Auron kept on heating the furnace. When it was hot enough, Auron began his works. He brought the iron mold and cooked it inside the furnace. During the hammering process, two things were affecting the process.
First, the blacksmiths' attributes. Three attributes affect the hammering process, strength, agility, and luck. All of the blacksmiths would have the same initial hammering speed. To increased the hammering speed, they needed to depend on their strength and agility.
The time limit which the blueprint gives is only for the hammering process.
Meanwhile, the examination three hours time limit was given for the material selection and hammering process