St liability on job work services under reverse charge

JOB worker services is not covered under reverse charge. But can you tell me what exactly is he doing?

No service tax is payable by job-workers on processes amounting to manufacture'.........

In Job work if it a pure labour or service charges it does not become a works contract and accordingly reverse charge mechanism is not applicable.

However in some cases the Job worker may put some material on his own on the material supplied by us for completing the work.In such case he charges vat also as there is transfer of property.This may qualify as works contract as the revised definition of works contract covers movable property also.

If the job work qualifies a works contract and the service provider is non corporate entity reverse charge mechanism becomes applicable.

Whether RCM and WCT is applicable if invoice mention JOB WORK only and output doesnt amounts to Manufacture ?? Service is done on Factory of client , no own material is used, and invoice raised by party (without VAT and service tax ) ??