'Pillar' in the Bible

Today, I am the One who has made you a fortified city, an iron pillar, and bronze walls against the whole land—against the kings of Judah, its officials, its priests, and the population.

One pillar was 27 feet tall, had a circumference of 18 feet, was hollow—four fingers thick—

and had a bronze capital on top of it. One capital, encircled by bronze latticework and pomegranates, stood 7½ feet high. The second pillar was the same, with pomegranates.