4550 MS® Deadlock Lever

The 4550 MS® Deadlock Lever easily unlocks an MS® Deadlock with approximately three pounds of downward force. The spring-loaded lever relocks with an upward motion.


Easy unlocking of most MS Deadlocks by approximately 3 lbs [1.36 kg] downward force on a 3" [76.2 mm] lever. Lever is spring loaded to horizontal, relocks with upward motion. Indicator signals lock status. Can be installed in place of existing key cylinder or cylinder type thumbturn on inside of door. 4550 Deadlock Lever not compatible with 7/8" [22.2 mm] backset locks.


Rotate lever downward 90° to unlock. When released, lever returns to horizontal. Rotate lever upward 90° to relock. Key operation from outside is not affected. Clutching action prevents damage to internal components.


Housing: Aluminum casting is 1-3/8" wide x 7-1/2" long x 1" deep [34.9 mm x 190.5 mm x 25.4 mm].

Lever: 3" [76.2 mm] long aluminum with end-return design offers comfortable grip to lock or unlock.

Indicator: Words “LOCKED" in red letters or “OPEN" in green letters appear on white background when bolt is thrown or retracted respectively. Indicator is driven by lock bolt itself.

Stop Clearance: Lever housing projects 11/16" [17.5 mm] forward of cylinder backset centerline. Depending on height of door stop and width of door/jamb gap, it may be necessary to modify the stop to clear the housing. For fin type stops, this is easily accomplished. Hollow stops may preclude use of lever. Please contact factory for more detailed information.

Compatible Locking Devices: Any MS® pivoted bolt deadlock including“Schoolhouse” versions can be fitted with the 4550 including MS1850S, MS1950. Derivative units such as 1870 or 1870HM, flushbolts that bolt into threshold are also operable by the 4550 lever. Not compatible with MS+1890 Deadlock/Deadlatch or 2190 Interconnected Deadlock/Deadlatch or with 7/8" [22.2 mm] backset locks.

Standard Package: Individually boxed with mounting hardware and drive pins for both single point and threshold bolt-equipped locks.

Shipping weight: 3 lbs [1.36 kg]


• Available in choice of powder coat 119 to match 335 Black anodized, 121 to match 313 Dark bronze anodized, and 130 to match 628 Clear anodized
• Ordered for left or right hand door, but is easily reconfigured in the field to accommodate either door swing.


  Compatible Products – This product is compatible with the following products:

Deadlocks Flushlocks

MS1850S SeriesMS1850SN SeriesMS1950 Series Deadlocks (not compatible with 7/8” backset)

1870 Series1870HM Series Cylinder-Operated Flushbolts