Tools engraved for NASA have to be permanently marked so the information cannot be removed. To achieve this we use a cnc machine with a carbite cutter spinning at 34,000 RPM’s to machine a very small groove .005″ to .010″ deep by .020″ wide. Sockets are hardened steel and tend to wear out cutters at a rate of about 10 to 15 sockets per sharpening. The other problem engraving tools is they are all different sizes and shapes, therefore a constant adjusting of equipment and holding methods are necessary. Some are quicker to engrave using a manual pantograph, some quicker on the cnc.