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Appropriate parts for metal injection molding (MIM) depend upon a number of indicators including part size, shape, quantity, and the material properties required in the application. Appropriate parts for MIM have significant cost savings over parts made by other technologies. The most suitable parts for MIM are small, complex shapes made in high quantities where other methods are not feasible or not cost effective.
MIM PART SIZES	Typically less than 300 grams and have wall thicknesses less than 0.5 inch and more than 0.010 inch. Larger parts can be made successfully but costs rise and other indicators such as part shape or material properties must strongly determine the appropriateness.
MIM PART SHAPES	Allow complex features on three axes. Less complex shapes can still be justified when applications require smooth surfaces, good material properties and/or high quantities of parts in an appropriate size.
MIM PART TOLERANCES	Most economical if designed +/- 0.003 in./in. of dimension. However, tolerances as tight as +/- 0.001 in./in. have been achieved. On small dimensions tolerances of +/- 0.0005 in./in. can be held.
MIM DENSITIES	Range from about 95% to 99+% of full material density. Many materials are around 99% of full density because of special sintering techniques developed for them.
MIM PART QUANTITIES	Must be high enough to justify the cost of the mold and the up-front engineering to establish specific processing for the part. There is no one minimum appropriate quantity for all parts but quantities less than 2,000 parts are rarely economical unless they cannot be made by any other technology. Quantities between 2,000 and 10,000 parts need close scrutiny to determine the rational for appropriateness. Quantities over 10,000 parts usually can demonstrate good cost savings which increase as quantities increase. The highest part quantities offer the best cost benefits based on large material purchases, multiple cavity tooling, and dedicated production units.
MIM PART DESIGNS	Can often integrate two or more parts into one complex shaped part. This can produce economies not available by other technologies.
MIM MATERIALS	Include ferrous alloys, copper, stainless steels, iron-nickel, and iron-cobalt compositions. Materials such as aluminum, magnesium and zinc are not candidates for MIM because their low melt points allow die casting.
MIM PART PROPERTIES	Comparable to those of wrought products because of their high density and controlled microstructure. MIM parts can have properties superior to those made by P/M, die casting, and investment casting. MIM parts made from highly alloyed materials can even have properties superior to those of cast and wrought parts when segregation of the alloying elements is well controlled.
There are a number of indicators for appropriate MIM parts. Not all indicators must apply fully to realize cost savings over other technologies. However, all indicators are important in arriving at the rational to proceed with MIM and reaping the available cost savings.