ("CUSIP"), the Company has caused
CUSIP numbers to be printed on the Notes. No representation is made as to the
correctness or accuracy of such numbers as printed on the Notes and reliance may
be placed only on the other identification numbers printed hereon.

                  The Notes of this series are issuable only in fully registered
book-entry form without coupons in denominations of $1,000 and any integral
multiple thereof. This Global Note is exchangeable for Notes in definitive form
only under certain limited circumstances set forth in the Indenture. As provided
in the Indenture and subject to certain limitations therein set forth, Notes of
this series so issued are exchangeable for a like aggregate principal amount of
Notes of this series of a different authorized denomination, as requested by the
Holder surrendering the same.

                  This Note shall be governed by and construed in accordance
with the law of the State of New York.

                  All terms used in this Note that are defined in the Indenture
shall have the meanings assigned to them in the Indenture.


<PAGE>


FORM OF SENIOR NOTES                                                         A-9


                                   ASSIGNMENT


To assign this Security, fill in the form below: (I) or (we) assign and transfer
this Security to:



              --------------------------------------------------------------
              (Insert assignee's social security or tax I.D. number)


              --------------------------------------------------------------
              --------------------------------------------------------------
              --------------------------------------------------------------
              --------------------------------------------------------------
              (Print or type assignee's name, address and zip code)

and irrevocably appoint
                        --------------------------------------------------------
agent to transfer this Security on the books of the Company. The agent may
substitute another to act for him.

Dated:                             Your Signature:
      ------------------------                    ------------------------------
                                                     (Sign exactly as your name
                                                      appears on the other side
                                                      of this Security)


Signature Guaranty:
                    -----------------------------------------------------------
                       (Signatures must be guaranteed by an "eligible guarantor
                       institution" meeting the requirements of the Transfer
                       Agent, which requirements will include membership or
                       participation in STAMP or such other "signature guarantee
                       program" as may be determined by the Transfer Agent in
                       addition to, or in substitution for, STAMP all in
                       accordance with the Exchange Act.)



Social Security Number or Taxpayer Identification Number: ______________________