Today we are going to talk about one of the most useful tools on our jeweler's bench... Calipers! These are the calipers we use at the studio:  6" digital calipers Uses: Depth and diameter of stones. Checking bur sizes. Inside diameter of rings. (you need to be able to create the correct size ring. Scribe for straight lines. Know the thickness of your metal. Know if you filed your metal straight by holding them in. Drawbacks: Convert to inches and can easily hit the convert button. Easy to accidentally hit the zero out button ...