They are now made of steel, either Bessemer steel or open-hearth.

Bessemer steel was being displaced by the open hearth furnace near the end of the 19th century.

This bridge was constructed from Bessemer steel, which proved too brittle and so the bridge was replaced again in 1898.

The first Bessemer steel made in the United States was at this factory in 1865.

Most of it went into the manufacture of Bessemer steel and was much sought after by steel manufacturers.

They started the production of Bessemer steel in 1865.

The primary causes were the increasing competition from Bessemer steel and workers' demand for higher wages.

By the end of the 19th century, basic Bessemer steel had reduced production costs by 90% compared to the puddling process of the midcentury.

The firm manufactured Bessemer steel and railway tracks.

By 1870 Bessemer steel was widely used for ship plate.