Components of antimony finally used to engrave? (9)
I believe the answer is:
sandblast
'to engrave?' is the definition.
'components of antimony finally' is the wordplay.
I cannot quite understand how this works, but
'finally' could be 'last' ('last' can be a synonym of 'finally') and 'last' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'used' acts as a link.
(Other definitions for sandblast that I've seen before include "clean building?" , "Roughen, clean (with jet of fine particles)" , "Clean with abrasive jet" , "Clean by using jet of grit" , "Finish a surface by attacking with small grains" .)