Just the scale pattern on steel. The iron oxide reticulates upon itself .It’s something I look at everyday but I don’t usually notice it. Just below the roar of the forge you can hear the scale tinkle as it contracts and breaks note to self : Next time pull the steel out of the forge before talking to a walk-in customer. 🤦‍♂️...#blacksmith #ironoxide #scale #steel #forging #forgetting #redhot #frontstepforge | Front Step Forge