(b) Minimizing Machining
To minimize machining of the casting shown in partial cross-section in (a), relieve base, leaving only a peripheral bearing area; and design upper surface so that machining is limited to circular ring sections around holes (b). Finish machining of the ring section involves simple counterbores, rather than milling or grinding.

The amount of drilling of a long hole (a) for guiding a reciprocating rod can be reduced by the cutout shown in (b), relieving the central portion of the bar without impairing its function.

To reduce the machining required in design (a), the heights of the three projections, which are to be machined, should be equal, if possible. They should also be lined up horizontally in order to minimize the width of the machining operation.

If the surfaces to be machined cannot lie in the same plane (a), at least they should be parallel (b).

When machining two shaft diameters, the square shoulder requires a special setup or a separate squaring tool (a). A tapered shoulder (b) can be produced by the same tool used for turning.