Ewan MacColl's song "My Old Man" contains the lyrics:
My old man was a good old man
Skilled in the moulding trade
In the stinking heat of the iron foundry
My old man was made
Down on his knees in the moulding sand
He wore his trade like a company brand
He was one of the cyclops’ smoky band
Yes, that was my old man
Who was this cyclops, and what was his smoky band?
In the work of the Greek poet Hesiod, the three cyclops,
Arges, Brontes, and Steropes (Bright, Thunderer, Lightener)—[...] forged the thunderbolts of Zeus. Later authors made them the workmen of Hephaestus and said that Apollo killed them for making the thunderbolt that slew his son Asclepius.
This would be the connection which led to the naming of the Sheffield ‘Cyclops Works’, that @GarethRees cited in comments, but which equally applies to all foundry men.
Working molten metal is a dangerous trade, sparks fly and no doubt the classical link of one eyed creatures with foundry work reflects a tendency of those in that trade to lose eyes, particularly before glass eye protection became possible and common.
The song also contains the line
They'll rob you blind if you don't fight
Which makes me wonder if his father had his eyesight damaged by the work. But even if not, cyclops were iron shapers to the Gods, Pa MacColl was one of their trade, and foundries are smokey places.
