Marks USA
Marks USA 5NY10A/26D Satin Chrome Left Hand Entrance Mortise Door Lock
A Grade 1 mortise lockset with steel internal components, satin chrome finish, screwless thru-bolted knobs and a three-hour fire rating for heavy-duty entrance doors
- FinishSatin Chrome
- Selling UnitBox
- TypeDeadbolts
- FeaturesSteel Body (all Internal Body Components are Steel)
- Security LevelHeavy Duty
- Location TypeInstitutional and Industrial
- Grade 1 security for heavy-duty institutional use
- Three-hour fire rating protects life safety
- All-steel internal components resist forced entry
- Screwless thru-bolted knobs prevent tampering
- ANSI-A156.13 certified and UL listed
Institutional-grade security
The Marks USA 5NY10A/26D is a Grade 1 mortise lockset built with a full steel body and internal components for institutional and industrial doors. Its entrance function combines an exterior cylinder with an interior thumb-turn, supplied with two keys and a satin chrome finish on solid brass plates.
Mortise installation requirements
The lock fits a standard mortise pocket with a 2-3/4 inch backset and a 1-1/4 by 8 inch wide front face plate. Screwless knobs are thru-bolted through the door for rigid mounting, while the scissor latch and anti-friction latch operate within the mortise cavity without exposed surface hardware.
Fire-rated capacity and limits
UL listed to ANSI-A156.13 Grade 1 with a 3 hour fire rating, the lock withstands prolonged fire exposure on rated door assemblies. The 1 inch deadbolt throw provides high-security deadlocking, though the fixed left-hand handing cannot be reversed in the field and the keyed-different cylinder does not support master-keyed systems.
Highlights
- Grade 1 security for heavy-duty institutional use
- Three-hour fire rating protects life safety
- All-steel internal components resist forced entry
- Screwless thru-bolted knobs prevent tampering
- ANSI-A156.13 certified and UL listed
Specifications
| Brand | Marks |
|---|---|
| Model | 5NY10A/26D |
| Finish | Satin Chrome |
| Selling Unit | Box |
| Type | Deadbolts |
| Features | Steel Body (all Internal Body Components are Steel) |
| Security Level | Heavy Duty |
| Location Type | Institutional and Industrial |
| Material | Steel |
| Backset | 2-3/4" |
| Grade | 1 |
| Keying | Keyed Different |
| Style | Knobs |
| Fire Rated | 3 hr |
| Series | Grade 1 New Yorker Series |
| Function | Entrance |
Questions about this item
How long does the 3-hour fire rating protect the door opening?
The lockset is UL listed with a 3-hour fire rating, meaning it maintains integrity for three hours under standard fire-test conditions.
How much heat does the steel body generate during continuous operation?
The all-steel internal components produce no measurable heat during normal use; the lock is a passive mechanical device with no electrical load.
What door thickness and handing must the opening already have for this left-hand mortise set?
The lock requires a left-hand door prepared with a 2-3/4-inch backset and a 1-1/4-inch by 8-inch mortise pocket to accept the wide front face plate.
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