Another case history Involved a shaft in which a locating ring and set screw (a) were replaced by an external, split retaining ring (b)

For retention of a spring a special screw and tapped hole (a) has been replaced by an internal retaining ring (b).  

Another method of replacing a stepped shaft with several diameters (a)--in this case with a single shaft threaded at one end to receive the matching bushing. Design (b) involves less metal removal and less machining, except for the added thread.  

The advantage of a one-diameter construction is even more pronounced in the case of internal boring or drilling. Instead of boring from two sides (two setups, requiring close alignment) as in (a), a one-diameter bore with an insert is preferable. The insert can be in the form of a bushing (b), or two split retaining rings (C).   

A specific illustration of the preceding principle: the ball-bearing housing design (a) is simplified considerably by means of the composite construction consisting of a one-diameter bore and split retaining rings (b).

A one-piece construction with an internal broach (a) can be replaced by a one-diameter bore into which an internally broached bushing is press fitted (b). Machining costs are significantly reduced in this way.