Abstract: A safe door assembly comprising a door casing, a door, a plurality of locking bolts operated by a combination lock so as to be selectively extended outwardly from or retracted inwardly into said door to lock or unlock, respectively, the door to the casing; the casing including a seat to accomodate a shoulder on a door and a recess to receive each of the outwardly extending locking bolts, the door having a combination lock with a retractable tongue directly connected to one locking bolt and also connected via a sliding link bar and lever means to the remaining locking bolts in such a fashion that all bolts extend and retract simultaneously; a pivotable relocking bar spring biased to pivot into a position which prevents movement of the sliding link bar and thereby prevents retraction of the locking bolts when the combination lock is displaced inwardly from its normal position; the assembly also comprising a hardened steel barrier protecting the outer extremities of said locking bolts from access by a drill, a h