The first step it to remove all the scale (oxidized steel) on one end of the piece and turn it into a cylinder. Mount the piece into a 4-jaw chuck (each jaw is individually adjustable so it can hold irregular shaped pieces) and center it on the lathe.
First we make one end smooth and perpendicular so we can weld on a mandrel and then and we begin to round the piece into shape.
Now that we have a cylindrical end, we can finish making the entire piece of Damascus a cylinder.
Mounting the piece into a collet chuck, we put it back on the lathe and turn as we did before, removing the scale and rounding out the piece.
The finished product then is a solid cylinder of Damascus steel, flat on both ends ready to be shaped into a stopper.
