Corbin Russwin ML2055 Grade 1 LL Classroom Mortise Body Only

Corbin Russwin ML2055-LL Classroom Mortise Lockbody, Grade 1, ANSI F05, Field Reversible

Heavy-Duty Commercial Classroom Mortise Lock with Patented Quick Reversible Latchbolt

The Corbin Russwin ML2055-LL is a Grade 1 classroom mortise lockbody from the ML2000 Series, engineered to meet the rigorous demands of high-traffic commercial, institutional, industrial, and government applications. Conforming to ANSI function F05, this lockbody allows the latchbolt to be operated by grip from either side unless the outside grip is locked by key, at which point the latchbolt is operated by key only — while the inside grip always remains free. Constructed of heavy-gauge steel with a 1" stainless steel deadbolt and a patented Quick Reversible latchbolt, the ML2055-LL is designed for 1-3/4" (44mm) standard door thickness and features field-reversible handing for flexible installation. The ML2000 Series has been UL cycle tested above and beyond standard requirements, completing over 14.5 Million Cycles (Verification ID: V875753), making it an ideal choice for offices, schools, hospitals, hotels, and other demanding high-use environments.

Professional Features & Benefits

• ANSI/BHMA Grade 1 mortise lock per A156.13 Series 1000, Operational and Security Grade 1
• UL Cycle above and beyond: 14.5 Million Cycles (Verification ID: V875753)
• Patented Quick Reversible latchbolt — reverse handing without disassembling the lock case
• Multi-function capability: 12 functions configurable from one ML2054 lockbody
• Heavy-gauge steel lockcase 5-7/8" x 4" x 15/16"; 1" stainless steel deadbolt, 1" throw
• 3/4" (19mm) throw anti-friction two-piece latchbolt requires less force to close
• Wide variety of trim designs including Muséo®, Vineyard™, Behavioral Health (BHSS/BLSS)
• Status indicator options for locked/unlocked visibility (sectional and escutcheon trim)
• Motorized Electric Latch Retraction (MELR) available for ML20900 series
• Thru-bolted trim designs for proper alignment and increased security
• Can be used with new or existing Corbin Russwin key systems; accepts most other manufacturers' cylinders
• UL/cUL listed, UL10C positive pressure; 3-hour fire door up to 4' x 10' single or 8' x 10' pair
• Ten-year mechanical warranty; five-year MELR; two-year electrical

Technical Specifications

• Grade: ANSI/BHMA A156.13 Series 1000, Operational and Security Grade 1
• Handing: Handed; quick reversible — re-handed without disassembling the lock case
• Door Thickness: 1-3/4" (44mm) standard; optional thicknesses available
• Backset: 2-3/4" (70mm)
• Lockcase: Heavy-gauge steel, 5-7/8" (149mm) x 4" (102mm) x 15/16" (24mm)
• Armored Front: Wrought brass, bronze, or stainless steel, 8" x 1-1/4"
• Latchbolt: 2-piece mechanical with anti-friction insert, 5/8" x 1" x 3/4" (19mm) throw
• Auxiliary Latchbolt: 9/16" (14mm) effective throw; deadlocking
• Deadbolt: One-piece stainless steel, 19/32" x 1-1/4" x 1" (25mm) throw
• Strike: Wrought brass, bronze, or stainless steel, ANSI straight lip, 4-7/8" x 1-1/4" x 1-1/8" lip to center
• Cylinder: Brass, 6-pin L4 keyway, 0-bitted standard
• Spacing: C. to c. knob/lever to cylinder: 3-5/8" (92mm); knob/lever to thumbturn: 2-7/16" (62mm)
• Certifications: ANSI/BHMA A156.13 Grade 1; UL/cUL UL10C 3-hour positive pressure; ADA A117.1; California State Fire Marshal; Windstorm/Hurricane certified
• Warranty: Ten-year mechanical; five-year MELR; two-year electrical

Professional Applications

• Educational Facilities and Classroom Environments
• Commercial Office Buildings
• Healthcare Institutions and Hospitals
• Hotels and Hospitality Properties
• Government and Municipal Buildings
• Industrial and Institutional Facilities
• Multi-Tenant Residential and Mixed-Use Properties

Tamper-Resistant Design

The ML2000VR (Vandal Resistant) Series option features vandal-resistant stainless steel escutcheons with tapered edges and Torx® pin tamper resistant screws, providing an additional layer of security against abuse and forced entry in demanding environments.

Why Choose Corbin Russwin Quality?

Corbin Russwin ML2000 Series mortise locks deliver professional-grade reliability with heavy-gauge steel construction and a 1" stainless steel deadbolt, UL cycle tested to over 14.5 Million Cycles (Verification ID: V875753) — far exceeding standard requirements. Backed by a 10 Year Limited warranty and featuring the patented Quick Reversible latchbolt, the ML2055-LL is engineered for demanding commercial applications where dependable performance, life safety, and long-term security are essential.