MS1850SN Series MS® Deadlocks

The ANSI size MS1850SN Series MS® Deadlock utilizes a laminated stainless steel bolt and the ANSI size MS1850SN-45X Series MS Deadlock utilizes a stainless steel hookbolt, both activated by a pivot mechanism to provide maximum security for hollow metal or wood doors.


For hollow metal or wood doors prepared for hardware according to the specifications of the American National Standards Institute (ANSI), the MS1850SN410 Series MS® Deadlock provides maximum security and ease of installation. Its standard 1-1/2” [38.1 mm] backset dimension provides adequate clearance for the deep stop on the door jamb of hollow metal entrances.

The ANSI size MS1850SN450 Series MS® Deadlock provides maximum security and ease of installation for hollow metal or wood sliding doors. Its standard 1-1/2” [38.1 mm] backset dimension provides adequate clearance for the deep jamb “pocket” of many commercial and industrial entrances. The locking mechanism is identical to the widely used MS1850S Series MS® Deadlock, except that the massive laminated bolt is provided in a hook shape to resist the parting motion of sliding door and jamb. The over-center maximum security (MS) locking action assures that forced entry attempts to pry the door in any direction, up, down, or sideways will be defeated. Also useful for swinging doors closing against jambs too shallow for the 1-3/8” [34.9 mm] throw of the MS1850SN410 Series MS® Deadlock.



360° turn of key or thumbturn projects or retracts the counterbalanced bolt. Key can be removed only when bolt is in a positively locked or unlocked position. Lock accepts any standard 1" [25.4 mm] length, 1-5/32" [29.4 mm] diameter mortise cylinder with MS® cam such as the 4036 Mortise Cylinder, available separately or thumbturn such as the 4066 Thumbturn, available separately. Lock accepts cylinder from either or both sides.



Backset: 1-1/2” [38.1 mm] available only

Case: Measures 1” x 6” x 2-1/4” [25.4 mmx 152.4 mm x 57.2 mm]. Steel with corrosion-resistant plating.

Bolt: Eight-ply laminated stainless steel. Center ply has alumina-ceramic core to defeat any hacksaw attack, including rod-type “super” hacksaws.
MS1850SN410: Standard straight bolt measures 5/8" x 1-3/8" x 2-7/8" [15.9 mm x 34.9 mm x 73.0 mm] with 1-3/8" [34.9 mm] throw.
MS1850SN450: Hookbolt measures 5/8" x 1-3/8" [15.9 mm x 34.9 mm] with13/16" [20.6 mm] throw. Hook shape repels pry bar attempts to “spread” the door from its jamb or lift it off its track.

Faceplate: Measures 1-1/4” x 8” [31.8 mm x 203.2 mm].

Strike: See catalog page for dimensions of strike slot which can be cut in metal jamb. Lipped, ANSI-spec, and other strike plates available separately.

Standard Package: Individually boxed with faceplate and mounting screws. Strike plates, cylinders and/or thumbturns available separately.

Shipping Weight: 1-1/2 lbs [0.68 kg].



• “SCHOOLHOUSE” version, also available,is modified so that operation from inside is “unlock only”. Specify SCH1850SN410 or SCH1850SN450 Series. Same faceplate and backset options as MS1850SN or MS1850SN-450 Series.


Related Products: When purchasing this product, please consider the following related products, available separately:

Accessories Cylinders Trim Special Order Options

4000, 4001, MS4002 Deadlock Strikes4015 Threshold Bolt4016 Header Bolt for multi-point locking, 4085 Header Bolt for pairs of doors.  

4089 Exit Indicator

Lock mounting accessories and options

Standard 1" length, 1-5/32” diameter mortise cylinder with MS® cam such as 4036 Mortise Cylinder, 4066ThumbturnMS4043 Cylinder Guard

3090-150 e-force Series Keyless Entry, 4550 Deadlock Lever

Schoolhouse function available as special order.