Unipart rant

[C2K]

1/2 breaker bar for a hub nut? maybe 3/4 your asking a bit much for the 1/2 bar to get to 325nM

Not at all, look at the capacity of a half inch torque wrench. 450Nm is the approximate limit for half inch, providing you're using quality tooling. Had to do it before with no choice.

I've cracked mine before with my 1/2 halfords breaker bar. I have used 3/4 before and it's much easier, but now I have a 1/2 Impact gun anyway.

Impact principle with a breaker bar works wonders. Sit an axle stand in front of it to hold your socket/extension ready to go and jump on the bar.