SEM images - cross section of MIM and bar stock (cast?) 1911 thumb safeties.
Many manufacturers are using MIM parts in their pistols. I was curious to see if there are any obvious internal differences between MIM and bar stock parts so decided to cut up a pair of thumb safeties, one from Ed Brown and one from Kimber. I cut off the pin that passes through the frame and these images are looking at the cross section of those pins. I started at the outer edge and moved inwards towards the center. The Kimber MIM thumb safety is blued or painted but based on the EDXA (energy dispersive x-ray analysis) results, it could be stainless since it contains almost 11 wt% chromium and almost 3 wt% nickel. The Ed Brown thumb safety contains less than 1 wt% chromium and no nickel.
Ed Brown thumb safety - bar stock or cast
Kimber factory MIM thumb safety from a TEII
Many manufacturers are using MIM parts in their pistols. I was curious to see if there are any obvious internal differences between MIM and bar stock parts so decided to cut up a pair of thumb safeties, one from Ed Brown and one from Kimber. I cut off the pin that passes through the frame and these images are looking at the cross section of those pins. I started at the outer edge and moved inwards towards the center. The Kimber MIM thumb safety is blued or painted but based on the EDXA (energy dispersive x-ray analysis) results, it could be stainless since it contains almost 11 wt% chromium and almost 3 wt% nickel. The Ed Brown thumb safety contains less than 1 wt% chromium and no nickel.
Ed Brown thumb safety - bar stock or cast
Kimber factory MIM thumb safety from a TEII
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