Here’s how to make a seamless cup or dish thingy .
This could be used to make a locket or pendant or just a nice thing to waste your time on a Saturday afternoon, like I often do.
Basically you need two rods of steel the same diameter and in this picture I used some scrap brass.
Then the brass is aligned up like in the picture.
And clamped in the vice like this.
Then the outer lip is tapped over using a punch like this.
Here is a picture of the piece half formed.
Tapped all the way over.
Then I took a piece of 1 mm titanium and did the same thing.
So then I decided to see if a square would work.
Logic told me the corners would tear.
Weird thing is they didn’t, but formed little horns.
So after the brass was trimmed I did the same for titanium.
Naturally the titanium was a bit harder and I annealed it a couple of more times than the brass but it worked out OK.
One titanium dish, ready to serve a very small salad.
Now it stands to reason that one could make pretty much any form is steel and then make a seamless bowl, given enough taps with your punch.
So I am quite chuffed that it worked, because it’s another piece of useless information that I can store in my mind’s dusty attic.
Actually, I can see this method could be used to make gem stone collets or odd shaped tubes in difficult to solder metals like titanium.