Designing for MIM
There are various advantages to looking at the part design from a metal injection molding perspective. For example, features not available in other technologies can be incorporated in part design, and often assemblies of multiple parts can be designed as one part.
Cost advantages can be achieved by considering the following during the design phase:
- Lettering and Logos
- Hexagonal, square, blind and flat bottom holes
- Stiffening Ribs
- Lightening Holes (Coring)
- Through Holes
- Webs and other special features
- Protrusions and Studs
- External Threads
- Internal Threads
Desirable Features of MIM/CIM Designs:
- Gradual section thickness changes
- Symmetrical slots or holes
- Largest dimensions below 12 inches
- Wall thickness under 1 inch
Contraints of the MIM/CIM process:
- No inside closed cavities
- No undercuts on internal bores
- Corner radius greater than .008"
- 2˚ draft on long parts (0.5˚ minimum allowable)
- Parting line consideration
- Mold ejection method (pin placement)
- Smallest hole diameter to date .008"
- Minimum wall thickness .006"
- Minimum part weight sub-gram
- Maximum part weight (no theoretical limit)