Frequently if one just gradually increases the torque applied to a fastener the head of the fastener will get damaged (esp. true with internal heads like allen, triple square and torx). IMO impact wrenches work so well because they apply high torque very quickly and also "hammer" on the fastener at the same time. That's also why I said to hammer on the fastener first---it also ensures that the wrench is fully seated on the fastener. Mark