Door Slab The outer layer of the door slab is of tough tested quality M.S. Plate of 12 mm for Class-C and 30 mm thickness for Class-B door as per IS: 11188(1991). It is further reinforced by a composite 70 mm thick layer of double duty barrier material and layers of flame and arc resistant (special) alloy which provides dependable protection again fire and attack of power drilling, oxy-acetylene flame and arc cutting. This dual protection is provided over the entire lock case. The total thickness of protective layer is 90 mm for Class C and 105 mm for Class B.

Door Frame Tested quality 10 mm thick M.S. plate is used for fabricating the one-piece bent angle door frame. For strength and rigidity the door frame is suitably, reinforced along the height and width. A special ‘Box-jamb’ is welded to the frame to provide strong rebate for the shooting bolts.

Bolt Work And Locking Mechanism The door is provided with 12 shooting bolt (each of 38 mm dia.) six in front, six at the rear, which slides behind the tough ‘Box-jamb’ rebate. These bolts can be activated simultaneously by the movement of handle. Any pressure exerted on the lock bolt on one side automatically bring into play equal balancing pressure on the opposite side to neutralize and defeat the attempts to dislodge the lock. The doors are fitted with two superior quality dual control precision 10-lever locks along with S.S. keys in duplicate. At extra cost, if specified at the time of placing of the order, 3 or 4-wheel numerical combination lock which offer nearly 100 million combination for setting and resetting can be provided or superior quality imported Time Lock with multiple clock movements can be fitted.

Automatic re-locking device A standard feature on all models of door, this sensitive device is triggered-of when an attack is attempted on the lock through the keyhole with any instrument. This automatic re-locking device guards all the key locks.