Secure document for manual worker? (4,4)
I believe the answer is:
nail file
'manual worker?' is the definition.
(tool used to work on one's hands)
'secure document' is the wordplay.
'secure' becomes 'nail' (both can mean to apprehend or capture).
'document' becomes 'file'.
'nail'+'file'='NAIL-FILE'
'for' is the link.
(Other definitions for nail file that I've seen before include "Manicure item" , "Manicurist's tool" , "Roughened metal strip for trimming horny hands" , "Manicurist item" , "accessory to grooming" .)