Case Study: Frame Chassis

Process: Metal injection molding (MIM)

Material: 17-4 PH stainless steel

Density: 7.6 g/cm³ minimum

Hardness:36-42 HRC

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End Use and Function

This component is a frame chassis used in a pistol. The frame chassis holds 7 parts in its subassembly. Over 100,000 frame chassis are required annually, with the ability to increase production when demand increases.

Fabrication

Maintaining the slide matching in manufacturing and assembly required zero flash during molding. To achieve the part with zero distortion, the proper furnace setters were required. To reduce post sintering machining operations, no supporting ribs or supports were utilized. The part required a straightness within 0.2mm (0.008 in) with respect to outer thickness. The MIM-17-4 PH stainless steel material required an H900 heat treatment to meet hardness requirements.

Results

Prior to MIM the parts were machined from bar stock by the customer. The MIM parts meet 80% of the required part features with the remainder being machined by the customer. This reduced the machining cycle by 70%. With over 500,000 parts shipped, the performance of the MIM parts has exceeded the customer’s quantity and quality demands, while being a cost-effective solution.