Brickie's tool and mask from metalworks (6)
I believe the answer is:
trowel
'metalworks' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for trowel that I've seen before include "Small tool for scooping or spreading" , "Plastering tool" , "Small spade" , "Small triangular tool for weeding in garden" , "Small garden hand-tool" .)