Shoulder turning is also known as step turning operation. When a workpiece having different diameters is turned, the surface forming the step from one diameter to the other is called the shoulder, and machining this part of the workpiece is called shoulder turning. On the work piece material with different diameters are used for the performance, at that instance shoulder turning operation is used. There are different types of the shoulder turning they are beveled shoulder, radius shoulder and squared shoulder.
Three common types of shoulder:
- Filleted corner
- Angular of Tapered
- With a workpiece mounted in a lathe, lay out the shoulder position from the finished end of the workpiece. In case of filleted shoulders, all sufficient length to permit the proper radius to be formed on the finished shoulder.
- Place the point of the tool bit at this mark and cut a small groove around the circumference to mark off the length.
- With a turning tool bit, rough and finish turn the workpiece about .063 inch of the required length.
- Set up an end facing tool. Chalk the small diameter of the workpiece, and bring the cutting tool up until it just removes the chalk mark.
- Note the reading on the graduated collar of the cross-feed handle.
- Face square the shoulder, cutting to the line using hand feed.
- For successive cuts, return the cross-feed handle to the same graduated collar setting.
If a filleted corner is required, a tool bit having the same radius is used for finishing the shoulder. Angular or chamfered edges may be obtained by setting the cutting edge of the tool bit to the desired angle of chamfer and feeding it against the shoulder, or by setting the compound rest to the desired angle.