General criteria
Comparison with other technologies


Tolerances
The dimensional tolerances permitted by the system depend above all on the size of the part; a smaller influence is exercised by the shape, material and position of the gate. Furthermore, with a suitable redesign of the part, and given the production process itself, it is possible to assign a high level of confidence to some of the design specifications and thus make selected controls during final testing.
For example, during the high temperature phases of the process one must guard against deflections, which can be caused both by the thermal cycle and the shape of the part itself. Special attention must therefore be paid to the design of the masses perpendicular to the supporting surface, and those near to the gate.
Distortions can be minimized or eliminated, as well as by specifying suitable thermal cycles, by providing large supporting surfaces capable of supporting the masses and facilitating their retraction in the correct manner (14%). Gravity is a significant factor during the high temperature phases, during which the part may be vulnerable to structural collapse. Masses which are cantilevered relative to the central body may thus risk collapse if not adequately supported: the support may be provided externally (ceramic supports) or integrally to the part during redesign (such elements can be left on the finished part or machined away subsequently). Another element to be considered during design, and which affects the quality of the individual MIM, is the concept of adding mass only where it is functional. Material thus need not be machined away, but is rather added where it has a concrete function.



Borings
Threads
Uniform cross-sections
Injection
Surface finish
Assembly of green parts
Materials
Mechanical characteristics