The production cost of cold heading dies for internal hex bolts and external hex bolts may differ depending on various factors, such as:

  • Design and manufacturing cost of the dies: Internal hex bolts and external hex bolts have different shapes and sizes, which require different die designs and manufacturing processes, affecting the cost. The difference lies in the head manufacturing process, as the head structures are completely different and require different dies and processes. The head manufacturing cost of internal hex bolts is higher than that of external hex bolts due to the different head structures, with the cost of external hex bolts being only half that of internal hex bolts.
  • Material cost: Internal hex bolts and external hex bolts may use different materials, which may also affect the cost. For example, internal hex bolts are usually cold-headed from solid bar stock, while external hex bolts are cut and machined from hexagonal rod stock.
  • Processing cost: The production process of bolts using cold heading dies may involve multiple processing steps, such as cold heading, cutting, forming, cleaning, etc., and the cost of these steps may also differ depending on the type and quantity of bolts.

Therefore, when determining the production cost of internal hex bolts and external hex bolts, it is necessary to consider the above factors.