Rule 16 and Rule 4(5)

hi.....

Accoding to Rule 16A of Central Excise Rules goods can be removed for job work without payment of duty...But according to Rule 4(5) of CCR rules duty is required to be paid when removed for job work....arn't these rules contradictory?? Rule 4(5) also specifies time limit for receiving back of such inputs.....Kindly explain.

i wud really appreciate if any body could give me a complete picture regarding provisions of job work like who is required to pay duty, significance of EN 214/86.

thank u