The nut is the slim piece on the headstock that holds the strings above the fingerboard, and is the last point of contact before the tuning machines. With a floyd rose, you'd have a locking nut which tightens down. Now as far as heavier strings breaking it, yours is prolly made of metal, so I wouldn't worry about that. Yet they (the strings) still might not fit the slots. I'm not saying don't try em...you should experiment. But if they play with a buzz or are muted, start by looking at your nut slots.



(My experience was with a cheap plastic nut and heavy strings that caused the edge to break off.)