For very large bolts (example: axle nut) I often see mechanics just use an impact wrench, typically they let it "rattle" a certain time and then they consider the bolt tightened. Is this also common/considered acceptable practice in other shops/locations? For smaller bolts or applications like head bolts, alloy rims and other delicate stuff I am 100% sure that you need a torque wrench and taking shortcuts leads to disasters, but on real massive bolts I am inclined to consider the mentioned practice to be alright (within certain limits).
Why I am asking this question:
The axle nut on my Astra H demands 250NM, my larger torque wrench has a range up to 200NM, so I cannot use it for this job. I do not want to buy a wrench that goes slightly over 250NM, because then I would have bought two wrenches with mostly the same range. An expensive alternative would be a 3/4" wrench, so I would be prepared for future tasks, but it seems to be overkill, also financially.
I am quite reluctant to spend a lot of money on tools just for the axle nut, also I do not think that I will be using it often. The axle is a M22 fine thread, the nut is self locking, the bearing is in an integrated unit and already pre-loaded. Should I buy a matching torque wrench or just bash the nut on with the impact wrench ?