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 DRILL BITS
Center drills are used with the lathe to drill a hole in the end of stock for mounting between centers in the lather         

Center Drill BITS

Center drills are used with the lathe to drill a hole in the end of stock for mounting between centers in the lathe. They are designed to drill a small diameter pilot hole followed by a *0 degree countersink that provides a bearing surface for the *0 degree point of the lathe center. Center drill are also used extensively with the milling machine to accurately start holes. The hole locations can be dialed in using the milling machine's calibrated hand wheels, then the hole is started using the center drill. The large diameter shank on the center drill holds the drill point right on center, Once the hole is started, the center drill is replaced with a drill of the desired diameter and the hole is finished. It is imperative hat a cutting lubricant is used, and the center drill is backed off several times to prevent the tip from twisting off.