Excise exemption for job-work goods used in defence production permits duty-free use subject to evidence and liability undertakings. An exemption from central excise duty applies to goods manufactured as job work when used by specified undertakings in or in relation to the manufacture of final products supplied to the Ministry of Defence. Job work is defined as processing raw or semi finished inputs. The exemption excludes certain machines, specified packaging materials, gas cylinders, specific fabric sacks and plywood. Conditions require an undertaking to the Commissioner, evidence of use and supply to the Ministry of Defence, and acceptance of liability for excise on the final products.