8' Keyed Removable Mullion | Steel Construction | For Compatible Rim Exit Devices | USP Finish

Provide a secure center-latching point for paired commercial doors with the Liberty Exit Devices 60 Series Keyed Removable Steel Mullion.

Designed for compatible double-door openings using rim exit devices, this heavy-duty 8-foot steel mullion installs between the doors to provide a solid strike-mounting surface for the exit hardware.

The keyed removable design allows authorized personnel to remove the mullion when the full width of the opening is needed for deliveries, equipment movement, oversized traffic, or facility access.

Finished in USP – Unfinished Steel, this mullion is a practical solution for demanding commercial, institutional, and industrial openings.

Key Features

• Liberty Exit Devices 60 Series

• 8' keyed removable steel mullion

• Designed for compatible paired-door applications

• Intended for use with compatible rim exit devices

• Provides a center strike-mounting point between paired doors

• Keyed-removable configuration

• Allows authorized removal of the mullion

• Restores the full clear width of the opening when removed

• Heavy-duty steel construction

• Commercial-grade door hardware

• Ideal for high-traffic commercial openings

• Suitable for new installations, replacements, and retrofit applications

• USP – Unfinished Steel

Keyed Removable Design

Unlike a fixed mullion, the keyed removable configuration allows the mullion to be released and removed from the opening by authorized personnel.

This provides the benefits of a center mullion during normal operation while still allowing the full double-door opening to be used when necessary.

Common situations include:

• Equipment deliveries

• Pallet movement

• Large carts

• Furniture relocation

• Maintenance equipment

• Emergency facility access

• Oversized materials

Once the opening needs to return to normal service, the mullion can be reinstalled to restore the center latching point.

Designed for Paired Rim Exit Devices

A removable mullion converts a paired-door opening into two individual latching points for compatible rim exit devices.

Each door can latch against a strike mounted to the center mullion.

A typical configuration includes:

Left Door

• Rim exit device

• Strike mounted to mullion

Right Door

• Rim exit device

• Strike mounted to mullion

Center

• Liberty 60 Series keyed removable mullion

This setup provides dependable independent latching while retaining the ability to remove the center post when the entire opening width is required.

8-Foot Mullion

The mullion is supplied in an 8-foot nominal length for compatible commercial door openings.

Before ordering, verify:

• Opening height

• Frame dimensions

• Existing mullion preparation

• Door clearances

• Required mounting conditions

Field modification should only be performed where permitted by the product installation requirements.

USP – Unfinished Steel

This model is supplied in:

USP – Unfinished Steel

The unfinished steel surface is suitable for installations where the mullion will be field finished, painted, or otherwise coordinated with the surrounding opening.

Proper surface preparation should be performed before applying a final field coating.

Product Specifications

Brand: Liberty Exit Devices
Series: 60 Series
SKU: 60M-8-USP
Product Type: Keyed Removable Mullion
Material: Steel
Length: 8'
Finish: USP – Unfinished Steel
Application: Paired Commercial Doors
Exit Device Type: Compatible Rim Exit Devices
Function: Removable Center Strike Support
Removal: Key Controlled
Use: Replacement / Retrofit / New Installation

Keyed Mullion vs. Fixed Mullion

Keyed Removable Mullion

• Can be removed by authorized personnel

• Provides full opening width when removed

• Excellent for facilities requiring occasional oversized access

• Maintains normal rim-device latching when installed

Fixed Mullion

• Permanently mounted in the opening

• Provides a continuous center strike support

• Does not provide convenient full-width opening access

For commercial facilities requiring flexibility, a keyed removable mullion can offer a significant operational advantage.

Mullion vs. Double-Door Strike

A keyed removable mullion provides a center post between the doors so compatible rim devices can latch independently.

A double-door strike instead mounts to the inactive leaf, allowing a rim exit device on the active leaf to latch directly against the other door.

The correct configuration depends on:

• Door operation

• Required clear opening

• Exit-device arrangement

• Fire rating

• Facility requirements

• Applicable codes

Common Applications

Ideal for:

• Paired hollow metal doors

• Double commercial doors

• Rim exit-device openings

• Schools and universities

• Hospitals

• Healthcare facilities

• Government buildings

• Warehouses

• Distribution centers

• Manufacturing facilities

• Retail facilities

• Office buildings

• Institutional buildings

• High-traffic commercial entrances

Replacement Applications

Use the Liberty 60 Series removable mullion when the existing mullion is:

• Bent

• Damaged

• Corroded

• Missing

• Difficult to remove

• No longer properly supporting the strikes

• Being upgraded from fixed to keyed removable

• Being installed as part of a new rim-device system

Before replacement, inspect the frame mounting points and existing exit-device strikes.

Ordering Information

Before ordering, verify:

• 8' mullion height requirement

• Liberty 60 Series compatibility

• Paired-door configuration

• Rim exit-device application

• Door and frame dimensions

• Strike configuration

• Header mounting conditions

• Floor mounting conditions

• Required clear opening

• Fire-rating requirements

Fire Door Note

Do not assume a standard removable mullion is approved for every fire-rated opening.

For a labeled fire-door assembly, verify that:

• The mullion is specifically listed for the fire-rated application

• The exit devices are approved fire exit hardware

• The strikes are compatible with the listed system

• The door and frame retain the required labeling

• Removal and reinstallation procedures comply with the applicable listing

The complete opening must comply with applicable fire and life-safety requirements.

What's Included

(1) Liberty Exit Devices 60 Series 8' Keyed Removable Steel Mullion – USP

Not Included Unless Specifically Stated

• Rim exit devices

• Exit-device strikes

• Outside trim

• Cylinders

• Door closers

• Door

• Frame

• Access-control hardware