How to Machine a Taper on a Steel Pin

Place the steel pin into the spindle jaws so approximately ¼-inch of the steel protrudes from the key. Tighten the steel in the jaws with the chuck key. While gripped in the chuck, the steel will spin true.

Secure the drill attachment into the front of the tailstock. Place a center drill into the drill attachment.

Set the lathe at 300 rpm and turn it on. Drill approximately 1/8-inch into the end of the steel pin by turning the handle on the tailstock clockwise.

Stop the lathe and remove the steel pin. Place the steel pin with the other end protruding. Drill a 1/8-inch deep hole into that end of the pin.

Remove the drill attachment from the tailstock. Insert a “live center” with a bearing in it that allows the center to spin with the steel pin.

Remove the steel pin from the jaws of the spindle. Grip a “dead center” into the jaws. A dead center forces the steel rod to spin with the spindle.

Place the hole in one end of the steel rod against the tip of the dead center. Slide the tailstock so the tip of the live center presses into the other hole. Lock the tailstock in place with the lock lever.

Set the tailstock tape adjustment to rotate the front of the tailstock away from the turning tool, which is attached to the turret on the lathe. When the tool cuts, the tailstock will force the steel rod to spin “out of round,” causing the turning tool to cut the end of the steel rod closest to the tailstock at a smaller diameter. As the tool moves toward dead center, the diameter of the steel pin increases.

Set the feed rate to a rate suitable for turning steel. Use the chart located on the lathe for your specific model.

Turn on the lathe. Engage the automatic feed to run the turning tool across the metal surface of the steel pin. Stop the automatic feed once the tool passes over the metal surface. This creates the taper in the metal surface.