I need to hook up my neutral wire from a subpanel to the main neutral. The problem is there is no room at all for this install. Therefore I want to drill and tap a new lug on the main panel. 
Is there any requirement I should know about? Or design issue? What size screw would you all use? 1/4 20 with a lock washer that is threated in the neutral bar a good install? Could I use a smaller screw? That kind of stuff.
Thanks guys
	
		
			
		
		
	
				
			Is there any requirement I should know about? Or design issue? What size screw would you all use? 1/4 20 with a lock washer that is threated in the neutral bar a good install? Could I use a smaller screw? That kind of stuff.
Thanks guys
 
				
 
 
		
 
 
		