Narrow frame doors require precise locking systems that balance strength, compliance, and installation flexibility. The Narrow Stile Mortise Lock DDML023 is engineered for slim-profile door applications where space is limited but performance standards remain uncompromised. With a compact case structure and multiple backset options ranging from 20 mm to 35 mm, this lock integrates smoothly into aluminum profiles, steel doors, and wooden narrow stile systems commonly used in commercial and architectural projects. Tested to EN12209 Grade 3 with 200,000 operational cycles and certified to EN1634 with a 240-minute fire rating, it meets strict European compliance requirements for safety-critical installations. Its narrow design combined with robust internal mechanics makes it suitable for both interior and exterior swing doors where durability, fire safety, and standardized configuration are essential.

1. Compact Backset Range

The DDML023 Narrow Stile Mortise Lock is offered with 20mm, 25mm, 30mm, and 35mm backsets for aluminum narrow-stile and metal-framed doors with restricted internal space. Door manufacturers can select the size according to profile sections, glazing positions, cylinder lengths, and fabrication drawings, improving lock-pocket accuracy and compatibility during volume door assembly.

2. 85mm or 92mm Centers

The product provides 85mm and 92mm lever-to-cylinder center distances with an 8×8mm follower for compatible handle spindles. The Narrow Stile Mortise Lock can be configured around the selected escutcheon, Euro-profile cylinder, and handle installation. Two center options help buyers serve different regional hardware practices while reducing door rework caused by dimensional mismatch.

3. Two Stainless Steel Forend Widths

The stainless steel forend is 2.5mm thick and available in 16mm or 22mm widths for compact lock pockets and wider profile openings. Radius and square end shapes accommodate different routing tools and fabrication methods. These defined dimensions allow the lock to sit accurately inside the stile and help the forend align evenly with the door-edge surface.

4. Three Bolt Material Options

DDML023 latch bolts and deadbolts are available in brass, zinc alloy, or stainless steel. The follower can be specified in brass, zinc alloy, steel, or stainless steel. Buyers can select components according to door weight, operating frequency, budget range, and installation conditions, allowing one Narrow Stile Mortise Lock platform to serve several residential and commercial project levels.

5. Five Coordinated Finishes

Finish choices include satin stainless steel, polished stainless steel, PVD, antique brass, and antique copper. They accommodate contemporary metal doors, traditional commercial interiors, and hotel hardware schemes. Radius or square forends can be matched to the lock-pocket shape, while coordinated colors simplify alignment with handles, cylinder escutcheons, hinges, and the complete project hardware schedule.

1. Retail Store Entrances

Retail stores frequently use narrow aluminum-framed glass doors where the lock must avoid glazing and internal fixing elements. The Narrow Stile Mortise Lock offers a minimum 20mm backset and a 16mm forend for restricted spaces. Its 85mm or 92mm center distance supports different handle and cylinder combinations for shopping units, street-facing stores, and showrooms.

2. Office Glass Partitions

Glass partition doors in meeting rooms, executive offices, and consultation areas require a slim frame appearance with practical locking. DDML023 offers 16mm and 22mm stainless steel forends with a 2.5mm thickness for prepared profile slots. SSS, PSS, and PVD finishes coordinate with satin, polished, or dark architectural hardware used throughout modern office interiors.

3. Apartment Aluminum Doors

Balcony doors, interior aluminum-framed doors, and shared apartment entrances can use a 20mm, 25mm, 30mm, or 35mm backset according to profile depth. The Narrow Stile Mortise Lock includes an 8×8mm follower and two center-distance options for project-specified handles and cylinders. Selectable bolt materials also support different budgets and access frequencies.

4. Hotel Dining Rooms

Hotel dining rooms, meeting areas, and leisure spaces may use narrow-framed swing doors to preserve a lighter visual profile. DDML023 offers radius and square forends for different machining methods. Antique brass, antique copper, and PVD finishes complement traditional or contemporary interiors while helping contractors standardize the Narrow Stile Mortise Lock specification across defined areas.