MS® Series Mechanical Deadlock | 13/16" Vertical Bolt Throw | Ultra-Narrow Stile & Aluminum Glass Door Applications | Mortise Cylinder Operated

Secure commercial aluminum and compatible hollow metal doors with the Adams Rite MS1861-01 Bottom Rail Deadlock, a heavy-duty mechanical locking solution designed for doors with limited vertical space for conventional mortise deadlocks.

The MS1861-01 installs horizontally inside the bottom rail of a compatible commercial door, providing one-point vertical locking directly into the threshold.

Its stainless steel cylindrical bolt measures 3/8 inch in diameter and extends 13/16 inch into the threshold to provide a positive mechanical locking connection.

The compact, corrosion-resistant steel lock case measures 1" × 6" × 1-13/16", making it suitable for ultra-narrow stile and certain aluminum-framed glass door applications.

The lock operates using a compatible 1-inch mortise cylinder with an Adams Rite MS® cam or an appropriately selected thumbturn.

A full 360-degree turn of the key or thumbturn projects or retracts the deadbolt. When used with a keyed cylinder, the key can be removed only when the bolt is fully locked or unlocked.

Designed for commercial storefronts and other properly prepared door openings, the Adams Rite MS1861-01 delivers dependable mechanical security in a compact bottom-rail configuration.

Key Features

• One-Point Vertical Locking: Projects a single deadbolt downward into the threshold.

• Bottom Rail Installation: Fits horizontally inside compatible commercial door bottom rails.

• Ultra-Narrow Stile Applications: Designed for doors with insufficient space for traditional vertically mounted locks.

• 3/8" Stainless Steel Bolt: Durable cylindrical threshold bolt.

• 13/16" Bolt Throw: Provides positive engagement with a properly prepared threshold.

• 2-1/4" Minimum Backset: Approximate minimum cylinder backset for the MS1861-01 configuration.

• Compact Lock Case: Measures 1" × 6" × 1-13/16".

• Corrosion-Resistant Finish: Zinc-plated steel lock case.

• 360° Key Operation: Mechanically projects or retracts the bolt.

• Positive Key Retention: Key removal is possible only in the fully locked or unlocked position.

• Mortise Cylinder Compatible: Accepts compatible 1" mortise cylinders with MS® cam.

• Thumbturn Compatible: Can be operated with an appropriate thumbturn.

• Flexible Cylinder Configuration: Accommodates compatible cylinder operation from either or both sides.

• Simplified Threshold Preparation: Uses a drilled threshold opening instead of a projecting floor strike.

• Commercial Door Security: Suitable for properly prepared aluminum and hollow metal door applications.

• Upgradeable Design: Compatible with the separately available Adams Rite 4014 conversion kit for two-point operation, subject to door preparation.

Product Specifications

• Manufacturer: Adams Rite

• Parent Company: ASSA ABLOY

• Model / SKU: MS1861-01

• Series: MS1861 MS® Bottom Rail Deadbolt

• Product Type: Mechanical Bottom Rail Deadlock

• Locking Configuration: One-Point Vertical Bolt

• Installation Position: Horizontal, Inside Door Bottom Rail

• Minimum Cylinder Backset: Approximately 2-1/4" (57.2 mm)

• Cylinder Center Height: 1-7/8" (47.6 mm) Above Bottom Edge of Door

• Lock Case Width: 1"

• Lock Case Length: 6"

• Lock Case Depth: 1-13/16"

• Case Material: Steel

• Case Finish: 603 Zinc-Plated Steel

• Bolt Material: Stainless Steel

• Bolt Diameter: 3/8"

• Vertical Bolt Throw: 13/16"

• Threshold Hole Diameter: 7/16" for Specified Metal Installations

• Cylinder Type: Mortise Cylinder with MS® Cam

• Typical Cylinder Length: 1"

• Cylinder Diameter: 1-5/32"

• Operating Rotation: 360°

• Operation: Mechanical Key or Thumbturn

• Compatible Door Types: Properly Prepared Aluminum or Hollow Metal Doors

• Electrified Operation: Not Available

• Fire Rating: Not Fire Rated

• Standard Packaging: Individually Boxed

• Mounting Screws: Included

• Mortise Cylinder: Sold Separately

• Thumbturn: Sold Separately

• Tube Spacers: Available Separately

• Manufacturer Shipping Weight: 1-3/4 lb

How the MS1861-01 Works

1. Bottom Rail Installation

The deadlock mounts horizontally within the lower rail of a compatible commercial door.

Its compact mechanical case is particularly useful where there is insufficient vertical space for a conventional mortise deadlock.

2. Vertical Bolt Operation

When the compatible key or thumbturn is rotated through 360 degrees, the vertical stainless steel bolt extends downward into a properly drilled threshold opening.

The bolt provides a single mechanical locking point at the bottom of the door.

3. Positive Locking

The MS® locking mechanism maintains the bolt in its fully projected or fully retracted position.

When a keyed cylinder is installed, the key can only be removed when the lock reaches one of these two positions.

4. Unlocking

Turning the key or thumbturn in the appropriate direction retracts the bolt from the threshold.

Once the bolt is retracted, the door can be opened, provided any additional door hardware is also released.

Compatible Cylinders & Accessories

Adams Rite 4036 Mortise Cylinder

Compatible mortise cylinder with MS® cam for key-operated locking applications.

Sold separately.

Adams Rite 4066 Thumbturn

Compatible thumbturn for applications requiring thumbturn operation.

Sold separately.

Adams Rite 4014 Conversion Kit

Allows a compatible MS1861-01 mechanism to be configured for vertical and horizontal two-point locking.

Important: Converting to two-point operation requires verifying the correct MS1861-02 cylinder location, door preparation, and associated hardware.

Tube Spacers

Available separately where required by the door's bottom-rail construction.

The correct spacer length and quantity depend on the installation.

Recommended Applications

• Commercial Aluminum Storefront Doors

• Ultra-Narrow Stile Doors

• Aluminum-Framed Glass Doors

• Compatible Tempered Glass Door Bottom Rails

• Commercial Hollow Metal Doors

• Retail Storefront Entrances

• Commercial Office Entrances

• Institutional Door Hardware

• Commercial Door Lock Replacement

• Bottom Rail Locking Systems

• Mechanical Security Retrofits

• Commercial Door Hardware Installations

Installation & Compatibility

The Adams Rite MS1861-01 is intended for professional installation in properly prepared commercial door bottom rails.

Installation Requirements

• Verify that the door construction supports bottom-rail deadlock mounting.

• Confirm sufficient space for the 1" × 6" × 1-13/16" lock case.

• Provide the correct mortise cylinder preparation.

• Position the cylinder centerline at the required height above the bottom edge.

• Verify the minimum 2-1/4" backset.

• Prepare the correct 7/16" threshold hole for the vertical bolt in applicable metal installations.

• Use an appropriate cylinder with the required MS® cam.

• Install tube spacers where required by the bottom-rail construction.

• Test full bolt projection and retraction.

• Verify that the door closes and opens without interference.

Important Product Information

• The MS1861-01 is a one-point vertical-bolt deadlock.

• The horizontal bolt is not included.

• The lock is not fire rated.

• It is not recommended for wood doors.

• This product has no manufacturer-provided electrified option.

• The standard package includes mounting screws.

• Mortise cylinder, keys, and thumbturn are not included.

• Required tube spacers are sold separately.

• Adams Rite does not supply a separate strike plate for this model; the specified installation uses a drilled threshold opening.

• Verify that the locking arrangement is permitted for the opening's required egress function.

• Do not install a key-operated deadlock in a manner that violates applicable emergency-egress or fire codes.

• Follow the Adams Rite installation instructions and local Authority Having Jurisdiction requirements.

Why Choose the Adams Rite MS1861-01?

The Adams Rite MS1861-01 Bottom Rail Deadlock delivers dependable one-point mechanical security for commercial doors with limited space for traditional locking hardware.

Its compact zinc-plated steel case, 3/8-inch stainless steel vertical bolt, 13/16-inch throw, and MS® mortise-cylinder operation make it a practical solution for properly prepared ultra-narrow stile and aluminum-framed glass doors.

For commercial door repairs, new storefront installations, and bottom-rail lock replacements, the MS1861-01 provides a proven mechanical locking solution from Adams Rite.