"iron box" is a perfectly acceptable phrase in written English.
You can use it in a variety of contexts, such as: "I placed the jewelry in an iron box for safekeeping."
Each diorama is enclosed in a 2 ½-ton iron box.
I would much rather have them sitting in an iron box for the rest of their lives, contemplating their ignominy".
In his new universe, he and 50-odd strangers shared a partly submerged iron box that was 12 feet high, 36 feet wide, and 127 feet long.
Gardai are studying CCTV footage of people entering the cathedral and detectives are investigating the theory that thieves may have hidden themselves inside overnight before breaking into the iron box once the building was closed to the public.
He outdid local religious leaders by showing that, seemingly through will-power, he could make even the strongest man unable to lift a small iron box that a small child could pick up.
We have constructed a pair of Quasi-Sheet dipole magnets, each an iron box enclosing Nd Fe B blocks that produce a 0.486 T field adjustable to ±2% and uniform to better than ± 0.05% in a 500×250×20 mm3 working region.
Shutters became closet doors; the weird iron boxes are now planters.
Six shoulder-high iron boxes went on display in the nave of Venice's Church of Saint'Antonin today.
This consisted of six huge iron boxes containing fibreglass depictions of scenes from his 81 days in a Chinese prison, complete with guards and cell-beds.
For "S.A.C.R.E.D.," Ai took over the Sant'Antonin church, where six large iron boxes serve as dioramas that document the 81 days he was jailed by the Chinese government in 2011.
The work consists of six hulking, iron boxes containing dioramas that show the indignities of imprisonment: squalor, surveillance and constant supervision.
