This is a 2” boring head I made using my lathe with my homemade milling attachment. I believe the body is made of 1144 Stressproof. It’s from a bar that was thrown out at work because it wasn’t marked what it was. It cuts like 1144 so I’m just assuming that’s what it is. The screw is made of 4140 PHT and the hex in the adjustment dial is the head of a 1/4” SHCS press into it. The shank is 3/4” and it holds 1/2” boring bars. The graduations on the dial were cut in with the compound and a tool bit. A paper template sandwiched between 1/8” plexiglass and a pointer were used to index the graduations on the dial.