Marks USA MAR5SS55N 5SS55N Institutional Anti-Ligature Passage Mortise Lockset with Solid Stainless Steel Trim, Keyless

Marks USA 5SS55N Institutional Anti-Ligature Passage Mortise Lockset with Solid Stainless Steel Trim, Keyless

The Marks USA 5SS55N is a heavy-duty institutional anti-ligature passage mortise lockset engineered for demanding commercial environments where safety and durability are paramount. Designed for keyless passage function (ANSI Function F75), the latch is retracted by knobs or levers at all times, making it ideal for high-traffic corridors, healthcare facilities, and institutional settings. Built to a 1-3/4" standard door thickness with a 2-3/4" backset, this lockset meets or exceeds all operational and security tests of ANSI A156.13-2005 for Series 5000, Grade 1, and is rated for a minimum of 1,500,000 life cycles. Solid stainless steel construction throughout ensures long-term performance in the most rigorous applications.

Key Features

• Exceptional Durability: Life tested to a minimum of 1,500,000 cycles, ensuring long-term reliability in high-traffic institutional and commercial applications.
• Anti-Ligature Safety Design: Solid stainless steel interior and exterior tapered knobs or levers recessed into thru-bolted roses, featuring safety knobs with recessed grip and finger indents (Patent #D587556) to minimize ligature risk.
• Solid Stainless Steel Construction: Solid cast stainless steel levers, solid stainless steel cylinders with solid stainless steel security collars, and a solid stainless steel latch with antifriction latch lever for superior corrosion resistance and durability.
• Precise Lock Specifications: 2-3/4" backset; adjustable bevel steel backplate measuring 1-1/4" x 8" x 7/64" thick; 3/4" reversible latch throw; 1/2" reversible auxiliary deadlatch throw; cover plate 1/16" thick with tamper-proof screws.
• Tamper-Resistant Strike: Includes a 4-7/8" curved lip stainless steel strike secured with tamper-proof screws for added security and resistance to forced entry.
• ADA-Compliant Lever Operation: Safety lever for handicapped access on clutch-operated mortise lock; levers rotate up and down freely in both locked and unlocked positions for accessible, ergonomic operation.
• Robust Internal Components: Stamped steel case 3/32" thick with zinc dichromate finish; steel hubs (9/32" on diamond, 5/16" on square) with security separator; steel hub lock arm 1/8" thick; independent spring-loaded spindles for reliable, consistent operation.
• Standard Door Preparation: ANSI A115.1 lock face cutout with 2-1/8" through hole for knob/rose assembly; front size 1-1/8" x 2-1/4" for straightforward installation on standard commercial doors.

Certifications & Compliance

• ANSI/BHMA A156.13-2005 Series 5000, Grade 1 — Meets or exceeds all operational and security tests
• ANSI/BHMA Certified
• UL Listed
• ADA Compliant
• ANSI Function F75 (Passage/Hall/Closet — Latch retracted by knobs/levers at all times)

Technical Specifications

• Series: 5SS19 Series
• Latch Throw: 9/16"
• Product Group: Mechanical Locks
• Product Subgroup: Bored Locksets
• Product Type: Cylindrical Locks
• Subcategory: Cylindrical Locks
• ANSI/BHMA: ANSI/BHMA, UL Listed
• Commercial/Residential: Commercial
• Lock Type: Cylindrical
• Function Description: Latch retracted by knobs/levers at all times
• Front Size: 1-1/8" x 2-1/4"
• ADA Compliant: Yes
• Keyed: No
• ANSI Function: F75
• Product Attribute: Cylindrical Locks
• Product Function: Passage/Hall/Closet
• Latch Type Specification: Deadlocking
• Product Category: Mechanical Locks
• Department: Door Hardware

Typical Applications

• Healthcare and Behavioral Health Facilities
• Institutional and Correctional Environments
• Educational Facilities and Schools
• Commercial Office Buildings
• Government and Municipal Buildings
• Multi-Tenant Residential and Assisted Living Properties
• High-Traffic Corridors and Common Areas

Why Marks USA 5SS55N?

Marks USA 5SS55N mortise locksets are built to the highest institutional standards, combining solid stainless steel construction throughout with a life test rating of 1,500,000 cycles minimum and full compliance with ANSI A156.13-2005 Grade 1 requirements. The anti-ligature design — featuring patented recessed safety knobs (Patent #D587556), thru-bolted roses, and tamper-proof hardware — makes this lockset the trusted choice for professionals specifying door hardware in safety-critical commercial and institutional environments.