Bessemer Steel Ingot

Mild steel blown from molten iron in the Bessemer converter.

The route into it is the converter's own pour, not a mold you fill from a bar: a tool mold or an ingot mold dipped in a molten canal running Bessemer steel drops the Bessemer version of what that mold makes. It cannot be hammered on an anvil; the metal is kept off the vanilla list on purpose, so there is no work item for it. It melts back to itself at 1500 C, but nothing in siex or Iron Industry Expanded has a recipe asking for it, so today it is metal with nowhere to go but a mold.