no book in front of me, but i'd guess somewhere around 75lbs....lugnuts are more than that, but there is a place in the axle where you bend the inside lip of the nut into it with a punch....it won't come loose if you just tighten the shit out of it....can't strip it unless you've got crappy tools.....i've never torqued mine though....you can also use the temporary loctite
by the way, i've done at least 500 hundred jobs where i had to loosen/tighten it.....never a problem....get a breaker bar and tighten it until you bust a nut, or get an airgun with 125psi of air pressure and hammer the hell out of it...