In the previous cap structure design, the shape of cone clamping elements is usually designed as a smooth cone structure. However, with the increase of civilian rocket types and the expansion of application fields, the shape of the hood changes accordingly. 

The common structure is to increase the flight resistance of the missile body, and the resistance ring groove is usually designed at the head of the hood. Due to the change of the hood structure, it is impossible to process the resistance ring groove by using the previous stamping and drawing technology. 

It is necessary to realize the forming of the ring groove by means of machine addition in the subsequent processing process.