Product Description
12-L980-GRAY-86 — Sargent Lockable Fire-Rated Steel Mullion, 86" (7 ft 2 in), Gray Prime Coat
Some fire-rated pair-door openings can't have an unkeyed removable mullion sitting there — insurance, code, or building security want the mullion locked in place and only a key can release it. The Sargent 12-L980 is the answer: same 2" x 3" steel profile and UL 3-hour fire label as the 12-980, but with a lock cylinder housing built into the body. Engineered specifically for the Sargent 12-8800 rim exit device family — same manufacturer, same UL fire label, same retainer pattern. Authorized key unlocks, mullion comes out, opening clears.
Where This Mullion Fits
This is core Commercial Door Hardware — the kind of Double Door Hardware spec'd into schools, hospitals, office buildings, and any code-required egress. Any Pair Door Opening with panic exit devices needs a center post for the rim latches to catch, and that's exactly what this mullion is: the Panic Bar Strike Post between the two door leaves. When the building inspector signs off on Life Safety Code Compliance (NFPA 80 / NFPA 101) on a fire-rated pair opening, this UL-labeled mullion is the part that lets the assembly hold its 3-hour rating with the doors closed under fire conditions.
- UL Listed 3-Hour Fire Rating — meets code on every fire-rated pair-door opening
- 2" x 3" Steel Construction — ANSI Grade 1, channel iron top and bottom retainers included
- Built-in Lock Cylinder Housing — 1-1/8" mortise cylinder (sold separately) anchors the mullion in place
- Made in USA — manufactured by Sargent (ASSA ABLOY) in New Haven, CT
This is the 86" (7 ft 2 in) lockable version — Standard 7-ft doors (up to 7'2"). Lock cylinder housing is sized for a 1-1/8" mortise cylinder (Sargent #41 standard, #42 and #43 also fit). The cylinder is NOT included — spec the Sargent (or other Sargent-compatible) mortise cylinder separately, keyed to your building's master system.
Cylinder required, sold separately. The 12-L980 takes a standard 1-1/8" mortise cylinder. The Sargent #41 is the stock cylinder; #42 and #43 also fit. Specify keyway and keying to match the rest of the building's master key system.
SKU Breakdown
| Segment | Code | What It Means |
|---|---|---|
| Fire Rating | 12- | UL Listed 3-hour fire rated (the 12- prefix is Sargent's fire-rated code) |
| Lock Function | L | Lockable — cylinder housing built in; key releases the mullion |
| Series | 980 | Steel mullion for 12-8800 rim exit devices |
| Finish | GRAY | Gray prime coat (paintable steel finish) |
| Height | 86 | 86" (7 ft 2 in) mullion height |
Technical Specifications
| Specification | Value |
|---|---|
| SKU | 12-L980-GRAY-86 |
| Brand | Sargent (ASSA ABLOY) |
| Series | 80 Series Steel Mullion |
| Product Type | Fire-Rated Mullion (vertical center post for pair-door openings) |
| Function | Lockable — key cylinder releases the mullion |
| Material | Steel |
| Cross-Section | 2" x 3" rectangular |
| Height | 86" (7 ft 2 in) |
| Fits Door Height | Standard 7-ft doors (up to 7'2") |
| Finish | Gray Prime Coat (paintable) |
| Finish Code | GRAY |
| Fire Rating | UL Listed, 3-hour fire rating |
| ANSI/BHMA Grade | Grade 1 |
| Retainers | Channel iron top and bottom; malleable iron retainer hardware (included) |
| Compatible Exit Device | Sargent 12-8800 series rim exit devices (fire-rated companion) |
| Cylinder Required | Yes — 1-1/8" mortise cylinder, NOT INCLUDED (sold separately) |
| Country of Origin | United States (New Haven, CT) |
| Warranty | Sargent limited warranty |
Compliance & Codes
UL Listed, 3-hour fire rating. ANSI/BHMA Grade 1. Suitable for pair-door openings on fire-rated assemblies when paired with a Sargent 12-8800 series rim exit device. Confirm local AHJ requirements for cross-corridor, stair, and exit enclosure applications.
What's in the Box
- One Sargent 12-L980 Steel Mullion — gray prime coat, 2" x 3" rectangular profile, with built-in lock cylinder housing
- Top Channel Iron Retainer — mounts to the head frame, locks the mullion in position at the top
- Bottom Channel Iron Retainer — mounts to the threshold/sill, anchors the mullion at the bottom
- Mounting Fasteners — malleable iron retainer hardware and 1/4-20 mounting screws (everything needed to install)
Cylinder NOT included — order a 1-1/8" Sargent mortise cylinder (#41 standard) separately.
Pro-Installer FAQ
Q: Does this include the rim strikes?
A: No. The rim strikes ship with the exit device (Sargent 12-8800 series). This mullion includes the channel iron mounting retainers and all the hardware needed to install it center-post between your doors — the strikes themselves come in the 12-8800 box.
Q: Will this work with a non-Sargent rim exit device?
A: The 12-980 / 12-L980 is engineered for the Sargent 12-8800 fire-rated rim family. Other manufacturers' rim exit devices may not align with the channel iron retainer pattern, and crossing brands on a fire-rated assembly can break the UL label. Stick with the 12-8800 series unless you have written confirmation from the AHJ.
Q: Can I cut this down in the field?
A: On non-fire-rated installs the 980S (non-fire) version can be field-cut. The fire-rated 12-980 / 12-L980 ships at fixed lengths and the UL label is height-specific — cutting voids the fire label. Pick the closest stock height (86" for standard 7-ft doors, 120" for 10-ft doors) and order to the opening.
Q: Lockable vs removable — which one do I need?
A: Lockable (12-L980) is the right call when code or insurance requires the mullion stay anchored in place and only an authorized key can release it. Removable (12-980) is for openings where the mullion comes out freely for big-opening events (loading, moving equipment) and you don't need it locked in any particular position. Same UL 3-hour fire label on both.
Warranty
Sargent provides a limited warranty against defects in materials and workmanship under normal use and service, when installed per Sargent specifications. Lock Depot sells brand-new Sargent products with the full manufacturer warranty in effect.
Looking for other mullion options? Browse the full commercial door mullion category for Sargent and Detex variants in fire-rated and non-fire-rated configurations.
Lock Depot sells brand new Sargent products with the full manufacturer warranty. Questions about fit, cylinder spec, or fire-rated pair-door assemblies? Call us — we've installed these on real openings.
Product images are representative and may not depict the exact SKU, finish, or configuration listed. Always verify specifications before ordering.
