Preheating of the billet and extrusion die takes place before the actual extrusion process starts. The essence is to soften the billet to allow it to be forced through the die?
Ornamental Iron fences are actually made of steel. They are cheaper to buy, easier to produce, and are widely available. It’s easier for consumers to modify their wrought iron fences after installation. Many fence manufacturers also use wrought iron to put the finishing touches on an ornamental iron fence through casting or similar processes.