This part depends on the batch, and the bar car is used in small batches, but the cost is very high, so the possibility of scrapping should be considered.

It is recommended to use a large number of stainless steel tubes. Stainless steel pipes with an outside diameter of 12 and a wall thickness of 2.5 shall be used. According to the length, leave a margin for blanking, and turn out the wall thickness of 7.8. The bottom is cut with 12 bar lathe or milling machine. After argon arc welding, grind the excircle with a knife.

Because I don't know other technical requirements, I just consider it according to the appearance.

Personal experience for reference. Questions and discussions are welcome. Thank you.

One more thing to add: It can be inferred from the dimensions of 1 1.8 and 7.8 that the processing method considered by this designer is steel pipe, because it is very suitable to use steel pipe with external circle 12 and wall thickness of 2.5 as these two dimensions. In mass production, it is very efficient to roughly grind a knife after welding and then put it on a centerless grinder.