Exemption for job workers where the principal pays excise duty under rule 7AA and compliance obligations are met. Exemption from rule 174 is granted for job workers undertaking work on final products under Chapter 62, provided the principal pays the excise duty under rule 7AA and the parties comply with all procedural formalities and liabilities under the Central Excise Act and rules. The exemption does not apply where the job worker is authorised to pay the excise duty in accordance with the proviso to rule 7AA.