About the use of the term "galling". My use of the term is based on wear features that are reported, and the interpreted materials at the interface, i.e. some form of hardened stainless steel and some form of hardened aluminum alloy, and interpreting that the surface hardness of the stainless is greater than the surface hardness of the aluminum alloy (except for the aluminum oxide layer that forms naturally, but is quite thin). The reported wear is occurring to the frame material, and, ostensibly at an interface which should be designed as a flat bearing surface (to distribute design sliding load), so, if wear is occurring to one [flat interfacing] surface, and the appearance of the wear is "scratching", I would propose that the scratch appearance is due to a galling event whereby a particle of aluminum material becomes bonded [dynamically] to the stainless steel, under pressure and heat of friction, and subsequently "scratches" the softer aluminum frame material during slide movement subsequent to the galling event.
