KADANT INC. % Note Due

Exhibit 4.3

UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR SECURITIES IN DEFINITIVE REGISTERED FORM, THIS SECURITY MAY NOT BE TRANSFERRED EXCEPT 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 OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITARY. UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), 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.

KADANT INC.

[    ]% Note Due [    ]

KADANT INC., a Delaware corporation (“Issuer”, which term includes any successor corporation), for value received promises to pay to CEDE & CO. or registered assigns, the principal sum of             on             .

Interest Payment Dates:             and             (each, an “Interest Payment Date”), commencing on             .

Interest Record Dates:             and             (each, an “Interest Record Date”).

Reference is made to the further provisions of this Security contained herein, which will for all purposes have the same effect as if set forth at this place.

1

IN WITNESS WHEREOF, the Issuer has caused this Security to be signed manually or by facsimile by its duly authorized officer under its corporate seal.

2

This is one of the series designated herein and referred to in the within-mentioned Indenture.

Dated: [    ]

3

(REVERSE OF SECURITY)

KADANT INC.

[    ]% Note Due [    ]

KADANT INC., a Delaware corporation (the “Issuer”), promises to pay interest on the principal amount of this Security at the rate per annum shown above. Cash interest on the Securities will accrue from the most recent date to which interest has been paid or, if no interest has been paid, from             . The Issuer will pay interest semi-annually in arrears on each Interest Payment Date, commencing             . Interest will be computed on the basis of a 360-day year of twelve 30-day months.

The Issuer shall pay interest on overdue principal from time to time on demand at the rate borne by the Securities and on overdue installments of interest (without regard to any applicable grace periods) to the extent lawful.

The Issuer shall pay interest on the Securities (except defaulted interest) to the persons who are the registered Holders at the close of business on the Interest Record Date immediately preceding the Interest Payment Date notwithstanding any transfer or exchange of such Security subsequent to such Interest Record Date and prior to such Interest Payment Date. Holders must surrender Securities to the Trustee to collect principal payments. The Issuer shall pay Principal and interest in money of the United States that at the time of payment is legal tender for payment of public and private debts (“U.S. Legal Tender”). However, the payments of interest, and any portion of the Principal (other than interest payable at maturity or on any redemption or repayment date or the final payment of Principal) shall be made by the Paying Agent, upon receipt from the Issuer of immediately available funds by             [a./p.m.], New York City time (or such other time as may be agreed to between the Issuer and the Paying Agent or the Issuer), directly to a Holder (by Federal funds wire transfer or otherwise) if the Holder has delivered written instructions to the Trustee 15 days prior to such payment date requesting that such payment will be so made and designating the bank account to which such payments shall be so made and in the case of payments of Principal surrenders the same to the Trustee in exchange for a Security or Securities aggregating the same principal amount as the unredeemed principal amount of the Securities surrendered.

Initially,             (the “Trustee”) will act as Paying Agent. The Issuer may change any Paying Agent without notice to the Holders.

The Issuer issued the Securities under an Indenture, dated as of             ,     &n