Large-end head processing has traditionally been done using hot forging forming technology. It requires high-power, heavy-duty presses and corresponding upper and lower forging dies. Manufacturing a large-end head forging die is expensive, with a long processing cycle, weighing several tens of tons, necessitating heavy-duty crane lifting equipment, and is not convenient for transportation. Moreover, its utilization rate is low, hence the high cost of large-end head processing. Clearly, this is one of the main drawbacks of hot forging for manufacturing large, medium-thickness end heads. For medium-thickness end heads, within the equipment's manufacturing capabilities, various shapes such as elliptical, dish-shaped, and more, do not require forging dies, which can reduce costs and overcome the drawbacks of hot forging forming. Therefore, their processing costs are lower than hot forging, which is one of their main advantages. The aforementioned large-end heads were formed using a hot spinning machine. The following is an introduction to its forming process.

Large blank head hot forming process includes large blank head spinning forming, which is divided into three types according to the forming temperature: cold spinning (room temperature), warm spinning (<120℃), and hot spinning (>800℃). Since the 1970s, cold spinning forming has gradually expanded its use domestically, but it is only suitable for large blank heads with a plate thickness of 30mm or less. Large blank heads thicker than 30mm are difficult to form and require hot pressing or hot spinning forming processes.