I use a scribe a lot. I keep several around the shop. I saw one on the internet the other day and new I had to have one, so I made my version. It is about 5 1/2 inches long when open and 3 inches closed. It is made of brass and the point is hardened drill rod. It is made entirely on the lathe and would make a good beginner's project that is useful. I'm making a couple more for machinist friends for Christmas. I have a print on my web site but you really don't need one all the dimensions can be made to suit you. The pictures shoul tell you enough to whip one up in a few hours.
Mark Frazier
Mark Frazier