221 - 221 double nightlatch with key lock-back


Locks for classroom doors, offices, industrial premises, apartments, etc.

Available with single cylinder and thumbturn, or alternatively with double cylinders or single cylinder only.

Supplied as standard with striking plate.

Cylinder and accessories bolt through lockcase for added strength.

Key can only be removed in locked (or locked-back) position.

For finishes and dimensions see Lockcases Information appendix.

When ordering please specify hand and door thickness.


Upper bolt deadlocks automatically when door is closed. Key for locking the upper bolt into lockcase. Lower bolt operated by lever handle. Bolts reversible without opening lockcase.

Available with 35mm, 50mm or 70mm backset.

Optional microswitches: MF monitors bolt deadlatching and use of cylinder/thumbturn MD monitors lock-back.


Upper latchbolt automatically deadlocked. 

Key retracts both latchbolts. Lever handle retracts lower latchbolt


Turn retracts both latchbolts. Lever handle retracts lower latchbolt.

Upper latchbolt held back by key in faceplate.



Product has been successfully type-tested for conformity to BS EN 12209.
Regular audit testing is undertaken.