OK, Doug Campbell and I have been emailing a little about domed pins so I thought it might be good to show some pics of how I do it. Maybe after a bit, Doug or Karl can add some to this.
There is really nothing complicated about it. First I will show you a knife that I recently made with domed pins and then show you how I made the pins.
I did not want the domes of these pins to directly apply pressure to the ivory. So I made some washers to sit flush and let the pins push down on them to distribute the pressure. So I had to make, not only the washers but the tool to set them into the ivory. I already had some pinstock of a certain size and I hade a disc punching block from a past knife so I needed to make the tool to work with those dimensions. Here is the tool. It's out of mild steel rod 1/4 inch.
I messed aorund and filed it left handed, but that is no problem. It works the same in a reversable battery drill. The hole that's drilled first and the guide on the end of the cutter is the same diameter as my pins stock. The guide may be a gnat hair smaller to keep it from getting hot.
I only went in enough to insure I had good thickness on my washer after smoothing off the top and evening it out with the surface of the ivory. I did not want to remove any more ivory bark than I had to, since it has the nice colors. The washers were 1/16 thick, so the inset was slightly less than that. I just eyeballed it.
Let's say the washer is in place and the pin is cut and in the hole protruding a little beyond both washers. If the pin is 1/8 inch in diameter, the length should be sticking out about 1/16 on each side. Some materials will let you get away with more, but stainless wont. I used fine Silver here so I went a little more for a bigger dome. Stainless will split at the edges of the dome if you try to move it too much. I dont have good pictures here but I do have a short video of a student doming a pin the way I do it.
Doming of pin with ball pein hammer Light blows are important and polish the ball on the hammer before you hammer it. It will buff out better. Most of the time, I dont want the buffer to get on the handle material so I wrap it in painter's tape and using my fingernail, I cut around the pin and remove the plug exposing the pin head. This will allow you to buff the pin. Be sure and start light and only get more agressive if needed. Also, buff from all directions. The head is round and it will stay round by buffing toward it from all directions. Here is the taped handle.
That's about it. Sorry for the blurred pics, but the cell phone has allowed me to access a camera when otherwise I would not.