UL Listed Fire Rated American Mortise Lock for Entrance Interior Door-DDAL04

Latch bolt operated by lever from elther salde except when outside lever is made inoperative by a slop or mechanical means other than kay. When oultside lever is locked, latch bolt retracled by key lfrom oulside or byoperating inside lever.Auxiliary dead latch.

Model:
DDAL04
Brand:
D&D Hardware
Certification:
UL 10C fire rated 3 hours
Material:
Stainless Steel
Color:
Silver
Application:
Wooden Door, Metal Door

Finish:	SSS Black Gold
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Quantity:



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Door Lock for Entrance Door Entrance Interior Door Lock

how this UL Listed mortise lock function applies to entrance interior doors?

Application for Entrance Interior Doors

1. Private Office Entrances
In commercial office settings, this lock function is commonly specified for individual office doors that require privacy and security when the occupant is away. The outside lever can be locked by a stop (often a push-button or toggle on the interior face), preventing entry from the corridor. When locked, employees can re-enter using a key from the outside, while the inside lever always remains free for immediate egress. The UL Listing ensures the lock meets fire safety standards if the office door is part of a fire-rated corridor wall .

2. Apartment or Multi-Family Unit Entry Doors
This function is widely used on apartment entrance doors. Residents can lock the outside lever using an interior stop when they are home for privacy, or lock it when they leave, requiring a key to re-enter. The auxiliary dead latch provides additional security by preventing the latch from being "shimmed" or forced open with a credit card. The UL 180-minute fire rating commonly found on such locks ensures compliance with building codes for residential unit entry doors that open onto common corridors.

3. Inner Entry Vestibules or Suite Entrances
For doors leading from a building lobby into a private suite or executive office cluster, this lock function offers controlled access. Authorized personnel can use a key to enter from the public side, while occupants inside can exit freely at any time by simply operating the lever. The stop feature allows occupants to temporarily prevent entry from the outside without needing to use a key. The Grade 1 BHMA construction ensures durability in high-traffic interior applications.

4. Compliance with Emergency Egress Requirements
A critical feature of UL Listed mortise locks with this function is that they are designed to be panic proof or have emergency egress function . This means that even when the outside lever is locked, simply turning the inside lever instantly retracts the latch bolt, allowing occupants to exit without any additional steps. This meets life safety codes (NFPA 101) for all interior entrance doors.

5. Fire Rating Integrity
When installed on a fire-rated interior door (such as an office or apartment door separating a corridor from an occupied space), the UL Listing (e.g., UL 10C with 3-hour or 180-minute rating) confirms that the lock will maintain the door's integrity during a fire, preventing the spread of flames and smoke.