Sir
How you send your invoice to your job worker? Can you send the format?
However in plain reading of the illustration i am of the view that there is no TDS attracted on this transaction since proper sale invoice is raised and excise duty and vat is collected from you.
There may be a contract to fix your part with another part but that does not automatically constitute contract of service. If nothing is done the job worker will return your product. In that case you will credit their account as material return or sale return.
Since Excise and vat is collected by your job worker the process is confirmed as manufacture of a new product hence you sell one product and he sells you another product and hence TDS is not applicable for sale of goods.
Take an example of purchase order (also a contract) sheduling the supplier to deliver at various dates with various quantities. This cannot be considered as contract under section 194C. What you get is a purchased goods and not a service.