Construction workers (4-4)
There are a few possibilities for this:
hard-hats
'construction workers' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for builders that I've seen before include "Constructors" , "Construction workers" .)
'construction workers' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Another definition for hardhats that I've seen is " As worn on building sites".)