I was asked today, "How to set diamonds in a "pin-point" setting & the techniques involved". It's rather simple or should I say, easy! On my "Difficulty Scale" out of 10, I'd give this technique a definite 4.5 / 10.
The details of the setting, is that the mini-claws/prongs are rather small in height & width! I would start initially by under-cutting each claw with a 156C hart-shaped bur. No other bur shape is required. But you must first clean out the area of the hole for the pavilion to rest & the culet not to touch any metal!
Your bur cutting is low in the claw post, as you should make a bearing just where the girdle will eventually sit! Do not cut into the claw beyond 50% as the claw will too quickly move & subsequently break off!
At this juncture, place your diamond into the space allocated. Making sure the stones are all level and not crooked or tilted on one side. Get your bead-burnisher that has an opening slightly larger than the tip of the claws..as you want to push & burnish each and every claw as its be moved.. If there are only two claws per stone, great, this is going to be rather easy, why so? You will have less chance of actually tilting the stone.
The first thing you do is to gently push over the first claw, just enough as it will bend towards the stone. turn your project around and proceed to bend over the opposing claw!! This claw must now bend & actually touch the stone...Again, turn your project around to the first claw, then push that claw tight till it covers the diamond...tight...You are turning your project around many times in this project.
Examine your setting under a 10x power loupe all through this process. Each time your bead-burnisher is now "rounding & polishing" the tip of the claw as your are pushing over the claw!....VIOLA!
You are now done!
I once had a necklace with 1,260, 2mm stones This took me about 3 days as each 180-stone unit went on my shellac-stick...a real OY a.k.a Ouch! So sorry for the long detailed explanation, I love details!