This heavy-duty chain consists of 5ft of 15mm round links made of hardened steel.

The cylinders, made of specially hardened steel, must spin fast, day and night, for months without wobbling or crashing.

Case hardened articles starting as low carbon steel can also be labeled hardened steel.

Engravers use a hardened steel tool called a burin to cut the design into the surface, most traditionally a copper plate.

Spinning tools can be made of hardened steel for using with aluminium or solid brass for spinning stainless steel or mild steel.