Besides "råskinn, hardhaus, harding, tøffing and barsking, and tøff type", there isn't much else to dig up. Yoy can use tøff fyr and hard negl to say the same thing with a furrin' twist, and hard fyr if you want to enter a slightly pornographic angle into the equation.
It's really kinda funny that tough guy seems to have about eleventeen different permutations in Norwegian, when it's really the other way around - there must be a dozen US EN expressions that would inevitably end up as the lame 'tøffing' due to the lacking richness of the Norwegian street slang.