A comparatively small flange, step, or overhang can often be produced by machining a shelf or step in the die. Too large a flange causes ejection difficulties. Bottom flange edge and juncture radii should be generous.
Boss-forming cavities may be located in punch tools. Cavities may not be too deep in relation to part height (15% less) and draft angles should be at least 12° per side to avoid sticking of the compacted boss to the punch.
Hubs, which are complementary part sections to gears, sprockets, or cams, can be readily produced by the PM process. It is important to include a generous radius between the hub and flange section and to maximize space between the hub O.D. and the root diameter of the gear or sprocket.
While studs with drafted sides can be made like bosses, sometimes no draft is allowed or the stud-to-diameter ratio is relatively large. In that case, tooling with additional punches is required. Always consider the fragility of the green compact prior to sintering.