A Blockhead can wear iron armor leggings by dragging the item into the Blockhead's clothing slot for pants. The Blockhead then takes a reduced amount of damage (better than the reduction tin produces). Iron armor leggings will wear out naturally, but wear out even faster when the wearer is taking damage from creatures or other players.
Iron armor leggings resemble tin armor leggings, but have a slight grey tint instead of a blue tint. They also resemble linen pants and leather pants, but are metallic and tinted dark grey instead of white or brown, or any dyed pants.