Square Shoulder.docx

Experiment # 7 Objective: To turn a square shoulder on lathe machine

Apparatus: Lathe machine

Theory: Turning is the removal of metal from the outer diameter of a rotating cylindrical workpiece. Turning is used to reduce the diameter of the workpiece, usually to a specified dimension, and to produce a smooth finish on the metal. Often the workpiece will be turned so that adjacent sections have different diameters.

PROCEDURE 1. A shoulder is a point at which the diameter of the work piece changes with no taper from one diameter to the other. 2. In other words, there is a 90 degree face moving from one diameter to the other. 3. To get a nice square edge it must be machined with a tool having sharp point. 4. It should be ground to an angle of less than 90 degrees so that it can work right down into the corner of the shoulder. 5. To get a nice square face on the shoulder it will be needed to make a facing cut. 6. While doing so the carriage should be locked. 7. This gives the best result. Face of the shoulder should be cleaned up by locking the carriage until it is square. 8. While using sharp pointed tool it will needed to use fairly high RPM, say 1500, and advancing the tool slowly otherwise it will get little grooves from the pointed tip instead of a nice smooth finish. Finally, sharp corners are to be removed by using a file to make a nice beveled edge on outside edge of the shoulder and on the end of the work piece.