Case Study: Coil Housing

Process: Conventional powder metallurgy
Secondary Processes: Resin impregnation and zinc plating
Density: 6.8–6.8 g/cm³

Coil Housing
2012 Grand Prize: Coil Housing

End Use and Function

This part is a soft magnetic powder metallurgy (PM) alloy coil housing used in a magnetic door closer for emergency/fire protection applications.


Formed as a single shape to a density of 6.8 to 6.9 g/cm³, the new PM design replaced a three-piece assembly. Critical design features include the locations of drafts, radii, and chamfers, as well as redefining tolerances for a near-net-shape part. Secondary operations include resin impregnation and zinc plating.
Extensive product design engineering was required to convert the three piece assembly into a single powder metallurgy friendly configuration.


The one-piece design provided a 21.5% cost savings over the previous assembly.
Conversion of a three-piece component into a single piece
Machining scrap reduced