Your knife converting itself to iron filings like that probably is indeed due to one of the components being much softer steel than the other, and if I had to hazard a guess I’d say the blade steel is probably much harder than the backspacer. The latter may not even be hardened at all.

If you really gave a rat’s ass you could attack both of them with one of those graded hardness file sets and figure out which one is softer, but that’s probably putting pearls before swine given that even a knockoff set of one of those is around ten times the cost of this knife. Other than pure curiosity I don’t think there’d be much benefit, and nothing you learn would be any more functionally useful than already knowing that this thing is apparently crap.

That point profile is the worst I have seen in a long time. It’s almost an achievement all by itself in how awful it is. I’m almost feeling nostalgic over it. It’s just like I’ve gone back to when I was a lad, pawing over the rows of lousy Pakistani cutlery on the tables at the local flea market back in the day.