About this item
The Cal Royal NM8456 is the corridor function model in Cal-Royal's NM Series heavy duty Grade 1 mortise lockset line. It's an extra heavy duty commercial mortise lock that meets ANSI/BHMA A156.13-2017 Series 1000 operational and security Grade 1 standards, holds a UL 3-hour fire rating, and carries a BHMA certified lifetime warranty. American Locksets stock the NM8456. Free shipping on orders over $300 and same-day shipping available.
How the Corridor Function Works (ANSI F13)
Corridor function is one of the most commonly specified functions on commercial building hardware schedules, and also one of the most misunderstood. Here's exactly what the NM8456 does:
The latch bolt retracts from either side via the lever handle, just like a passage lock, as long as the outside lever hasn't been locked. The outside lever is controlled by a rocker-type stop-works toggle button on the inside of the lock case - one press locks the outside lever rigid, a second press releases it. When the outside lever is locked, the key from outside retracts the latch for authorized entry. The inside lever always retracts the latch regardless of the outside lock state, so egress is never blocked.
The deadbolt operates separately from the latch. It's thrown and retracted by key from the outside or by thumbturn from the inside. When you turn the inside lever, it retracts both the latch bolt and the deadbolt simultaneously - one motion clears the door completely for exit.
That combination is what makes the corridor function right for main corridor doors in schools, offices, hospitals, and commercial buildings where the door needs to be freely accessible during business hours and secured after hours or on demand from inside.
Cal Royal NM Series Mortise Lock: What Makes It Heavy Duty Grade 1
The NM Series is Cal-Royal's extra heavy duty mortise platform. Every component in the NM8456 is built to the Grade 1 standard, which is the highest commercial rating for mortise locks under ANSI A156.13.
The lock case is heavy gauge zinc chromate steel. The front plate is heavy gauge steel, 8 inches by 1-1/4 inches by 3/32 inches, accommodating flat doors and doors beveled 1/8 inch in 2 inches. The armored front is wrought brass attached by machine screws directly to the lock case front, surrounding the latch and deadbolt. That surrounding armored front is what gives the mortise lock its resistance to lateral attack - there's no exposed mechanism at the door edge, just brass over steel.
The deadbolt is 1-inch throw, brass chrome-plated with hardened steel rollers. The hardened steel inserts in the bolt are what prevent sawing through the bolt during a forced entry attempt. The guard bolt is extruded brass, chrome plated. The stop works is a rocker type, brass, chrome plated.
Specifications
Model: Cal Royal NM8456
Series: NM Series Heavy Duty Grade 1 Mortise Lockset
Function: Corridor / Exit, ANSI Function F13
Door Thickness: 1-3/4" standard
Backset: 2-3/4"
Lockcase: Heavy gauge zinc chromate steel
Front Plate: Heavy gauge steel, 8" x 1-1/4" x 3/32". Fits flat doors and doors beveled 1/8" in 2"
Armored Front: Wrought brass, machine screw attached to lock case front
Deadbolt: 1" throw, brass chrome-plated with hardened steel rollers
Guard Bolt: Extruded brass, chrome plated
Stop Works: Rocker type, brass, chrome plated
Strike: Brass, non-handed curved strike 4-7/8" x 1/4". "F" mark stamped on strike for fire door identification
Handing: Handed. Easily field-reversible.
Certifications: ANSI/BHMA A156.13-2017 Series 1000, Operational and Security Grade 1 Extra Heavy Duty. UL Listed "A" Label, 3-hour fire rating for single or pairs of fire doors.
Warranty: BHMA Certified Lifetime Warranty
Trim Options
The NM8456 is available with multiple sectional lever trim configurations. The SE and SS trim designations indicate escutcheon and sectional lever trim styles respectively. GS, JS, KS, and TS trim options provide different lever and escutcheon profiles for various architectural requirements. Trim is specified separately from the lock case - confirm your trim style and finish when ordering.
Available finishes include US26D (satin chrome), US32D (satin stainless), US10B (oil rubbed bronze), US3 (bright brass), US26 (bright chrome), and US4 (satin brass). Not all finishes are stocked - contact American Locksets at 877-471-4870 to confirm in-stock finish availability before ordering.
Interchangeable Core Options
The NM8456 accepts small format interchangeable cores (SFIC) from Best, Falcon, and Arrow for facilities already standardized on those key systems. Large format interchangeable core (LFIC) for Schlage is also available. IC core compatibility means re-keying any NM8456 in the building is a field operation - no locksmith required, no cylinder removal. The control key pulls the core and a new pre-keyed core drops in.
The NM Series Function Range
If the NM8456 corridor function isn't the right spec for your opening, the full NM Series covers every standard commercial mortise function. The NM8050 handles office/entrance (F04). The NM8070 is a classroom (F05). The NM8080 covers the storeroom (F07). The NM8453 has an entrance with deadbolt (F20). The NM8465 covers the closet/storeroom with a deadbolt. The NM8473 handles dormitory/bedroom (F21). Every model in the series shares the same case construction and trim compatibility, so a building standardized on NM Series hardware carries consistent look and feel throughout.
American Locksets has stocked Cal-Royal NM Series mortise locks since 2001.
Trusted Since 2001
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