Metal Injection Molding Tolerances

FeatureBest Possible ±Nominal ±
Absolute dimension0.025 mm (0.001 inch)0.05 mm (0.002 inch)
Hole diameter0.04%0.10%
Hole location0.10%0.30%
Perpendicularity0.1% or 0.1°0.2% or 0.3°
Surface roughness0.2 µm (8 µ inch)0.8 µm (32 µ inch)
Corner radius0.1 mm (0.004 inch)0.15 mm (0.006 inch)

Typically, tolerances of Metal Injection Molding fall within the range of ±0.3% to ±0.5%, a testament to the process’s capabilities in producing parts with exceptional accuracy. Nonetheless, the versatility of MIM encompasses a vast size spectrum, from minute features to more substantial elements, a range that poses a challenge in addressing tolerances uniformly. Recognizing this diversity, a pragmatic approach has emerged – a matrix of tolerance versus size, illustrating the nuanced tolerances achievable across the size spectrum.

For features measuring below 3 mm (0.12 inch), the attainable tolerance tightens to an impressive ±0.03 mm (0.0012 inch), reflecting the meticulous precision achievable on a miniature scale. As dimensions expand within the bracket of 3 to 6 mm (0.12 to 0.25 inch), tolerances remain stringent at ±0.05 mm (0.002 inch), underscoring the process’s consistent accuracy.

The transition to features ranging from 6 to 15 mm (0.25 to 0.6 inch) sees a slight relaxation in tolerances, aligning with ±0.08 mm (0.003 inch). The subsequent category, spanning 15 to 30 mm (0.6 to 1.2 inch), maintains the commitment to precision with tolerances of ±0.15 mm (0.006 inch). Finally, in the domain of larger components, those measuring 30 to 60 mm (1.2 to 2.4 inch), MIM demonstrates its adaptability, holding tolerances within ±0.25 mm (0.01 inch).

While the spectrum of MIM tolerances is presented here as distinct stages, it’s important to recognize the dynamic nature of manufacturing. Within a single production batch, the specified tolerances can indeed be achieved, exemplifying the process’s inherent capabilities. However, it’s worth noting that as time progresses, a slight increase in variability might be observed, a phenomenon often observed in manufacturing processes. This underlines the significance of ongoing quality control and optimization efforts in maintaining the desired precision over the long term.

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