Steel Ingot is used in a number of recipes. It is an alloy ingot.
Steel Ingot could be used a Beacon payment.
Steel Ingot is used in the following Crafting Table recipes:
Compressor recipe:
Steel Ingot → Steel Plate
Grinder recipe:
Steel Ingot → Steel Dust
Blast Furnace recipe:
Steel Ingot + Tungsten Ingot→ Hot Tungstensteel Ingot + Dark Ashes Dust