These tools offer a blade and center drill on a head which can be adjusted with relation to the tool body. This lets you center the drill to the work in the spindle, thereby eliminating the need for grinding an “off-center” center on the drill. You can change these tools quickly and easily from right-hand to left-hand. Since they are self-contained, there are no extra parts to be lost. This flexibility makes it possible to cut down on your tool inventory, one tool serving a dual purpose. they are furnished with one hardened steel blade and one right-hand center drill.