Secure narrow-stile commercial doors with the Adams Rite MS1861-01-603-IB MS® Bottom Rail Deadbolt, a heavy-duty one-point locking solution designed for doors where conventional vertical lock installation space is limited.

The MS1861 installs horizontally inside the bottom rail of the door and projects a hardened vertical bolt downward into the threshold. This configuration is particularly useful for ultra-narrow stile aluminum doors, hollow metal doors, and compatible tempered-glass door applications.

The MS1861-01 configuration features vertical bolt operation only, providing a single secure locking point into the threshold.

Key Features

• Genuine Adams Rite MS® Series

• Part Number: MS1861-01-603-IB

• MS® Bottom Rail Deadbolt

• One-point locking

• Vertical bolt only

• Installs horizontally in the bottom rail

• Ideal for ultra-narrow stile applications

• Stainless-steel vertical threshold bolt

• 3/8" diameter bolt

• 13/16" bolt throw

• Key or thumbturn operated

• 360° cylinder rotation projects or retracts the bolt

• Key removable only when fully locked or unlocked

• Accepts standard Adams Rite-compatible mortise cylinder with MS® cam

• 603 Zinc-Plated Steel

• Individually boxed

• Non-handed bottom-rail application

• Commercial-grade security hardware

Vertical Bolt Only – MS1861-01

The -01 configuration is a single-point deadlock.

When operated, the vertical bolt projects downward from the bottom rail of the door and engages a properly prepared hole in the threshold.

Unlike the MS1861-02, this version does not include a horizontal bolt into the jamb or opposing door.

MS1861-01

Vertical threshold bolt only

MS1861-02

Vertical threshold bolt plus horizontal bolt

This listing is specifically for the MS1861-01 vertical-bolt-only model.

Bottom Rail Installation

The MS1861 is designed to lie horizontally inside the bottom rail, making it especially useful when the door does not provide enough vertical stile space for a conventional MS® deadlock.

Typical applications include:

• Ultra-narrow stile aluminum doors

• Commercial glass entrances

• Tempered-glass doors with compatible bottom rails

• Hollow metal doors

• Storefront entrances

• Commercial security doors

Adams Rite does not recommend the MS1861 for wood doors.

Vertical Threshold Bolt

The MS1861-01 uses a stainless-steel vertical bolt measuring:

Diameter: 3/8"
Throw: 13/16"

For metal threshold applications, a properly located 7/16" drilled hole provides the strike point for the vertical bolt.

A separate conventional strike plate is not normally used for the standard metal threshold application.

Cylinder Backset

The MS1861-01 requires a minimum cylinder backset of approximately 2-1/4".

The cylinder centerline is positioned approximately 1-7/8" above the bottom edge of the door.

Always verify the existing door preparation before ordering or machining the opening.

Cylinder Requirements

The MS1861 accepts a standard:

• 1" length mortise cylinder

• 1-5/32" diameter

• Adams Rite MS® cam

Compatible Adams Rite mortise cylinders and thumbturns are available separately.

The lock can accept a cylinder from either or both sides, depending on the required door configuration.

Lock Case

Case Size: Approximately 1" × 6" × 1-13/16"

The steel lock case features corrosion-resistant plating for dependable commercial service.

Depending on the internal construction of the bottom rail, tube spacers may be required and should be ordered separately when necessary.

Packaging Details

The IB suffix means:

Individually Boxed

Standard factory packaging includes:

• 1 Adams Rite MS1861-01 Bottom Rail Deadbolt

• Mounting screws

Sold Separately

• Mortise cylinder

• Thumbturn

• Tube spacers

• 4014 conversion kit

• Other related hardware

Approximate manufacturer-listed shipping weight for the MS1861-01 is 1-3/4 lbs.

Product Specifications

Brand: Adams Rite
Series: MS®
Model: MS1861-01-603-IB
Product Type: Bottom Rail Deadbolt / Deadlock
Locking Points: One
Bolt Operation: Vertical Only
Vertical Bolt Diameter: 3/8"
Vertical Bolt Throw: 13/16"
Minimum Cylinder Backset: Approximately 2-1/4"
Cylinder Centerline: 1-7/8" Above Bottom of Door
Case: 1" × 6" × 1-13/16"
Finish: 603 Zinc-Plated Steel
Cylinder: Standard 1" Mortise Cylinder with MS® Cam
Cylinder Included: No
Packaging: IB – Individually Boxed
Fire Rated: No
Application: Bottom Rail Commercial Door Security

Ideal Applications

• Aluminum storefront doors

• Ultra-narrow stile doors

• Tempered-glass entrances

• Hollow metal doors

• Retail storefronts

• Commercial buildings

• Office entrances

• Shopping centers

• Institutional facilities

• High-security commercial openings

Important Ordering Information

Before ordering, verify:

• MS1861-01 vertical-bolt-only configuration

• Bottom-rail dimensions

• Minimum cylinder backset

• Cylinder and MS® cam requirements

• Threshold preparation

• Need for tube spacers

• Existing door construction

The MS1861 is not fire rated and is not recommended for wood doors.