Sargent 4877 Classroom Mortise...
IN STOCK (leaves warehouse same day if ordered before 3pm ET)
$560.92
$318.92
Sargent 4877 Series - Classroom Mortise Deadbolt

Sargent 4877 Classroom Mortise Deadbolt with 2-3/4" Backset

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Model: 4877-26D
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In Stock (leaves warehouse same day if ordered before 3pm ET)

$560.92
$318.92
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Sargent 4877 Series Classroom Mortise Deadbolt with 2-3/4" Backset and Cylinder x Thumb Turn Operation

Professional Classroom Security Solution

The Sargent 4877 Series Classroom Mortise Deadbolt delivers maximum security and durability for high-traffic educational facilities. Featuring a laminated stacked steel deadbolt with 2-3/4" backset depth and 1" latchbolt throw, this UL Listed lock is engineered for 1-3/4" door thickness applications. The cylinder x thumb turn configuration provides controlled access with key operation from outside and thumb turn retraction from inside for enhanced classroom safety.

Professional Features & Benefits

  • Precise Door Compatibility: Designed for 1-3/4" door thickness with 2-3/4" backset depth for standard commercial door applications.
  • Heavy-Duty Construction: Laminated stacked steel deadbolt provides exceptional security and durability for demanding classroom environments.
  • Classroom Function Design: Cylinder x thumb turn operation allows key access from outside while thumb turn inside retracts but will not project deadbolt for safety compliance.
  • UL Listed Compliance: UL and ULC listed certification ensures code compliance and reliable performance in educational facilities.
  • Non-Handed Installation: Universal design accommodates both left and right-hand door configurations for installation flexibility.
  • Complete Strike System: Includes flat strike type for secure frame mounting and proper deadbolt engagement.
  • Manufacturer Warranty: 1-year limited warranty provides added confidence and protection for institutional applications.
  • Ready-to-Install Package: Includes 2 keys and all necessary components for complete installation.

Technical Specifications

  • Refer to manufacturer documentation for complete technical specifications.

Installation & Operation

  1. Review manufacturer specifications and verify door preparation requirements including 1-3/4" door thickness and 2-3/4" backset compatibility.
  2. Use manufacturer-provided templates to mark mounting hole locations accurately on door and frame surfaces.
  3. Prepare door and frame by drilling required holes and routing as specified in manufacturer instructions for mortise deadbolt installation.
  4. Install all mounting hardware and secure the deadbolt to door and frame per manufacturer torque specifications.
  5. Adjust operational components for proper alignment, latching, and smooth operation of both cylinder and thumb turn mechanisms.
  6. Test device operation to verify proper function and make final adjustments as needed. Refer to manufacturer documentation for complete installation details and troubleshooting.

Professional Applications

  • Educational Facilities and Classrooms
  • School Administrative Offices
  • Healthcare Institution Patient Areas
  • Commercial Office Buildings
  • Multi-Tenant Residential Properties
  • Government and Municipal Buildings
  • Institutional Security Applications

Why Choose Sargent Quality?

Sargent mortise deadbolt products deliver professional-grade reliability with laminated stacked steel construction and UL Listed certification for demanding institutional applications. The 1-year limited warranty and proven classroom function design ensure dependable performance in high-traffic educational environments where security and safety are essential.

Product Specs

Series:
4870 Series
Product Group:
Mechanical Locks
Product Subgroup:
Mortise Locks and Trim
Product Type:
Mortise Locks
Subcategory:
Mortise Locks and Trim
Commercial/Residential:
Commercial
Lock Function:
Classroom
Keyed Function:
Single Cylinder
Lock Type:
Deadbolt
Product Model:
4877
Product Function:
Classroom
Product Category:
Mechanical Locks
Department:
Door Hardware

Sargent 4877-26D – Frequently Asked Questions

1) How does the Sargent 4877 classroom deadbolt actually work from inside the room?
Key from the corridor side, thumb turn on the room side. The thumb turn on the 4877 retracts the deadbolt but will not project it, so nobody inside can lock the bolt out with the turn alone. Projecting the bolt takes the key. That is the classic classroom deadbolt behavior, and it is why schools use it instead of a double turn function that lets an occupant secure the door unsupervised.
2) Will the Sargent 4877 mortise deadbolt fit a 1-3/8 inch door?
No. The 4877 is built for 1-3/4 inch door thickness only, which is the standard commercial door. On a 1-3/8 inch door, common on older interior openings, the case and trim will not set up correctly and you need a lock sized for that thickness.
3) What backset and bolt throw does the Sargent 4877 deadbolt have, and will it reach my frame?
The 4877 is prepped at a 2-3/4 inch backset with a 1 inch deadbolt throw. The 2-3/4 backset is one of the two standard commercial backsets, so it drops into a door mortised for that dimension. The full 1 inch throw means it needs a frame strike pocket deep enough to take the bolt, not just a shallow latch cutout.
4) Is the Sargent 4877 a complete lockset, or do I still need a latch and lever?
It is a deadbolt only. The 4877 gives you a keyed, thumb-turn-retracted bolt with no latch and no lever trim, so it is used as auxiliary security alongside a separate latching lockset or as a secondary bolt on a door that already has passage hardware. If you want one mortise case that does both classroom keying and latching in a single prep, look at a classroom mortise lockset such as the Corbin Russwin ML2003 or the Cal-Royal NM8070, both Grade 1 classroom function for 1-3/4 inch doors.
5) Is there a keyless or electronic option instead of the key-operated Sargent 4877 classroom deadbolt?
The Sargent 4877 is mechanical, keyed from the outside with a thumb turn inside. For a code-based classroom opening, the Alarm Lock DL2700CR is a Grade 1 electronic mortise lock with classroom function for 1-5/8 to 1-7/8 inch doors, and the DL3500CR is a Grade 1 classroom-function electronic mortise lock with 300 user codes on the same door thickness range. If the requirement is specifically an electronic deadbolt, the Alarm Lock DL4500 is a Grade 1 electronic mortise deadbolt with 2,000 user codes and a privacy keypad.
6) What is a good alternative to the Sargent 4877 classroom mortise deadbolt if the opening needs a latch and lever rather than a deadbolt only?
The Sargent 4877 is a classroom mortise deadbolt with cylinder outside and thumb turn inside, so it secures the door but provides no latching or lever operation. For a classroom opening that needs a latchbolt and lever trim, the Cal-Royal NM8070 is a Grade 1 classroom mortise lockset with an auxiliary deadlatch for 1-3/4 inch doors, and the Corbin Russwin ML2003 is a Grade 1 mortise classroom lockset in the ML2000 Series, also for 1-3/4 inch doors. Either handles the latching duty the 4877 does not.
7) For a classroom door that needs intruder or lockdown capability rather than key-outside deadbolting, what should be used instead of the Sargent 4877?
The Sargent 4877 uses a classroom function where the outside cylinder controls the bolt and the inside thumb turn can only retract it, so a teacher cannot throw the bolt from inside. Where the requirement is inside lockdown, the BEST 45HCA heavy duty mortise lockbody is offered with an intruder function, and the TownSteel FME-4000 Series is a Grade 1 heavy duty electronic intruder classroom mortise lockset with RFID for 1-3/4 inch doors. The Marks USA LA318GJ is a Grade 1 classroom security indicator mortise lockset for 1-3/4 inch doors if visual status at the door is also wanted.
8) Will a Baldwin 6301 or 6310 mortise lock body work in the same door prep as the Sargent 4877?
No. The Sargent 4877 is built to a 2-3/4 inch backset, while the Baldwin 6301 entry/apartment and 6310 entry/storeroom mortise lock bodies are 2-1/2 inch backset units. The Baldwin 6301 is listed for doors 1-3/4 inch and over and the 6310 for 1-3/8 inch and over, but the backset difference alone means the case pocket and cylinder centerline will not line up with a 2-3/4 inch prep.
9) Do I have to order the Sargent 4877 handed?
No handing required. The 4877 is non-handed and works on left or right hand openings as shipped, so a facility can stock one part for every door instead of splitting inventory by swing.
10) What strike comes with the Sargent 4877 deadbolt?
Every 4877 ships with the 480 flat strike, 3-1/2 inches by 1-1/8 inches. That is the only strike option on the deadbolt, so the strike choice is already made for you; what you do need to confirm is that your frame is prepped for a flat strike of that size and has the bolt pocket behind it.
11) What is the difference between the Sargent 4877 and an electronic classroom lock like the Alarm Lock DL3500CR or TownSteel FME-2000?
The 4877 is purely mechanical: one key, one thumb turn, no batteries, no credentials to manage. The electronic classroom options work differently. Alarm Lock's DL3500CR is a Grade 1 classroom mortise lock holding 300 user codes and fits 1-5/8 to 1-7/8 inch doors, and TownSteel's FME-2000 is a Grade 1 heavy duty classroom mortise lockset using RFID credentials on 1-3/4 inch doors. Pick the 4877 when you want the lowest maintenance burden across a large door count; pick the electronic units when you need audit trails or to revoke access without rekeying.
12) Is the Kaba Ilco 185 mortise deadbolt a direct substitute for the Sargent 4877?
They serve the same role in that both are mortise deadbolt bodies and neither is handed - the Sargent 4877 is non-handed, and the Kaba Ilco 185 Series is listed as no handing with a deadbolt function. The difference is the operating side: the 4877 is a single cylinder classroom configuration with a key outside and a thumb turn inside that retracts but will not project the bolt. Confirm the 185 configuration matches the cylinder and turn arrangement your opening requires before treating it as a swap.
13) We are standardizing a school on credential-based access. What mortise classroom option replaces the Sargent 4877 key-only approach?
The Sargent 4877 operates on a key from the outside. For credentialed access on a classroom opening, the TownSteel FME-2000 Series is a Grade 1 heavy duty classroom mortise lockset with RFID for 1-3/4 inch doors, and the Schlage Electronics LEMD-GRW is a Grade 1 ENGAGE Series wireless mortise lock with a 125 kHz proximity reader and a mobile-enabled deadbolt with LED, carrying a 3 hour fire rating. The Accentra nexTouch NTM623-NR is a Grade 1 mortise lock with a capacitive touchscreen keypad and cylinder override for sites that want to keep a mechanical key path.
14) What mortise option pairs a deadbolt with privacy rather than key control, as an alternative to the Sargent 4877?
The Sargent 4877 is a single cylinder keyed classroom deadbolt, so the outside is always key controlled. Where the room needs occupant privacy instead, the Cal-Royal NM8440 is a Grade 1 privacy mortise lockset with deadbolt for 1-3/4 inch doors, and the Hager 3840S in the 3800 Series is a Grade 1 privacy mortise lock with a 2-3/4 inch backset for doors 1-3/4 to 2 inches. Both give inside control of the bolt, which the 4877 classroom function deliberately does not.
15) What mortise lock uses the same 2-3/4 inch backset as the Sargent 4877 if we want matching prep on non-classroom doors in the same building?
The Sargent 4877 is a 2-3/4 inch backset unit for 1-3/4 inch doors. The Hager 3800 Series holds that backset across several functions: the 3810S passage with rose and 3810E passage with escutcheon for doors 1-3/4 to 2-1/2 inches, the 3850E office lock with lever and escutcheon, non-keyed, also 1-3/4 to 2-1/2 inches, and the 3840S privacy for 1-3/4 to 2 inch doors. That keeps a single backset dimension across the door schedule.
16) If a corridor or entrance door does not need classroom function, what mortise lock is used instead of the Sargent 4877?
The Sargent 4877 is a classroom function deadbolt. On an entrance or corridor opening, the Cal-Royal NM8050 is a Grade 1 office/entrance mortise lockset with auxiliary deadlatch for 1-3/4 inch doors, the NM8080 is a Grade 1 storeroom mortise lockset with an interchangeable core option on the same door thickness, and the Accentra 8805FL is a Grade 1 storeroom mortise lock in the 8800 Series with the Arcadia lever. All three latch the door, which the deadbolt-only 4877 does not.
17) Can an Emtek mortise entrance lockset be used in place of the Sargent 4877?
No. The Emtek 3019 Brisbane, 3102 Memphis, 3104 Hamilton and 3106 Manhattan mortise entrance locksets are all dummy function, meaning they are trim only with no working lock mechanism. The Sargent 4877 is a keyed single cylinder classroom deadbolt with a thumb turn inside, so it is doing security work those dummy sets cannot.
18) For a healthcare or behavioral unit where the Sargent 4877 thumb turn is a concern, what mortise hardware is used instead?
The Sargent 4877 carries a projecting thumb turn on the inside face. On openings where protruding hardware is not acceptable, the TownSteel MRX-A-01 is a Grade 1 heavy duty ligature resistant arch trim mortise lockset in satin stainless for 1-3/4 inch doors, the MRX-L-01 is a Grade 1 heavy duty anti-ligature lever mortise lockset on the same door thickness, and the Marks USA 5PDN is a Grade 1 hospital passage mortise push/pull paddleset described as ligature resistant and ADA compliant in satin stainless steel.
19) We need the classroom door released from an access control panel. Is the Sargent 4877 the right choice?
The Sargent 4877 is a mechanical key and thumb turn deadbolt with no electrical connection. For remote release, the Command Access ML190 Series is a heavy-duty motorized storeroom mortise lock with field selectable EL/EU operation on 24VDC, the BEST 45HW is a heavy duty wired electromechanical mortise lock with 12V/24V operation, and the Schlage L9092EU with 03A trim is a heavy duty electric lock/unlock outside lever mortise lock, keyed outside, with request to exit on 12/24VDC for 1-3/4 inch doors.
20) What finishes does the Sargent 4877 classroom deadbolt come in?
Thirteen finishes, covering the usual institutional choices and the decorative ones: 03 bright brass, 04 satin brass, 09 bright bronze, 10 satin bronze, 10B oil rubbed dark oxidized satin bronze, 10BE and 10BL dark oxidized satin bronze, 20D dark statuary bronze lacquered, 32 bright stainless, 32D satin stainless, 26D satin chrome, plus BSP black and WSP white suede powder coat. For matching an existing school corridor, 26D and 32D are the standard pairings with most commercial lever trim.
21) Does the Sargent 4877 come with keys?
Two keys ship with the lock, along with the mounting components for the installation. For a building standardizing on one keyway across many doors, the cylinder keying is what to settle at order time; the bolt case itself is the same across all finishes.
How fast can I get the Sargent 4877-26D delivered?
Most orders ship the same day from our distribution partners, with quick delivery throughout the continental U.S. Need it urgently? Contact Us for expedited shipping options.
Can I return it if it doesn’t work for me?
Yes—ZenSupply offers a hassle-free return policy. If the product isn’t the right fit, reach out to our support team for a return authorization or setup a return by following our return instructions.
Does the Sargent 4877-26D come with a warranty?
Absolutely. The Sargent 4877-26D is backed by a manufacturer’s warranty. For full warranty terms, check the product documentation or Contact Us.
How do I get technical support or installation help for the Sargent 4877-26D?
You can call, text, or email our expert support team for fast answers. We’re here to help with product selection, installation tips, and troubleshooting. Contact Us
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