Dan_Musicant wrote:

1. The embedded steel filings will add strength just by virtue of the
toughness of the steel.

2. Having a lot of rough surface area of embedded steel particles will
add to rather than diminish the toughness of the glue in resisting
breaking loose.

Adding steel particles will not increase the strength or toughness of epoxy. It
can increase the abrasion resistance of the epoxy and can change the working
characteristics (from liquid to paste).

Tensile strength will rely entirely on the epoxy. Compressive and shear
strengths might be greater if the density of the steel particles is quite high
(much more steel than epoxy) and the epoxy just acts to keep the particles in
place. Otherwise these characteristics won't be affected much.

Abrasion resistance will be increased since the epoxy will abrade from the
surface and the steel particles will take the wear.

Mike