JoeSpareBedroom wrote:

Just picked up my newly sharpened blades from the mower place. The repair
guys said "Make damn sure you tighten the bolts right. There's no way to get
the required 40 ft/lb torque with a 3/8" drive. With a breaker bar, yes, but
not with a 3/8 torque wrench." I have a 3/8" drive Matco torque wrench with
adjustments from 10 to 100 ft lbs. It's 18" long, bigger than any breaker
bar I have.

What's this repair guy talking about?

I'm guessing he either thought the bolts would go into aluminum
threads that couldn't take any higher torque, or you wouldn't have
anything to hold the blade in place while tighting the bolts and would
be relying only on engine compression to resist the tightening.