Square Deadbolt Lock DDLK021-A and DDLK021-B offer a clean geometric appearance combined with reliable mechanical security for modern door systems. The square rosette structure delivers a sharp and contemporary visual profile, making it suitable for both residential and light commercial environments. Equipped with a solid brass cylinder and precision-engineered internal components, this deadbolt lock ensures stable locking performance and consistent operation over long-term use. The adjustable backset allows flexible installation across standard door preparations, while compatibility with common door thickness ranges simplifies project integration. Available in both single cylinder and double cylinder configurations, it supports different access control requirements, providing a balanced combination of security, adaptability, and aesthetic consistency for bulk order and project applications.

1. Single or Double Cylinder

The Square Deadbolt Lock series includes the DDLK021-A single-cylinder model and the DDLK021-B double-cylinder model. Buyers can select the configuration according to entrance management, door location, and project specifications. Both models share the same square appearance, helping residential and commercial projects maintain visual consistency while simplifying model classification and order management.

2. 65mm Square Rosette

The zinc alloy square rosette measures 65 × 65mm and coordinates with square levers, hinges, and contemporary door profiles. Its defined dimensions help door manufacturers verify the available surface area and spacing between adjacent hardware. The Square Deadbolt Lock therefore provides a consistent installed appearance and practical coverage planning for replacement or renovation projects.

3. Adjustable Dual Backset

The backset adjusts between 2-3/8 inches and 2-3/4 inches, corresponding to approximately 60mm and 70mm door-edge distances. Installers can adapt the lock to an existing bore or a new door preparation without stocking a complete lockset for each dimension. This flexibility reduces inventory variations and simplifies installation across projects containing multiple door specifications.

4. 35–45mm Door Range

DDLK021-A and DDLK021-B fit doors from 1-3/8 to 1-3/4 inches thick, equivalent to approximately 35mm to 45mm. This range covers many residential wooden doors, apartment doors, and light metal doors. Buyers can verify compatibility against the door schedule, reducing problems caused by incorrect connector lengths or unsuitable lock installation positions.

5. Brass Cylinder and Keys

The cylinder and keys are made from brass and operate with a tubular locking mechanism for independent deadbolt control. Finish choices include SSS, antique brass, antique copper, polished brass, and US10B. These options allow the Square Deadbolt Lock to coordinate with satin silver, traditional brass, copper-toned, polished, or dark architectural door hardware packages.

1. Residential Entrance Doors

Apartment, townhouse, and detached-home entrances can use the Square Deadbolt Lock to add independent deadbolt locking. Its 35mm to 45mm door compatibility covers many residential door constructions, while the adjustable 60mm or 70mm backset accommodates different preparations. Single- and double-cylinder models can be allocated according to individual door schedules and project requirements.

2. Serviced Apartments

Guest entrances, management rooms, and storage areas in serviced apartments may require different lock types with a consistent appearance. The DDLK021 series uses a 65 × 65mm square rosette that coordinates with modern square handles. Multiple finishes allow buyers to specify the Square Deadbolt Lock by floor, room category, or selected door color.

3. Private Office Rooms

Executive offices, archive rooms, finance departments, and internal storage areas can use an independent deadbolt to manage room access. The Square Deadbolt Lock features a tubular mechanism compatible with common door preparations. Its adjustable backset reduces ordering differences across door-edge dimensions, while the brass cylinder and keys support daily room-based key management.

4. Retail Store Back Doors

Retail offices, stockrooms, and rear entrances can use DDLK021-A or DDLK021-B according to the required single- or double-cylinder configuration. US10B, antique brass, and antique copper finishes coordinate with dark or traditional doors. The 35mm to 45mm thickness range supports store renovations, new installations, and centralized purchasing for multi-location retail projects.