Each year Sherline machines and accessories are being purchased for use in fields and areas other than their intended use. One of these areas is laser engraving.. Sherline designed our Pin Jaws specifically for laser engraving rings and other similar parts. These jaws are not designed for machining parts or other uses that require more than finger tight closing pressure to hold the part in the chuck. Round parts can be held from the inside with just finger-tight grip of the pins while the outside is laser marked. The jaws will work in any of our 3-Jaw Chucks.. Sherline recently improved the design of the pin jaws. The hole that holds the pin now goes all the way through each jaw so you can easily knock out any broken pins.