I think the largest socket I used on our BH was 1 1/16" to remove the water heater element. Sure, you can get that cheap "socket" with a rod for removing them, but I found it a bit too short with the stuff on the face of the water heater. A socket drive with an extension gives more torque than that did. Other than that, the next larger 'nut" was the water heater drain plug/anode rod.