Marks USA MAR175NB 175NB Communicating Passage Clutched Lever Lockset with 2-3/4in Backset, ANSI Strike, Grade 2

Marks USA 175NB Communicating Passage Clutched Lever Lockset — Lifetime Mechanical Warranty, 3.6 Million Cycles

The Marks USA 175NB is a commercial-grade cylindrical communicating passage clutched lever lockset engineered for demanding, high-traffic environments. Featuring the Survivor leverset's unique stainless steel clutch mechanism paired with bronze roller bearings on a cast retractor chassis, this lockset exceeds BHMA Grade 1 specifications by 300% — surpassing 3.6 million cycles. Designed for doors 1-5/8" to 1-7/8" thick (with optional K1904 spacer for 1-3/8" doors), it ships with a 2-3/4" backset and an ANSI #1145 ASA strike, and carries a 3-hour fire rating.

Key Features

• Exceptional Cycle Durability: Exceeds BHMA Grade 1 specifications by 300% with over 3.6 million cycles, delivering long-term reliability in high-traffic commercial applications.
• Survivor Clutch Mechanism: Unique stainless steel clutch disengages levers from the retractor when locked, allowing levers to swing freely without resistance — eliminating lever droop and dramatically reducing wear on internal components.
• Cast Retractor on Bronze Roller Bearings: Solid cast Zamac levers with 1/2" return ride on bronze roller bearings for smooth, consistent operation over millions of cycles.
• Door Thickness Compatibility: Fits doors 1-5/8" to 1-7/8" thick; use K1904 spacer for 1-3/8" doors. Supports both 2-3/8" and 2-3/4" backsets.
• Latch Specifications: Latch #1134 with 1-1/8" x 2-1/4" front, 1/2" throw, and stainless steel nose for corrosion resistance and durability.
• Thru-Bolted Roses: 3-1/4" diameter roses are spring-loaded and secured with 2 #10 thru-bolts for a solid, tamper-resistant installation.
• 3-Hour Fire Rated: Meets 3-hour fire rating requirements for use in fire-rated door assemblies in commercial construction.
• Lifetime Mechanical Warranty: Backed by Marks USA's lifetime mechanical warranty for added confidence and long-term value.

Certifications & Compliance

• Exceeds BHMA Grade 1 Specification by 300% (3.6 Million Cycles)
• ANSI/BHMA Certified
• UL Listed
• ADA Compliant
• 3-Hour Fire Rated
• Marks USA Lifetime Mechanical Warranty

Technical Specifications

• Series: 175 Series
• Latch Throw: 9/16"
• Product Group: Mechanical Locks
• Product Subgroup: Bored Locksets
• ANSI/BHMA: ANSI/BHMA, UL Listed
• Commercial/Residential: Commercial
• Function Description: Latch retracted by knobs/levers at all times
• ADA Compliant: Yes
• Keyed: No
• ANSI Function: F75
• Product Function: Passage/Hall/Closet
• Latch Type Specification: Deadlocking
• Product Category: Mechanical Locks
• Department: Door Hardware

Typical Applications

• Commercial Office Buildings
• Educational Facilities and Schools
• Healthcare Institutions and Medical Offices
• Retail Establishments
• Government and Municipal Buildings
• Multi-Tenant Residential and Hospitality Properties
• Industrial and Warehouse Facilities

Why Marks USA 175NB?

Marks USA 175 Series locksets are built around a cast retractor on bronze roller bearings chassis that exceeds BHMA Grade 1 durability standards by 300%, surpassing 3.6 million cycles. The Survivor clutch mechanism — crafted from stainless steel — sets this leverset apart by eliminating lever droop and reducing internal wear, making it an ideal choice for high-traffic commercial doors where long-term, low-maintenance performance is non-negotiable.